JANUS INVESTMENT FUND
485APOS, 1997-12-15
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                                                        Registration No. 2-34393

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM N-1A

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

         Pre-Effective Amendment No.                             /__/

         Post-Effective Amendment No.   83                       /X/

                                     and/or

REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT
         OF 1940

         Amendment No.   66                                      /X/

                        (Check appropriate box or boxes.)

JANUS INVESTMENT FUND
(Exact Name of Registrant as Specified in Charter)

100 Fillmore Street, Denver, Colorado 80206-4928
Address of Principal Executive Offices           (Zip Code)

Registrant's Telephone No., including Area Code:  303-333-3863

Stephen L. Stieneker - 100 Fillmore Street, Denver, Colorado 80206-4928
(Name and Address of Agent for Service)

Approximate Date of Proposed Offering:  February 17, 1998

It is proposed that this filing will become effective (check appropriate line):
     ___  immediately upon filing pursuant to paragraph (b) of Rule 485.
     ___  on (date) pursuant to paragraph (b) of Rule 485.
     ___  60 days after filing pursuant to paragraph (a)(1) of Rule 485.
      X   on February 17, 1998, pursuant to paragraph (a)(1) of Rule 485.
     ___  75 days after filing pursuant to paragraph (a)(2) of Rule 485. 
     ___  on (date) pursuant to paragraph (a)(2) of Rule 485.

If appropriate, check the following line:
     ___  this  post-effective   amendment   designates  a  new  effective 
          date  for  a  previously  filed post-effective amendment.


<PAGE>


                              JANUS INVESTMENT FUND

                              Cross Reference Sheet
                   Between the Prospectuses and Statements of
                   Additional Information and Form N-1A Item


FORM N-1A ITEM                          CAPTION IN PROSPECTUS

PART A


1.   Cover Page                         Cover Page

2.   Synopsis                           Cover Page; Fund(s) at a Glance
                                        (Combined Income, Combined Equity and 
                                        Venture Prospectuses only); Expense 
                                        Information

3.   Condensed Financial                Financial Highlights; Understanding the
     Information                        Financial Highlights (not included in
                                        Money Market Funds - Institutional
                                        Shares Prospectus or Money Market
                                        Funds - Service Shares Prospectus); 
                                        Performance Terms (Combined Income,
                                        Combined Equity and Venture Prospectuses
                                        only); Performance (Money Market Fund -
                                        Institutional Shares and Service Shares
                                        Prospectuses only)

4.   General Description of             Fund(s) at a Glance (Combined Income,
     Registrant                         Combined Equity and Venture Prospectuses
                                        only); The Fund(s) in Detail(Combined
                                        Income, Combined Equity and Venture 
                                        Prospectuses only); Investment 
                                        Objectives and Policies (Combined Income
                                        and Combined Equity Prospectuses only); 
                                        Investment Objective and Types of
                                        Investments (Venture Prospectus only) 
                                        and Investment Objectives, Policies and
                                        Techniques (Money Market Fund -
                                        Institutional Shares and Service Shares
                                        Prospectuses only); General Portfolio
                                        Policies (Combined Income, Combined 
                                        Equity and Venture Prospectuses only);
                                        Common Investment Techniques (Money
                                        Market Fund - Institutional Shares and 
                                        Service Shares Prospectuses only); 
                                        Additional Risk Factors (not included 
                                        in Money Market Fund -

<PAGE>


                                        Institutional Shares Prospectus and 
                                        Money Market Fund - Service Shares 
                                        Prospectus); Appendix A - Glossary of 
                                        Investment Terms (Combined Income, 
                                        Combined Equity and Venture Prospectuses
                                        only); Appendix B - Explanation of
                                        Rating Categories (Combined Income
                                        Prospectus only)

5.   Management of the Fund             Management of the Fund(s) (Combined 
                                        Income, Combined Equity and Venture
                                        Prospectuses only); Investment Adviser
                                        and Administrator (Money Market Fund -
                                        Institutional Shares, Service Shares and
                                        Combined Income Prospectuses only)

5A.  Management's Discussion of         Not Applicable
     Fund Performance

6.   Capital Stock and Other            Distributions and Taxes; Shareholder's
     Securities                         Manual (Combined Income, Combined 
                                        Equity, and Venture Prospectuses only);
                                        Shareholder's Guide (Money Market
                                        Funds - Institutional Shares and Service
                                        Shares Prospectuses only)

7.   Purchase of Securities Being       Shareholder's Manual (Combined Income, 
     Offered                            Combined Equity, and Venture 
                                        Prospectuses only); Shareholder's Guide
                                        (Money Market Funds - Institutional 
                                        Shares and Service Shares Prospectuses 
                                        only)

8.   Redemption or Repurchase           Shareholder's Manual (Combined Income,
                                        Combined Equity, and Venture 
                                        prospectuses only); Shareholder's Guide
                                        (Money Market Funds - Institutional 
                                        Shares and Service Shares Prospectuses
                                        only)

9.   Pending Legal Proceedings          Not Applicable


<PAGE>


FORM N-1A ITEM                          CAPTION IN STATEMENT OF
                                        ADDITIONAL INFORMATION
PART B

10.  Cover Page                         Cover Page

11.  Table of Contents                  Table of Contents

12.  General Information and            Miscellaneous Information
     History    

13.  Investment Objectives and          Investment Policies,   Restrictions 
     Policies                           and  Policies Techniques  (Combined 
                                        Equity and Income and  Venture 
                                        Statements  of  Additional Information 
                                        only);  Investment  Policies
                                        and  Restrictions   Money  Market  Funds
                                        Statements  of  Additional   Information
                                        only);    Types   of   Securities    and
                                        Investment  Techniques;   Appendix  A  -
                                        Description of Securities Ratings (Money
                                        Market Funds  Statements  of  Additional
                                        Information   only);  Appendix   B   -
                                        Description   of  Municipal   Securities
                                        (Money   Market  Funds   Statements   of
                                        Additional Information only); Appendix A
                                        -  Explanation   of  Rating   Categories
                                        (Combined  Equity and Income and Venture
                                        Statements  of  Additional   Information
                                        only) 

14.  Management  of  the  Fund          Investment  Adviser (Combined Equity and
                                        Income   and   Venture   Statements   of
                                        Additional Information only); Investment
                                        Adviser and Administrator  (Money Market
                                        Funds     Statements    of    Additional
                                        Information only); Officers and Trustees

15.  Control Persons and Principal      Principal    Shareholders 
     Holders of Securities

                                        Investment  Adviser (Combined Equity and
16.  Investment Advisory and            Income   and   Venture   Statements   of
     Other Services                     Additional Information only); Investment
                                        Adviser and Administrator  (Money Market
                                        Funds     Statements    of    Additional
                                        Information only);  Custodian,  Transfer
                                        Agent    and    Certain    Affiliations;
                                        Portfolio  Transactions  and  Brokerage;
                                        Officers  and  Trustees;   Miscellaneous
                                        Information


<PAGE>


17.  Brokerage Allocation and           Portfolio Transactions and Brokerage
     Other Practices

18.  Capital Stock and Other            Purchase of Shares; Redemption of 
     Securities                         Shares; Miscellaneous Information

19.  Purchase, Redemption and           Purchase of Shares; Redemption of 
     Pricing of Securities Being        Shares; Shareholder Accounts
     Offered

                                        Income    Dividends,    Capital    Gains
20.  Tax Status                         Distributions  and Tax Status  (Combined
                                        Equity and Income and Venture Statements
                                        of   Additional    Information    only);
                                        Dividends  and Tax Status  (Money Market
                                        Funds     Statements    of    Additional
                                        Information   only)  


21.  Underwriters                       Custodian,  Transfer  Agent and  Certain
                                        Affiliations   

22.  Calculation of Performance         Performance Data Performance Information
     Data                               (Combined  Equity and Income and Venture
                                        Statements  of  Additional   Information
                                        only);  Performance  Data (Money  Market
                                        Funds     Statements    of    Additional
                                        Information    only)   

23.  Financial Statements               Financial Statements




<PAGE>   
 
                             JANUS INVESTMENT FUND
                               JANUS EQUITY FUNDS
 
                              100 Fillmore Street
                             Denver, CO 80206-4928
                                 (800) 525-3713
   
                              http://www.Janus.com
    
 
   
                               FEBRUARY 17, 1998
    
 
   
This Prospectus describes eleven mutual funds that emphasize growth of capital
or a combination of growth and income (the "Funds"). Janus Capital Corporation
("Janus Capital") serves as investment adviser to each Fund. Janus Capital has
been in the investment advisory business for over 27 years and currently manages
approximately $70 billion in assets.
    
 
Each Fund is a series of Janus Investment Fund (the "Trust"). The Trust is
registered with the Securities and Exchange Commission ("SEC") as an open-end
management investment company. This Prospectus contains information about the
Funds that you should consider before investing. Please read it carefully and
keep it for future reference.
 
   
Additional information about the Funds is contained in a Statement of Additional
Information ("SAI") filed with the SEC. The SAI dated February 17, 1998, is
incorporated by reference into this Prospectus. For a copy of the SAI, write or
call the Funds at the address or phone number listed above. The SEC maintains a
Web site located at http://www.sec.gov that contains the SAI, material
incorporated by reference, and other information regarding the Funds.
    
 
   
THE FUNDS' SHARES ARE NOT BANK DEPOSITS, ARE NOT ENDORSED OR GUARANTEED BY ANY
BANK, AND ARE NOT INSURED BY THE FEDERAL DEPOSIT INSURANCE CORPORATION, THE
FEDERAL RESERVE BOARD, OR ANY OTHER GOVERNMENT AGENCY.
    
 
   
THESE SECURITIES HAVE NOT BEEN APPROVED BY THE SEC NOR HAS THE SEC PASSED ON THE
ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A
CRIMINAL OFFENSE.
    
 
THIS PROSPECTUS DOES NOT CONSTITUTE AN OFFER TO SELL SECURITIES IN ANY STATE OR
OTHER JURISDICTION TO ANY PERSON TO WHOM IT IS UNLAWFUL TO MAKE SUCH AN OFFER IN
SUCH STATE OR OTHER JURISDICTION.
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                    FEBRUARY 17, 1998    1
    
<PAGE>   
 
                                    CONTENTS
 
   
<TABLE>
<S>                                            <C>
FUNDS AT A GLANCE
Brief description of each Fund...............    3
EXPENSE INFORMATION
Each Fund's annual operating expenses........    7
Financial Highlights - a summary of financial
  data.......................................    8
THE FUNDS IN DETAIL
Investment Objectives and Policies...........   16
General Portfolio Policies...................   23
Additional Risk Factors......................   25
SHAREHOLDER'S MANUAL
Types of Account Ownership...................   30
How to Open Your Janus Account...............   31
How to Purchase Shares.......................   31
How to Exchange Shares.......................   33
How to Redeem Shares.........................   34
Shareholder Services and Account Policies....   36
MANAGEMENT OF THE FUNDS
Investment Adviser and Investment
   Personnel.................................   39
Personal Investing...........................   41
Management Expenses..........................   41
Portfolio Transactions.......................   41
Other Service Providers......................   42
Other Information............................   42
DISTRIBUTIONS AND TAXES
Distributions................................   43
Taxes........................................   44
PERFORMANCE TERMS
An Explanation of Performance Terms..........   45
APPENDIX A
Glossary of Investment Terms.................   46
</TABLE>
    
 
   
 2   JANUS EQUITY FUNDS COMBINED PROSPECTUS                    FEBRUARY 17, 1998
    
<PAGE>   
 
                               FUNDS AT A GLANCE
 
   
This section is designed to provide you with a brief overview of the Funds and
their investment emphasis. A more detailed discussion of the Funds' investment
objectives and policies begins on page 16 and complete information on how to
purchase, redeem and exchange shares begins on page 31.
    
 
   
All Janus funds are no-load investments. This means you may purchase and sell
shares in any of our mutual funds without incurring any sales charges. If you
enroll in our low minimum initial investment program, you can open your account
for as little as $500 and a $100 subsequent purchase per month. Otherwise, the
minimum initial investment is $2,500 ($500 minimum for Individual Retirement
Accounts). For complete information on how to purchase, exchange and sell
shares, please see the Shareholder's Manual beginning on page 29.
    
 
GROWTH FUNDS
   
THE JANUS GROWTH FUNDS ARE DESIGNED FOR LONG-TERM INVESTORS WHO SEEK GROWTH OF
CAPITAL AND WHO CAN TOLERATE THE GREATER RISKS ASSOCIATED WITH COMMON STOCK
INVESTMENTS.
    
 
JANUS FUND
Fund Focus: A diversified fund that seeks long-term growth of capital by
investing primarily in common stocks, with an emphasis on companies with larger
market capitalizations.
 
Fund Inception: February 1970
 
Fund Manager: James P. Craig, III
   
Assistant Fund Managers: David C. Decker
    
   
                     Blaine P. Rollins
    
 
JANUS ENTERPRISE FUND
Fund Focus: A nondiversified fund that seeks long-term growth of capital by
investing primarily in common stocks, with an emphasis on securities issued by
medium-sized companies.
 
Fund Inception: September 1992
 
Fund Manager: James P. Goff
 
JANUS MERCURY FUND
Fund Focus: A diversified fund that seeks long-term growth of capital by
investing primarily in common stocks of companies of any size.
 
Fund Inception: May 1993
 
Fund Manager: Warren B. Lammert
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                    FEBRUARY 17, 1998    3
    
<PAGE>   
 
   
JANUS OLYMPUS FUND
    
Fund Focus: A nondiversified fund that seeks long-term growth of capital by
investing primarily in common stocks of companies of any size.
 
Fund Inception: December 1995
 
   
Fund Manager: Claire Young
    
 
JANUS OVERSEAS FUND
Fund Focus: A diversified fund that seeks long-term growth of capital by
investing primarily in common stocks of foreign companies.
 
Fund Inception: May 1994
 
Fund Manager: Helen Young Hayes
 
   
Assistant Fund Manager: Laurence J. Chang
    
 
   
JANUS SPECIAL SITUATIONS FUND
    
   
Fund Focus: A nondiversified fund that seeks capital appreciation by investing
primarily in common stocks that its portfolio manager believes have been
overlooked or undervalued by other investors.
    
 
   
Fund Inception: December 1996
    
 
   
Fund Manager: David C. Decker
    
 
JANUS TWENTY FUND
Fund Focus: A nondiversified fund that seeks long-term growth of capital by
normally concentrating its investments in a core position of 20-30 common
stocks.
 
Fund Inception: April 1985
 
   
Fund Manager: Scott W. Schoelzel
    
 
JANUS WORLDWIDE FUND
Fund Focus: A diversified fund that seeks long-term growth of capital by
investing primarily in common stocks of foreign and domestic issuers.
 
Fund Inception: May 1991
 
Fund Manager: Helen Young Hayes
 
   
Assistant Fund Manager: Laurence J. Chang
    
 
   
 4   JANUS EQUITY FUNDS COMBINED PROSPECTUS                    FEBRUARY 17, 1998
    
<PAGE>   
 
COMBINATION FUNDS
   
THE JANUS COMBINATION FUNDS ARE DESIGNED FOR INVESTORS WHO PRIMARILY SEEK GROWTH
OF CAPITAL WITH A DEGREE OF EMPHASIS ON INCOME. THESE FUNDS ARE NOT DESIGNED FOR
INVESTORS WHO DESIRE A CONSISTENT LEVEL OF INCOME.
    
 
JANUS BALANCED FUND
Fund Focus: A diversified fund that seeks long-term growth of capital, balanced
by current income. The Fund normally invests 40-60% of its assets in securities
selected primarily for their growth potential and 40-60% of its assets in
securities selected primarily for their income potential.
 
Fund Inception: September 1992
 
Fund Manager: Blaine P. Rollins
 
JANUS EQUITY INCOME FUND
Fund Focus: A diversified fund that seeks current income and long-term growth of
capital by investing primarily in income-producing equity securities.
 
Fund Inception: June 1996
 
Fund Manager: Blaine P. Rollins
 
JANUS GROWTH AND INCOME FUND
   
Fund Focus: A diversified fund that seeks long-term growth of capital with a
limited emphasis on income. Although the Fund normally invests at least 25% of
its assets in securities that the portfolio manager believes have income
potential, it emphasizes equity securities selected for their growth potential.
    
 
Fund Inception: May 1991
 
   
Fund Manager: David J. Corkins
    
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                    FEBRUARY 17, 1998    5
    
<PAGE>   
 
                              EXPENSE INFORMATION
 
   
The tables and example below are designed to assist you in understanding the
various costs and expenses that you will bear directly or indirectly as an
investor in the Funds. Shareholder Transaction Expenses are fees charged
directly to your individual account when you buy, sell or exchange shares. The
table below shows that you pay no such fees. Annual Fund Operating Expenses are
paid out of each Fund's assets and include fees for portfolio management,
maintenance of shareholder accounts, shareholder servicing, accounting and other
services. Expenses may vary among the Funds for a number of reasons, including
Fund size, differences in management fees, average shareholder account size, the
frequency of dividend payments, and the extent of foreign investments which
entail greater transaction costs.
    
 
    SHAREHOLDER TRANSACTION EXPENSES
    (applicable to each Fund)
 
<TABLE>
         <S>                                              <C>
         Maximum sales load imposed on purchases          None
         Maximum sales load imposed on reinvested
           dividends                                      None
         Deferred sales charges on redemptions            None
         Redemption fee*                                  None
         Exchange fee                                     None
</TABLE>
 
    * There is an $8 service fee for redemptions by wire.
 
   
 6   JANUS EQUITY FUNDS COMBINED PROSPECTUS                    FEBRUARY 17, 1998
    
<PAGE>   
 
   
ANNUAL FUND OPERATING EXPENSES(1)
    
   
(expressed as a percentage of average net assets)
    
 
   
<TABLE>
<CAPTION>
- ----------------------------------------------------------------------------
                                   MANAGEMENT   OTHER         TOTAL FUND
                                      FEE      EXPENSES   OPERATING EXPENSES
- ----------------------------------------------------------------------------
<S>                                <C>         <C>        <C>
 
Janus Fund                              0.65%     0.22%                0.87%
Janus Enterprise Fund                   0.72%     0.35%                1.07%
Janus Mercury Fund                      0.67%     0.31%                0.98%
Janus Olympus Fund                      0.73%     0.33%                1.06%
Janus Overseas Fund                     0.67%     0.36%                1.03%
Janus Special Situations Fund           0.77%     0.43%                1.20%
Janus Twenty Fund                       0.66%     0.27%                0.93%
Janus Worldwide Fund                    0.66%     0.31%                0.97%
Janus Balanced Fund                     0.76%     0.36%                1.12%
Janus Equity Income Fund                0.86%     0.62%                1.48%
Janus Growth and Income Fund            0.68%     0.30%                0.98%
</TABLE>
    
 
- --------------------------------------------------------------------------------
 
   
(1) Annual Fund Operating Expenses are based on expenses before expense offset
    arrangements for the fiscal year or period ended October 31, 1997.
    
 
   
EXAMPLE
    
Assume you invest $1,000, the Funds return 5% annually and each Fund's expense
ratio remains as listed above. The example below shows the operating expenses
that you would indirectly bear as an investor in the Funds.
 
   
<TABLE>
<CAPTION>
- -------------------------------------------------------------------------------
                                          1 YEAR   3 YEARS   5 YEARS   10 YEARS
- -------------------------------------------------------------------------------
<S>                                       <C>      <C>       <C>       <C>
 
Janus Fund                                 $ 9       $28       $48       $107
Janus Enterprise Fund                      $11       $34       $59       $131
Janus Mercury Fund                         $10       $31       $54       $120
Janus Olympus Fund                         $11       $34       $58       $129
Janus Overseas Fund                        $10       $33       $57       $126
Janus Special Situations Fund              $12       $38       $66       $145
Janus Twenty Fund                          $ 9       $30       $51       $114
Janus Worldwide Fund                       $10       $31       $54       $119
Janus Balanced Fund                        $11       $36       $62       $136
Janus Equity Income Fund                   $15       $47       $81       $177
Janus Growth and Income Fund               $10       $31       $54       $120
</TABLE>
    
 
- --------------------------------------------------------------------------------
 
THE EXAMPLE SHOULD NOT BE CONSIDERED A REPRESENTATION OF PAST OR FUTURE RETURNS
OR EXPENSES WHICH MAY BE MORE OR LESS THAN THOSE SHOWN.
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                    FEBRUARY 17, 1998    7
    
<PAGE>   
 
                              FINANCIAL HIGHLIGHTS
 
   
Unless otherwise noted, the information below is for fiscal periods ending on
October 31 of each year. The accounting firm of Price Waterhouse LLP has audited
the Funds' financial statements beginning with the year ended October 31, 1990.
Their report is included in the Funds' Annual Reports, which are incorporated by
reference into the SAI. A DETAILED EXPLANATION OF THE FINANCIAL HIGHLIGHTS CAN
BE FOUND ON PAGE 15.
    
 
   
<TABLE>
<CAPTION>
                                                                  JANUS FUND
                                                  1997+     1996      1995      1994     1993
<S>                                              <C>       <C>       <C>       <C>      <C>
- ----------------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD                    $23.37    $19.62   $20.81   $18.86
- ----------------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income                                     0.31      0.16     0.17     0.26
 3. Net gains or (losses) on securities (both
    realized and unrealized)                                  4.23      3.99   (0.03)     2.88
- ----------------------------------------------------------------------------------------------
 4. Total from investment operations                          4.54      4.15     0.14     3.14
- ----------------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)                  (0.13)    (0.01)   (0.39)   (0.29)
 6. Distributions (from capital gains)                      (1.13)    (0.39)   (0.94)   (0.90)
- ----------------------------------------------------------------------------------------------
 7. Total distributions                                     (1.26)    (0.40)   (1.33)   (1.19)
- ----------------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                          $26.65    $23.37   $19.62   $20.81
- ----------------------------------------------------------------------------------------------
 9. Total return*                                           20.31%    21.62%    0.75%   17.41%
- ----------------------------------------------------------------------------------------------
10. Net assets, end of period (in millions)                $15,313   $11,963   $9,647   $9,098
11. Average net assets for the period (in
    millions)                                              $13,753   $10,560   $9,339   $7,336
12. Ratio of gross expenses to average net
    assets**                                                 0.86%     0.87%      N/A      N/A
13. Ratio of net expenses to average net
    assets**                                                 0.85%     0.86%    0.91%    0.92%
14. Ratio of net investment income to average
    net assets**                                             0.91%     1.25%    1.12%    1.55%
15. Portfolio turnover rate**                                 104%      118%     139%     127%
16. Average commission rate                                 $.0558       N/A      N/A      N/A
- ----------------------------------------------------------------------------------------------
</TABLE>
    
 
 * Total return is not annualized for periods of less than one full year.
** Annualized for periods of less than one full year.
   
 + [To be filed by Amendment]
    
 
   
 8   JANUS EQUITY FUNDS COMBINED PROSPECTUS                    FEBRUARY 17, 1998
    
<PAGE>   
 
(continued)
 
   
<TABLE>
<CAPTION>
                                                                 JANUS FUND
                                                  1992     1991     1990     1989     1988
<S>                                              <C>      <C>      <C>      <C>      <C>
- -------------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD         $18.27   $13.25   $16.36   $12.11   $12.39
- -------------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income                         0.23     0.25     0.25     0.22      0.60
 3. Net gains or (losses) on securities (both
    realized and unrealized)                      1.46     5.09    (0.67)    4.59      1.05
- -------------------------------------------------------------------------------------------
 4. Total from investment operations              1.69     5.34    (0.42)    4.81      1.65
- -------------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)       (0.19)   (0.31)   (0.19)   (0.56)   (0.32)
 6. Distributions (from capital gains)           (0.91)   (0.01)   (2.50)      --    (1.61)
- -------------------------------------------------------------------------------------------
 7. Total distributions                          (1.10)   (0.32)   (2.69)   (0.56)   (1.93)
- -------------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD               $18.86   $18.27   $13.25   $16.36   $12.11
- -------------------------------------------------------------------------------------------
 9. Total return*                                9.35%    40.95%   (3.68%)  41.67%   15.83%
- -------------------------------------------------------------------------------------------
10. Net assets, end of period (in millions)      $4,989   $2,598   $1,049    $673      $391
11. Average net assets for the period (in
    millions)                                    $3,871   $1,785    $930     $487      $382
12. Ratio of gross expenses to average net
    assets**                                       N/A      N/A      N/A      N/A       N/A
13. Ratio of net expenses to average net
    assets**                                     0.97%    0.98%    1.02%    0.92%     0.98%
14. Ratio of net investment income to average
    net assets**                                 1.54%    1.77%    2.11%    1.68%     4.99%
15. Portfolio turnover rate**                     153%     132%     307%     205%      175%
16. Average commission rate                        N/A      N/A      N/A      N/A       N/A
- -------------------------------------------------------------------------------------------
</TABLE>
    
 
 * Total return is not annualized for periods of less than one full year.
** Annualized for periods of less than one full year.
 
   
<TABLE>
<CAPTION>
                                                           JANUS ENTERPRISE FUND
                                            1997+     1996     1995     1994     1993    1992(1)
<S>                                         <C>      <C>      <C>      <C>      <C>      <C>
- ------------------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD             $27.14   $24.43   $21.87   $17.09   $15.00
- ------------------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income (loss)                         --     0.52   (0.06)     0.04       --
 3. Net gains or (losses) on securities
    (both realized and unrealized)                     5.85     3.09     3.18     4.76     2.09
- -----------------------------------------------------------------------------------------------
 4. Total from investment operations                   5.85     3.61     3.12     4.80     2.09
- -----------------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)               --   (0.52)   (0.02)   (0.02)       --
 6. Distributions (from capital gains)               (1.80)   (0.38)   (0.54)       --       --
- -----------------------------------------------------------------------------------------------
 7. Total distributions                              (1.80)   (0.90)   (0.56)   (0.02)       --
- -----------------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                   $31.19   $27.14   $24.43   $21.87   $17.09
- -----------------------------------------------------------------------------------------------
 9. Total return*                                    22.43%   15.46%   14.56%   28.09%   13.93%
- -----------------------------------------------------------------------------------------------
10. Net assets, end of period (in
    millions)                                          $732     $459     $370     $239       $8
11. Average net assets for the period (in
    millions)                                          $596     $408     $270     $188       $2
12. Ratio of gross expenses to average net
    assets**                                          1.14%    1.26%      N/A      N/A      N/A
13. Ratio of net expenses to average net
    assets**                                          1.12%    1.23%    1.25%    1.36%    2.50%
14. Ratio of net investment income/(loss)
    to average net assets**                          (0.78)    0.02%   (0.32%)   0.14%   (0.81%)
15. Portfolio turnover rate**                           93%     194%     193%     201%      53%
16. Average commission rate                          $.0333      N/A      N/A      N/A      N/A
- -----------------------------------------------------------------------------------------------
</TABLE>
    
 
(1) Fiscal period from September 1, 1992 (inception) to October 31, 1992.
 * Total return is not annualized for periods of less than one full year.
** Annualized for periods of less than one full year.
   
 + [To be filed by Amendment]
    
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                    FEBRUARY 17, 1998    9
    
<PAGE>   
 
   
<TABLE>
<CAPTION>
                                                             JANUS MERCURY FUND
                                               1997+      1996      1995      1994     1993(1)
<S>                                            <C>       <C>       <C>       <C>       <C>
- ---------------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD                 $17.38    $14.12    $11.70    $10.00
- ---------------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income                                  0.14      0.16      0.02    (0.01)
 3. Net gains or (losses) on securities (both
    realized and unrealized)                               2.74      3.37      2.40      1.71
- ---------------------------------------------------------------------------------------------
 4. Total from investment operations                       2.88      3.53      2.42      1.70
- ---------------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)                   --    (0.16)        --        --
 6. Distributions (from capital gains)                   (2.06)    (0.11)        --        --
- ---------------------------------------------------------------------------------------------
 7. Total distributions                                  (2.06)    (0.27)        --        --
- ---------------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                       $18.20    $17.38    $14.12    $11.70
- ---------------------------------------------------------------------------------------------
 9. Total return*                                        18.18%    25.53%    20.68%    17.00%
- ---------------------------------------------------------------------------------------------
10. Net assets, end of period (in millions)              $2,002    $1,521      $596      $113
11. Average net assets for the period (in
    millions)                                            $1,839    $1,116      $258       $67
12. Ratio of gross expenses to average net
    assets**                                              1.02%     1.14%       N/A       N/A
13. Ratio of net expenses to average net
    assets**                                              1.00%     1.12%     1.33%     1.75%
14. Ratio of net investment income/(loss) to
    average net assets**                                  0.45%     0.50%     0.25%    (0.40%)
15. Portfolio turnover rate**                              177%      201%      283%      151%
16. Average commission rate                              $.0383       N/A       N/A       N/A
- ---------------------------------------------------------------------------------------------
</TABLE>
    
 
(1) Fiscal period from May 3, 1993 (inception) to October 31, 1993.
 * Total return is not annualized for periods of less than one full year.
** Annualized for periods of less than one full year.
   
 + [To be filed by Amendment]
    
 
   
<TABLE>
<CAPTION>
                                                 JANUS
                                                OLYMPUS
                                                  FUND                JANUS OVERSEAS FUND
                                            1997+    1996(1)   1997+     1996     1995    1994(2)
<S>                                         <C>      <C>       <C>      <C>      <C>      <C>
- ------------------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD              $12.00            $11.58   $10.36   $10.00
- ------------------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income (loss)                        0.13              0.10     0.12   (0.02)
 3. Net gains or (losses) on securities
    (both realized and unrealized)                      2.73              3.34     1.10     0.38
- ------------------------------------------------------------------------------------------------
 4. Total from investment operations                    2.86              3.44     1.22     0.36
- ------------------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)                --            (0.11)       --       --
 6. Distributions (from capital gains)                    --            (0.10)       --       --
- ------------------------------------------------------------------------------------------------
 7. Total distributions                                   --            (0.21)       --       --
- ------------------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                    $14.86            $14.81   $11.58   $10.36
- ------------------------------------------------------------------------------------------------
 9. Total return*                                     23.83%            30.19%   11.78%    3.60%
- ------------------------------------------------------------------------------------------------
10. Net assets, end of period (in
    millions)                                           $432              $773     $111      $64
11. Average net assets for the period (in
    millions)                                           $276              $335      $78      $37
12. Ratio of gross expenses to average net
    assets**                                           1.17%             1.26%    1.76%      N/A
13. Ratio of net expenses to average net
    assets**                                           1.15%             1.23%    1.73%    2.16%
14. Ratio of net investment income/(loss)
    to average net assets**                            1.64%             0.73%    0.36%   (0.64%)
15. Portfolio turnover rate**                           303%               71%     188%     181%
16. Average commission rate                           $.0336            $.0234      N/A      N/A
- ------------------------------------------------------------------------------------------------
</TABLE>
    
 
(1) Fiscal period from December 29, 1995 (inception) to October 31, 1996.
(2) Fiscal period from May 2, 1994 (inception) to October 31, 1994.
 * Total return is not annualized for periods of less than one full year.
** Annualized for periods of less than one full year.
   
 + [To be filed by Amendment]
    
 
   
 10   JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
   
<TABLE>
<CAPTION>
                                                           JANUS SPECIAL SITUATIONS FUND
                                                                     1997(1)+
<S>                                                        <C>
- --------------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD                                   $
- --------------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income                                                 --
 3. Net gains or (losses) on securities (both realized
    and unrealized)
- --------------------------------------------------------------------------------------------
 4. Total from investment operations
- --------------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)                                --
 6. Distributions (from capital gains)                                    --
- --------------------------------------------------------------------------------------------
 7. Total distributions                                                   --
- --------------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                                         $
- --------------------------------------------------------------------------------------------
 9. Total return*                                                          %
- --------------------------------------------------------------------------------------------
10. Net assets, end of period (in millions)                                $
11. Average net assets for the period (in millions)                        $
12. Ratio of gross expenses to average net assets**                        %
13. Ratio of net expenses to average net assets**                          %
14. Ratio of net investment income to average net
    assets**                                                               %
15. Portfolio turnover rate**                                              %
16. Average commission rate                                                $
- --------------------------------------------------------------------------------------------
</TABLE>
    
 
   
(1) Fiscal period from December 31, 1996 (inception) to October 31, 1997.
    
   
 * Total return is not annualized.
    
   
** Annualized.
    
   
 + [To be filed by Amendment]
    
 
   
<TABLE>
<CAPTION>
                                                              JANUS TWENTY FUND
                                             1997+     1996     1995     1994     1993    1992(1)
<S>                                          <C>      <C>      <C>      <C>      <C>      <C>
- -------------------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD              $30.12   $24.24   $25.85   $22.75    $22.17
- -------------------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income                               0.37     0.01     0.16    0.17       0.09
 3. Net gains or (losses) on securities
    (both realized and unrealized)                      6.68     5.94   (1.07)    3.31       0.49
- -------------------------------------------------------------------------------------------------
 4. Total from investment operations                    7.05     5.95   (0.91)    3.48       0.58
- -------------------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)                --   (0.07)   (0.25)   (0.18)        --
 6. Distributions (from capital gains)                (5.27)       --   (0.45)   (0.20)        --
- -------------------------------------------------------------------------------------------------
 7. Total distributions                               (5.27)   (0.07)   (0.70)   (0.38)        --
- -------------------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                    $31.90   $30.12   $24.24   $25.85    $22.75
- -------------------------------------------------------------------------------------------------
 9. Total return*                                     27.59%   24.67%   (3.52%)  15.39%     2.62%
- -------------------------------------------------------------------------------------------------
10. Net assets, end of period (in millions)           $3,937   $2,996   $2,743   $3,749    $2,434
11. Average net assets for the period (in
    millions)                                         $3,386   $2,716   $3,051   $3,546    $2,221
12. Ratio of gross expenses to average net
    assets**                                           0.93%    1.00%      N/A     N/A        N/A
13. Ratio of net expenses to average net
    assets**                                           0.92%    0.99%    1.02%   1.05%      1.12%
14. Ratio of net investment income to
    average net assets**                               0.67%    0.62%    0.57%   0.87%      1.27%
15. Portfolio turnover rate**                           137%     147%     102%     99%        79%
16. Average commission rate                           $.0571      N/A      N/A     N/A        N/A
- -------------------------------------------------------------------------------------------------
</TABLE>
    
 
(1) Fiscal period from June 1, 1992 to October 31, 1992.
   
 * Total return is not annualized for periods of less than one full year.
    
** Annualized for periods of less than one full year.
   
 + [To be filed by Amendment]
    
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    11
    
<PAGE>   
 
   
(continued)
    
 
   
<TABLE>
<CAPTION>
                                                                  JANUS TWENTY FUND
                                                   1992(1)   1991(1)   1990(1)   1989(1)   1988(1)
<S>                                                <C>       <C>       <C>       <C>       <C>
- ---------------------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD            $18.88   $16.01    $13.05     $9.66     $13.69
- ---------------------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income                             0.11     0.16      0.05      0.46       0.42
 3. Net gains or (losses) on securities (both
    realized and unrealized)                          3.62     2.90      3.35      3.73     (2.86)
- ---------------------------------------------------------------------------------------------------
 4. Total from investment operations                  3.73     3.06      3.40      4.19     (2.44)
- ---------------------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)          (0.02)   (0.19)    (0.02)    (0.80)     (0.41)
 6. Distributions (from capital gains)              (0.42)       --    (0.42)        --     (1.18)
- ---------------------------------------------------------------------------------------------------
 7. Total distributions                             (0.44)   (0.19)    (0.44)    (0.80)     (1.59)
- ---------------------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                  $22.17   $18.88    $16.01    $13.05      $9.66
- ---------------------------------------------------------------------------------------------------
 9. Total return*                                   19.60%   19.43%    26.36%    45.89%    (17.13%)
- ---------------------------------------------------------------------------------------------------
10. Net assets, end of period (in millions)         $2,081     $556      $175       $20        $13
11. Average net assets for the period (in
    millions)                                       $1,188     $294       $64       $10        $16
12. Ratio of gross expenses to average net
    assets**                                           N/A      N/A       N/A       N/A        N/A
13. Ratio of net expenses to average net assets**    1.01%    1.07%     1.32%     1.88%      1.70%
14. Ratio of net investment income to average net
    assets**                                         1.08%    1.30%     1.28%     0.68%      3.35%
15. Portfolio turnover rate**                          83%     163%      228%      220%       317%
16. Average commission rate                            N/A      N/A       N/A       N/A        N/A
- ---------------------------------------------------------------------------------------------------
</TABLE>
    
 
   
(1) Fiscal year ended on May 31st of each year.
    
 * Total return is not annualized for periods of less than one full year.
** Annualized for periods of less than one full year.
 
   
<TABLE>
<CAPTION>
                                                           JANUS WORLDWIDE FUND
                                       1997+     1996     1995     1994     1993     1992    1991(1)
<S>                                    <C>      <C>      <C>      <C>      <C>      <C>      <C>
- ----------------------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF
    PERIOD                                      $27.65   $27.00   $24.16   $18.95   $17.45    $15.00
- ----------------------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income                         0.49     0.81     0.15     0.14     0.16        --
 3. Net gains or (losses) on
    securities (both realized and
    unrealized)                                   7.79     1.39     3.34     5.29     1.39      2.45
- ----------------------------------------------------------------------------------------------------
 4. Total from investment operations              8.28     2.20     3.49     5.43     1.55      2.45
- ----------------------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment
    income)                                     (0.26)   (0.54)   (0.27)   (0.22)       --        --
 6. Distributions (from capital
    gains)                                      (1.07)   (1.01)   (0.38)       --   (0.05)        --
- ----------------------------------------------------------------------------------------------------
 7. Total distributions                         (1.33)   (1.55)   (0.65)   (0.22)   (0.05)        --
- ------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD              $34.60   $27.65   $27.00   $24.16   $18.95    $17.45
- ----------------------------------------------------------------------------------------------------
 9. Total return*                               31.00%    8.89%   14.76%   28.79%    9.20%    16.00%
- ----------------------------------------------------------------------------------------------------
10. Net assets, end of period (in
    millions)                                   $4,467   $1,804   $1,587     $755     $161       $18
11. Average net assets for the period
    (in millions)                               $2,953   $1,622   $1,244     $379      $80        $7
12. Ratio of gross expenses to
    average net assets**                         1.02%    1.24%      N/A      N/A      N/A       N/A
13. Ratio of net expenses to average
    net assets**                                 1.01%    1.23%    1.12%    1.32%    1.73%     2.50%
14. Ratio of net investment income to
    average net assets**                         0.73%    0.99%    0.42%    0.92%    1.74%     0.02%
15. Portfolio turnover rate**                      80%     142%     158%     124%     147%       40%
16. Average commission rate                     $.0311      N/A      N/A      N/A      N/A       N/A
- ----------------------------------------------------------------------------------------------------
</TABLE>
    
 
(1) Fiscal period from May 15, 1991 (inception) to October 31, 1991.
   
 * Total return is not annualized for periods of less than one full year.
    
** Annualized for periods of less than one full year.
   
 + [To be filed by Amendment]
    
 
   
 12   JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
   
<TABLE>
<CAPTION>
                                                              JANUS BALANCED FUND
                                              1997+     1996     1995     1994     1993    1992(1)
<S>                                           <C>      <C>      <C>      <C>      <C>      <C>
- --------------------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD               $13.72   $12.17   $12.23   $10.64    $10.00
- --------------------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income                                0.33     0.61     0.27     0.19        --
 3. Net gains or (losses) on securities
    (both realized and unrealized)                       2.22     1.52   (0.09)     1.56      0.64
- --------------------------------------------------------------------------------------------------
 4. Total from investment operations                     2.55     2.13     0.18     1.75      0.64
- --------------------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)             (0.26)   (0.58)   (0.24)   (0.16)        --
 6. Distributions (from capital gains)                 (0.81)       --       --       --        --
- --------------------------------------------------------------------------------------------------
 7. Total distributions                                (1.07)   (0.58)   (0.24)   (0.16)        --
- --------------------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                     $15.20   $13.72   $12.17   $12.23    $10.64
- --------------------------------------------------------------------------------------------------
 9. Total return*                                      19.39%   18.26%    1.51%   16.54%     6.40%
- --------------------------------------------------------------------------------------------------
10. Net assets, end of period (in millions)              $207     $125      $94      $73        $2
11. Average net assets for the period (in
    millions)                                            $159     $107      $86      $44        $1
12. Ratio of gross expenses to average net
    assets**                                            1.23%    1.35%      N/A      N/A       N/A
13. Ratio of net expenses to average net
    assets**                                            1.21%    1.32%    1.42%    1.70%     2.50%
14. Ratio of net investment income to
    average net assets**                                2.35%    2.52%    2.28%    2.15%   (0.12%)
15. Portfolio turnover rate**                            151%     185%     167%     131%      130%
16. Average commission rate                            $.0428      N/A      N/A      N/A       N/A
- --------------------------------------------------------------------------------------------------
</TABLE>
    
 
   
(1) Fiscal period from September 1, 1992 (inception) to October 31, 1992.
    
 * Total return is not annualized for periods of less than one full year.
** Annualized for periods of less than one full year.
   
 + [To be filed by Amendment]
    
 
   
<TABLE>
<CAPTION>
                                                                  JANUS EQUITY
                                                                  INCOME FUND
                                                              1997+        1996(1)
<S>                                                           <C>          <C>
- ----------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD                                    $10.00
- ----------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income                                                     0.07
 3. Net gains or (losses) on securities (both realized and
    unrealized)                                                               1.25
- ----------------------------------------------------------------------------------
 4. Total from investment operations                                          1.32
- ----------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)                                  (0.03)
 6. Distributions (from capital gains)                                          --
- ----------------------------------------------------------------------------------
 7. Total distributions                                                     (0.03)
- ----------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                                          $11.29
- ----------------------------------------------------------------------------------
 9. Total return*                                                           13.20%
- ----------------------------------------------------------------------------------
10. Net assets, end of period (in millions)                                    $30
11. Average net assets for the period (in millions)                            $21
12. Ratio of gross expenses to average net assets**                          1.79%
13. Ratio of net expenses to average net assets**                            1.71%
14. Ratio of net investment income to average net assets**                   3.09%
15. Portfolio turnover rate**                                                 325%
16. Average commission rate                                                 $.0350
- ----------------------------------------------------------------------------------
</TABLE>
    
 
(1) Fiscal period from June 28, 1996 (inception) to October 31, 1996.
   
 * Total return is not annualized for periods of less than one full year.
    
** Annualized for periods of less than one full year.
   
 + [To be filed by Amendment]
    
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    13
    
<PAGE>   
 
   
<TABLE>
<CAPTION>
                                                          JANUS GROWTH AND INCOME FUND
                                          1997+     1996     1995     1994     1993     1992    1991(1)
<S>                                       <C>      <C>      <C>      <C>      <C>      <C>      <C>
- ------------------------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD           $18.13   $14.69   $15.24   $12.95   $12.13   $10.00
- ------------------------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income                            0.16     0.11     0.19     0.14     0.17     0.02
 3. Net gains or (losses) on securities
    (both realized and unrealized)                   4.01     3.43   (0.31)     2.29     0.80     2.13
- ------------------------------------------------------------------------------------------------------
 4. Total from investment operations                 4.17     3.54   (0.12)     2.43     0.97     2.15
- ------------------------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment
    income)                                        (0.08)   (0.10)   (0.10)   (0.14)   (0.15)   (0.02)
 6. Distributions (from capital gains)             (2.17)       --   (0.33)       --       --       --
- ------------------------------------------------------------------------------------------------------
 7. Total distributions                            (2.25)   (0.10)   (0.43)   (0.14)   (0.15)   (0.02)
- ------------------------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                 $20.05   $18.13   $14.69   $15.24   $12.95   $12.13
- ------------------------------------------------------------------------------------------------------
 9. Total return*                                  25.56%   24.20%   (0.76%)  18.81%    7.98%   21.50%
- ------------------------------------------------------------------------------------------------------
10. Net assets, end of period (in
    millions)                                      $1,033     $583     $490     $519     $244      $56
11. Average net assets for the period
    (in millions)                                    $773     $498     $500     $404     $157      $21
12. Ratio of gross expenses to average
    net assets**                                    1.05%    1.19%      N/A      N/A      N/A      N/A
13. Ratio of net expenses to average net
    assets**                                        1.03%    1.17%    1.22%    1.28%    1.52%    2.33%
14. Ratio of net investment income to
    average net assets**                            0.70%    1.11%    1.26%    1.13%    1.61%    0.76%
15. Portfolio turnover rate**                        153%     195%     123%     138%     120%      14%
16. Average commission rate                        $.0520      N/A      N/A      N/A      N/A      N/A
- ------------------------------------------------------------------------------------------------------
</TABLE>
    
 
   
(1) Fiscal period from May 15, 1991 (inception) to October 31, 1991.
    
 * Total return is not annualized for periods of less than one full year.
** Annualized for periods of less than one full year.
   
 + [To be filed by Amendment]
    
 
   
 14   JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
                               UNDERSTANDING THE
                              FINANCIAL HIGHLIGHTS
 
This section is designed to help you better understand the information
summarized in the Financial Highlights tables. The tables contain important
historical operating information that may be useful in making your investment
decision or understanding how your investment has performed. The Funds' Annual
Reports contain additional information about each Fund's performance, including
a comparison to an appropriate securities index. For a copy of your Fund's
Annual Report, call 1-800-525-8983.
 
NET ASSET VALUE ("NAV") is the value of a single share of a Fund. It is computed
by adding the value of all of a Fund's investments and other assets, subtracting
any liabilities and dividing the result by the number of shares outstanding. The
difference between line 1 and line 8 in the Financial Highlights tables
represents the change in value of a share of a Fund over the fiscal period, but
not its total return.
 
NET INVESTMENT INCOME is the per share amount of dividends and interest income
earned on securities held by a Fund, less Fund expenses. DIVIDENDS (FROM NET
INVESTMENT INCOME) are the per share amount that a Fund paid from net investment
income.
 
NET GAINS OR (LOSSES) ON SECURITIES is the per share increase or decrease in
value of the securities a Fund holds. A gain (or loss) is realized when
securities are sold. A gain (or loss) is unrealized when securities increase or
decrease in value but are not sold. DISTRIBUTIONS (FROM CAPITAL GAINS) are the
per share amount that a Fund paid from net realized gains.
 
TOTAL RETURN is the percentage increase or decrease in the value of an
investment over a stated period of time. A total return percentage includes both
changes in NAV and income. For the purposes of calculating total return, it is
assumed that dividends and distributions are reinvested at the NAV on the day of
the distribution. A FUND'S TOTAL RETURN CANNOT BE COMPUTED DIRECTLY FROM THE
FINANCIAL HIGHLIGHTS TABLES.
 
   
RATIO OF GROSS EXPENSES TO AVERAGE NET ASSETS is the total of a Fund's operating
expenses before expense offset arrangements divided by its average net assets
for the stated period. RATIO OF NET EXPENSES TO AVERAGE NET ASSETS reflects
reductions in a Fund's expenses through the use of brokerage commissions and
uninvested cash balances earning interest or balance credits.
    
 
RATIO OF NET INVESTMENT INCOME TO AVERAGE NET ASSETS is a Fund's net investment
income divided by its average net assets for the stated period.
 
PORTFOLIO TURNOVER RATE is a measure of the amount of a Fund's buying and
selling activity. It is computed by dividing total purchases or sales, whichever
is less, by the average monthly market value of a Fund's portfolio securities.
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    15
    
<PAGE>   
 
   
AVERAGE COMMISSION RATE is the total of a Fund's agency commissions paid on
equity securities trades divided by the number of shares purchased and sold.
    
 
                              THE FUNDS IN DETAIL
 
   
This section takes a closer look at the Funds' investment objectives, policies
and the securities in which they invest. Policies that are noted as
"fundamental" cannot be changed without a shareholder vote. All other policies,
including each Fund's investment objective, are not fundamental and may be
changed by the Funds' Trustees without a shareholder vote. You will be notified
of any material changes.
    
 
   
You should carefully consider your own investment goals, time horizon (the
amount of time you plan to hold your shares of a Fund) and risk tolerance before
investing in a Fund. If there is a material change in a Fund's objective or
policies, you should consider whether that Fund remains an appropriate
investment for you. There is no guarantee that any Fund will meet its investment
objective.
    
 
   
You should also carefully review the "Additional Risk Factors" section of this
Prospectus for a more detailed discussion of the risks associated with certain
investment techniques. Appendix A includes more detailed descriptions of
investment terms used throughout this Prospectus.
    
 
- --------------------------------------------------------------------------------
 
GROWTH FUNDS
 
<TABLE>
<S>                                                   <C>
Investment Objective:...............................  Growth of Capital
Primary Holdings:...................................  Common Stocks
Shareholder's Investment Horizon:...................  Long-Term
</TABLE>
 
- --------------------------------------------------------------------------------
 
   
JANUS FUND
    
   
The investment objective of this Fund is long-term growth of capital in a manner
consistent with the preservation of capital. It is a diversified fund that
pursues its objective by investing primarily in common stocks of issuers of any
size. Janus Fund was first offered to the public in 1970 and has the largest
asset base of the Funds. This Fund generally invests in larger, more established
issuers.
    
 
JANUS ENTERPRISE FUND
   
The investment objective of this Fund is long-term growth of capital. It is a
nondiversified fund that pursues its objective by normally investing at least
50% of its equity assets in securities issued by medium-sized companies.
Medium-sized companies are those whose market capitalizations fall within the
range of companies in the S&P MidCap 400 Index (the "MidCap Index"). Companies
whose capitalization falls outside this range after the Fund's initial purchase
continue to be considered medium-sized companies for the purpose of this policy.
As of December 31, 1997, the MidCap Index included companies with
capitalizations between approximately $     million to $     billion. The range
of the MidCap Index is expected to change on a regular basis. Subject to the
above policy, the Fund may also invest in smaller or larger issuers.
    
 
   
 16   JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
JANUS MERCURY FUND
   
The investment objective of this Fund is long-term growth of capital. It is a
diversified fund that pursues its objective by investing primarily in common
stocks of issuers of any size, which may include larger well-established issuers
and/or smaller emerging growth companies.
    
 
JANUS OLYMPUS FUND
   
The investment objective of this Fund is long-term growth of capital. It is a
nondiversified fund that pursues its objective by investing primarily in common
stocks of issuers of any size, which may include larger well-established issuers
and/or smaller emerging growth companies.
    
 
JANUS OVERSEAS FUND
The investment objective of this Fund is long-term growth of capital. It is a
diversified fund that pursues its objective primarily through investments in
common stocks of issuers located outside the United States. The Fund has the
flexibility to invest on a worldwide basis in companies and other organizations
of any size, regardless of country of organization or place of principal
business activity. The Fund normally invests at least 65% of its total assets in
securities of issuers from at least five different countries, excluding the
United States. Although the Fund intends to invest substantially all of its
assets in issuers located outside the United States, it may at times invest in
U.S. issuers and it may at times invest all of its assets in fewer than five
countries or even a single country.
 
   
JANUS SPECIAL SITUATIONS FUND
    
   
The investment objective of this Fund is capital appreciation. It is a
nondiversified fund that pursues its objective by investing primarily in common
stocks of domestic and foreign issuers. The Fund seeks investments in issuers
that its portfolio manager believes have been overlooked or undervalued by other
investors in connection with a significant change or development affecting the
issuer's business ("special situations"). The Fund places particular emphasis on
issuers that have, or that the portfolio manager believes will have, higher free
cash flows. Although the Fund emphasizes these types of companies, it may invest
in other companies that the portfolio manager believes have the potential for
significant capital appreciation.
    
 
JANUS TWENTY FUND
   
The investment objective of this Fund is long-term growth of capital. It is a
nondiversified fund that pursues its objective by normally concentrating its
investments in a core position of 20-30 common stocks.
    
 
JANUS WORLDWIDE FUND
The investment objective of this Fund is long-term growth of capital in a manner
consistent with the preservation of capital. It is a diversified fund that
pursues its objective primarily through investments in common stocks of foreign
and domestic issuers. The Fund has the flexibility to invest on a worldwide
basis in companies and other organizations of any size, regardless of country of
organization or place of
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    17
    
<PAGE>   
 
principal business activity. Janus Worldwide Fund normally invests in issuers
from at least five different countries, including the United States. The Fund
may at times invest in fewer than five countries or even a single country.
 
GROWTH FUNDS
   
Each of the Growth Funds invests primarily in common stocks of foreign and
domestic companies. However, the percentage of each Fund's assets invested in
common stocks will vary and each Fund may at times hold substantial positions in
cash equivalents or interest bearing securities. See "General Portfolio
Policies" on page 23. Each Fund may invest to a lesser degree in other types of
securities including preferred stock, warrants, convertible securities and debt
securities when its portfolio manager perceives an opportunity for capital
growth from such securities or to receive a return on idle cash. The Funds may
purchase securities on a when-issued, delayed delivery or forward commitment
basis. The Funds may invest up to 25% of their assets in mortgage- and
asset-backed securities, up to 10% of their assets in zero coupon, pay-in-kind
and step coupon securities, and without limit in indexed/structured securities.
No Fund will invest 35% or more of its assets in high-yield/high-risk
securities. Each of the Growth Funds may use futures, options and other
derivatives for hedging purposes or for non-hedging purposes such as seeking to
enhance return. See "Additional Risk Factors" on pages 25-28 for a discussion of
the risks associated with derivatives.
    
 
   
Although Janus Worldwide Fund and Janus Overseas Fund are committed to foreign
investing, all of the Growth Funds may invest without limit in foreign equity
and debt securities. The Funds may invest directly in foreign securities
denominated in a foreign currency and not publicly traded in the United States.
Other ways of investing in foreign securities include depositary receipts or
shares, and passive foreign investment companies. See "Additional Risk Factors"
on pages 25-28 for a discussion of the risks associated with foreign investing.
    
 
   
Although Janus Special Situations Fund emphasizes investments in "special
situations," each of the Growth Funds may invest in such issuers from time to
time. A special situation arises when, in the opinion of a Fund's portfolio
manager, the securities of a particular issuer will be recognized and appreciate
in value due to a specific development with respect to that issuer. Investments
in special situations may carry an additional risk of loss in the event that the
anticipated development does not occur or does not attract the expected
attention. Special situations are discussed in more detail in the questions
below.
    
 
THE FOLLOWING QUESTIONS ARE DESIGNED TO HELP YOU BETTER UNDERSTAND AN INVESTMENT
IN THE JANUS GROWTH FUNDS.
 
Q:   HOW ARE COMMON STOCKS SELECTED?
 
A:   Each of the Growth Funds invests substantially all of its assets in common
     stocks to the extent its portfolio manager believes that the relevant
     market environment favors profitable investing in those securities.
Portfolio managers generally take a "bottom up" approach to building their
portfolios. In other words, they seek to identify individual companies with
earnings growth potential
   
 18   JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
that may not be recognized by the market at large. Although themes may emerge in
any Fund, securities are generally selected without regard to any defined
industry sector or other similarly defined selection procedure. Realization of
income is not a significant investment consideration for the Growth Funds. Any
income realized on the Growth Funds' investments will be incidental to their
objectives.
   
Q:   ARE THE SAME CRITERIA USED 
     TO SELECT FOREIGN SECURITIES?  
    
        
A:   Generally, yes. Portfolio managers seek companies that meet their selection
     criteria regardless of country of organization or place of principal
business activity. Foreign securities are generally selected on a stock-by-stock
basis without regard to any defined allocation among countries or geographic
regions. However, certain factors such as expected levels of inflation,
government policies influencing business conditions, the outlook for currency
relationships, and prospects for economic growth among countries, regions or
geographic areas may warrant greater consideration in selecting foreign
securities. See "Additional Risk Factors" on pages 25-28.
    
 
   
Q:   WHAT IS A "SPECIAL SITUATION"?
    
 
   
A:   A special situation arises when a portfolio manager believes that the
     securities of an issuer will be recognized and appreciate in value due to a
specific development with respect to that issuer. Special situations may include
significant changes in a company's allocation of its existing capital, a
restructuring of assets, or a redirection of positive cash flows. For example,
issuers undergoing significant capital changes may include companies involved in
spin-offs, sales of divisions, mergers or acquisitions, companies emerging from
bankruptcy, or companies initiating large changes in their debt to equity ratio.
Companies that are redirecting cash flows may be reducing debt, repurchasing
shares or paying dividends. Special situations may also result from (i)
significant changes in industry structure through regulatory developments or
shifts in competition; (ii) a new or improved product, service, operation or
technological advance; (iii) changes in senior management; or (iv) significant
changes in cost structure. As noted above, Janus Special Situations Fund
emphasizes this type of investment.
    
 
Q:   WHAT IS THE MAIN RISK OF INVESTING
     IN A GROWTH FUND?

     
A:   Since growth funds usually invest heavily in common stocks, the fundamental
     risk is that the value of the stocks it holds might decrease. Stock values
may fluctuate in response to the activities of an individual company or in
response to general market and/or economic conditions. Historically, common
stocks have provided greater long-term returns and have entailed greater
short-term risks than other investment choices. Smaller or newer issuers
    
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    19
    
<PAGE>   
 
   
are more likely to realize more substantial growth as well as suffer more
significant losses than larger or more established issuers. Investments in such
companies can be both more volatile and more speculative. See "Additional Risk
Factors" on pages 25-28.
    
 
Q:   WHAT IS MEANT BY 
     "MARKET CAPITALIZATION"?

A:   Market capitalization is the most commonly used measure of the size and
     value of a company. It is computed by multiplying the current market price
of a share of the company's stock by the total number of its shares outstanding.
As noted previously, market capitalization is an important investment criteria
for Janus Enterprise Fund. Although the other Growth Funds offered by this
Prospectus do not emphasize companies of any particular size, Funds with a
larger asset base (e.g., Janus Fund) are more likely to invest in larger, more
established issuers.
 
Q:   HOW DOES A DIVERSIFIED FUND
     DIFFER FROM A NONDIVERSIFIED FUND?
   
A:   Diversification is a means of reducing risk by investing a fund's assets in
     a broad range of stocks or other securities. A "nondiversified" fund has
     the ability to take larger positions in a smaller number of issuers.
Because the appreciation or depreciation of a single stock may have a greater
impact on the NAV of a nondiversified fund, its share price can be expected to
fluctuate more than a comparable diversified fund. Janus Enterprise Fund, Janus
Olympus Fund, Janus Special Situations Fund, and Janus Twenty Fund are
nondiversified funds. See "General Portfolio Policies" on page 23.
    
 
Q:   HOW DO THE GROWTH FUNDS
     TRY TO REDUCE RISK?      
   
A:   Diversification of a Fund's assets reduces the effect of any single holding
     on its overall portfolio value. A Fund may also use futures, options and
other derivative instruments to protect its portfolio from movements in
securities prices and interest rates. The Funds may use a variety of currency
hedging techniques, including forward currency contracts, to manage exchange
rate risk. See "Additional Risk Factors" on pages 25-28. In addition, to the
extent that a Fund holds a larger cash position, it might not participate in
market declines to the same extent as if the Fund remained more fully invested
    
   
in common stocks.
    
 
   
 20   JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
- --------------------------------------------------------------------------------
 
COMBINATION FUNDS
 
<TABLE>
<S>                            <C>
Investment Objective:........  Growth of Capital; Some Emphasis on Income
Primary Holdings:............  Common Stocks and Income-Producing Securities
Shareholder's Investment
  Horizon:...................  Long-Term
</TABLE>
 
- --------------------------------------------------------------------------------
 
JANUS BALANCED FUND
The investment objective of this Fund is long-term capital growth, consistent
with preservation of capital and balanced by current income. It is a diversified
fund that, under normal circumstances, pursues its objective by investing 40-60%
of its assets in securities selected primarily for their growth potential and
40-60% of its assets in securities selected primarily for their income
potential. This Fund normally invests at least 25% of its assets in fixed-income
senior securities, which include debt securities and preferred stocks.
 
JANUS EQUITY INCOME FUND
The investment objective of this Fund is current income and long-term growth of
capital. It is a diversified fund that pursues its objective by normally
investing at least 65% of its invested assets in income-producing equity
securities. Equity securities include common stocks, preferred stocks, warrants
and securities convertible into common or preferred stocks. Growth potential is
a significant investment consideration and the Fund may hold securities selected
solely for their growth potential.
 
JANUS GROWTH AND INCOME FUND
   
The investment objective of this Fund is long-term capital growth and current
income. It is a diversified fund that, under normal circumstances, pursues its
objective by investing up to 75% of its assets in equity securities selected
primarily for their growth potential and at least 25% of its assets in
securities that the portfolio manager believes have income potential. The Fund
normally emphasizes the growth component. However, in unusual circumstances
(such as those described under "Cash Position" on page 23), this Fund may reduce
the growth component of its portfolio to 25% of its assets.
    
 
COMBINATION FUNDS
   
All of the Combination Funds may invest in a combination of common stocks,
preferred stocks, convertible securities, debt securities and other fixed-income
securities. The Combination Funds may invest in the types of investments
previously described under "Growth Funds" on page 18. Although each of the
Combination Funds places some emphasis on the income objective, investors should
keep in mind that the Combination Funds are not designed to produce a consistent
level of income.
    
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    21
    
<PAGE>   
 
THE FOLLOWING QUESTIONS ARE DESIGNED TO HELP YOU BETTER UNDERSTAND AN INVESTMENT
IN THE JANUS COMBINATION FUNDS.
 
Q:   HOW DO THE COMBINATION FUNDS 
     DIFFER FROM EACH OTHER? 
   
A:   Janus Growth and Income Fund places a greater emphasis on aggressive growth
     stocks and may derive a greater portion of its income from dividend-paying
common stocks. Because of these factors, its share price can be expected to
fluctuate more than the other Combination Funds. Janus Equity Income Fund
emphasizes investments in dividend-paying common stocks and other equity
securities characterized by relatively greater price stability, and thus may be
expected to be less volatile than Janus Growth and Income Fund, as discussed in
more detail below. Janus Balanced Fund places a greater emphasis on the income
component of its portfolio and invests to a greater degree in debt securities
and preferred stock. As a result it is the least volatile of the Combination
Funds.
    
 
Q:   HOW DOES JANUS EQUITY INCOME 
     FUND TRY TO LIMIT PORTFOLIO VOLATILITY?
A:   Janus Equity Income Fund seeks to provide a lower level of volatility than
     the stock market at large, as measured by the S&P 500. The lower volatility
sought by this Fund is expected to result primarily from investments in
dividend-paying common stocks and other equity securities characterized by
relatively greater price stability. The greater price stability sought by Janus
Equity Income Fund may be characteristic of companies that generate above
average positive cash flows. A company may use positive cash flows for a number
of purposes including commencing or increasing dividend payments, repurchasing
its own stock or retiring outstanding debt. The portfolio manager also considers
growth potential in selecting this Fund's securities and may hold securities
selected solely for their growth potential.
 
Q:   HOW ARE EQUITY SECURITIES SELECTED? 
   
A:   The growth component of Janus Balanced Fund and Janus Growth and Income
     Fund is expected to consist primarily of common stocks and Janus Equity
Income Fund invests substantially all of its assets in common stocks. The
selection criteria for common stocks are described on page 18. Because income is
a part of the investment objective of the Combination Funds, a portfolio manager
may consider dividend-paying characteristics to a greater degree in selecting
equity securities for these Funds. The Combination Funds may also find
opportunities for capital growth from debt securities because of anticipated
changes in interest rates, credit standing, currency relationships or other
factors.
    
 
   
 22   JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
Q:   HOW ARE ASSETS ALLOCATED BETWEEN THE GROWTH AND INCOME
     COMPONENT OF JANUS BALANCED FUND'S AND JANUS GROWTH AND INCOME FUND'S
     PORTFOLIOS?
   
A:   Janus Balanced Fund and Janus Growth and Income Fund shift assets between
     the growth and income components of their portfolios based on the portfolio
managers' analysis of relevant market, financial and economic conditions. If a
portfolio manager believes that growth securities will provide better returns
than the yields then available or expected on income-producing securities, then
that Fund will place a greater emphasis on the growth component.
    
 
Q:   WHAT TYPES OF SECURITIES MAKE UP THE INCOME COMPONENT
     OF JANUS BALANCED FUND'S AND JANUS GROWTH AND INCOME FUND'S PORTFOLIOS?
   
A:   The income component of Janus Balanced Fund and Janus Growth and Income
     Fund will consist of securities that the portfolio managers believe have
income potential. Such securities may include equity securities, convertible
securities and all types of debt securities. Equity securities may be included
in the income component of a Fund if they currently pay dividends or a portfolio
manager believes they have the potential for either increasing their dividends
or commencing dividends, if none are currently paid.
    
 
GENERAL PORTFOLIO POLICIES
Unless otherwise stated, each of the following policies applies to all of the
Funds. The percentage limitations included in these policies and elsewhere in
this Prospectus apply at the time of purchase of the security. For example, if a
Fund exceeds a limit as a result of market fluctuations or the sale of other
securities, it will not be required to dispose of any securities.
 
CASH POSITION
   
When a Fund's portfolio manager believes that market conditions are not
favorable for profitable investing or when the portfolio manager is otherwise
unable to locate favorable investment opportunities, a Fund's investments may be
hedged to a greater degree and/or its cash or similar investments may increase.
In other words, the Funds do not always stay fully invested in stocks and bonds.
Cash or similar investments are a residual - they represent the assets that
remain after a portfolio manager has committed available assets to desirable
investment opportunities. Partly because the portfolio managers act
independently of each other, the cash positions of the Funds may vary
significantly. Larger hedged positions and/or larger cash positions may serve as
a means of preserving capital in unfavorable market conditions.
    
 
   
Securities that the Funds may invest in as a means of receiving a return on idle
cash include high-grade commercial paper, certificates of deposit, repurchase
agreements or other short-term debt obligations. The Funds may also invest in
money market funds (including funds managed by Janus Capital). When a Fund is
hedged or its investments in cash or similar investments increase, it may not
participate in stock or bond market
    
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    23
    
<PAGE>   
 
   
advances or declines to the same extent that it would if the Fund was not hedged
or remained more fully invested in stocks or bonds.
    
 
DIVERSIFICATION
   
The Investment Company Act of 1940 (the "1940 Act") classifies investment
companies as either diversified or nondiversified. All of the Funds (except
Janus Enterprise Fund, Janus Olympus Fund, Janus Special Situations Fund and
Janus Twenty Fund) qualify as diversified funds under the 1940 Act. The Funds
are subject to the following diversification requirements:
    
 
- - As a fundamental policy, no Fund may own more than 10% of the outstanding
  voting shares of any issuer.
 
   
- - As a fundamental policy, with respect to 50% of the total assets of Janus
  Enterprise Fund, Janus Olympus Fund, Janus Special Situations Fund and Janus
  Twenty Fund and 75% of the total assets of the other Funds, no Fund will
  purchase a security of any issuer (other than cash items and U.S. government
  securities, as defined in the 1940 Act) if such purchase would cause a Fund's
  holdings of that issuer to amount to more than 5% of that Fund's total assets.
    
 
- - No Fund will invest more than 25% of its total assets in a single issuer
  (other than U.S. government securities).
 
   
- - Janus Enterprise Fund, Janus Olympus Fund, Janus Special Situations Fund and
  Janus Twenty Fund reserve the right to become diversified funds by limiting
  the investments in which more than 5% of their total assets are invested.
    
 
INDUSTRY CONCENTRATION
As a fundamental policy, no Fund will invest 25% or more of its total assets in
any particular industry (excluding U.S. government securities).
 
PORTFOLIO TURNOVER
Each Fund generally intends to purchase securities for long-term investment
rather than short-term gains. However, short-term transactions may result from
liquidity needs, securities having reached a price or yield objective, changes
in interest rates or the credit standing of an issuer, or by reason of economic
or other developments not foreseen at the time of the initial investment
decision. Changes are made in a Fund's portfolio whenever its portfolio manager
believes such changes are desirable. Portfolio turnover rates are generally not
a factor in making buy and sell decisions.
 
   
To a limited extent, a Fund may purchase securities in anticipation of
relatively short-term price gains. A Fund may also sell one security and
simultaneously purchase the same or a comparable security to take advantage of
short-term differentials in bond yields or securities prices. Increased
portfolio turnover may result in higher costs for brokerage commissions, dealer
mark-ups and other transaction costs and may also result in taxable capital
gains.
    
 
ILLIQUID INVESTMENTS
   
Each Fund may invest up to 15% of its net assets in illiquid investments,
including restricted securities or private placements that are not deemed to be
liquid by Janus Capital. If illiquid securities exceed 15% of a Fund's net
assets after the time of
    
 
   
 24   JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
   
purchase, the Fund will take steps to reduce in an orderly fashion its holdings
of illiquid securities. An illiquid investment is a security or other position
that cannot be disposed of quickly in the normal course of business. Some
securities cannot be sold to the U.S. public because of their terms or because
of SEC regulations. Janus Capital will follow guidelines established by the
Funds' Trustees in making liquidity determinations for Rule 144A securities and
certain other securities, including privately placed commercial paper and
municipal lease obligations.
    
 
BORROWING AND LENDING
Each Fund may borrow money and lend securities or other assets, as follows:
 
- - Each Fund may borrow money for temporary or emergency purposes in amounts up
  to 25% of its total assets.
 
   
- - Each Fund may mortgage or pledge securities as collateral for borrowings in
  amounts up to 15% of its net assets.
    
 
- - As a fundamental policy, each Fund may lend securities or other assets if, as
  a result, no more than 25% of its total assets would be lent to other parties.
 
   
Under the terms of an exemptive order received from the SEC, each of the Funds
may borrow money from or lend money to each other and other funds that permit
such transactions and for which Janus Capital serves as investment adviser. All
such borrowing and lending will be subject to the above percentage limits.
    
 
ADDITIONAL RISK FACTORS
FOREIGN SECURITIES
Investments in foreign securities, including those of foreign governments, may
involve greater risks than investing in comparable domestic securities.
Securities of some foreign companies and governments may be traded in the United
States, but many foreign securities are traded primarily in foreign markets. The
risks of foreign investing include:
 
- - CURRENCY RISK. A Fund may buy the local currency when it buys a foreign
  currency denominated security and sell the local currency when it sells the
  security. As long as a Fund holds a foreign security, its value will be
  affected by the value of the local currency relative to the U.S. dollar. When
  a Fund sells a foreign denominated security, its value may be worth less in
  U.S. dollars even though the security increases in value in its home country.
  U.S. dollar denominated securities of foreign issuers may also be affected by
  currency risk.
 
- - POLITICAL AND ECONOMIC RISK. Foreign investments may be subject to heightened
  political and economic risks, particularly in underdeveloped or developing
  countries which may have relatively unstable governments and economies based
  on only a few industries. In some countries, there is the risk that the
  government may take over the assets or operations of a company or that the
  government may impose taxes or limits on the removal of a Fund's assets from
  that country. The Funds may invest in emerging market countries. Emerging
  market countries involve greater risks such as immature economic structures,
  national policies restricting investments by foreigners, and different legal
  systems.
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    25
    
<PAGE>   
 
- - REGULATORY RISK. There may be less government supervision of foreign markets.
  Foreign issuers may not be subject to the uniform accounting, auditing and
  financial reporting standards and practices applicable to domestic issuers.
  There may be less publicly available information about foreign issuers than
  domestic issuers.
 
- - MARKET RISK. Foreign securities markets, particularly those of underdeveloped
  or developing countries, may be less liquid and more volatile than domestic
  markets. Certain markets may require payment for securities before delivery
  and delays may be encountered in settling securities transactions. In some
  foreign markets, there may not be protection against failure by other parties
  to complete transactions. There may be limited legal recourse against an
  issuer in the event of a default on a debt instrument.
 
- - TRANSACTION COSTS. Transaction costs of buying and selling foreign securities,
  including brokerage, tax and custody costs, are generally higher than those
  involved in domestic transactions.
 
Foreign securities purchased indirectly (e.g., depositary receipts) are subject
to many of the above risks, including currency risk, because their values depend
on the performance of a foreign security denominated in its home currency.
 
INVESTMENTS IN SMALLER COMPANIES
Smaller or newer companies may suffer more significant losses as well as realize
more substantial growth than larger or more established issuers. Smaller or
newer companies may lack depth of management, they may be unable to generate
funds necessary for growth or potential development, or they may be developing
or marketing new products or services for which markets are not yet established
and may never become established. In addition, such companies may be
insignificant factors in their industries and may become subject to intense
competition from larger or more established companies. Securities of smaller or
newer companies may have more limited trading markets than the markets for
securities of larger or more established issuers, and may be subject to wider
price fluctuations. Investments in such companies tend to be more volatile and
somewhat more speculative.
 
FUTURES, OPTIONS AND OTHER DERIVATIVE INSTRUMENTS
Each Fund may enter into futures contracts on securities, financial indices and
foreign currencies and options on such contracts ("futures contracts") and may
invest in options on securities, financial indices and foreign currencies
("options"), forward contracts and interest rate swaps and swap-related products
(collectively "derivative instruments"). The Funds intend to use most derivative
instruments primarily to hedge the value of their portfolios against potential
adverse movements in securities prices, foreign currency markets or interest
rates. To a limited extent, the Funds may also use derivative instruments for
non-hedging purposes such as seeking to increase a Fund's income or otherwise
seeking to enhance return. Please refer to Appendix A to this Prospectus and the
SAI for a more detailed discussion of these instruments.
 
The use of derivative instruments exposes the Funds to additional investment
risks and transaction costs. Risks inherent in the use of derivative instruments
include:
 
- - the risk that interest rates, securities prices and currency markets will not
  move in the direction that a portfolio manager anticipates;
 
   
 26   JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
- - imperfect correlation between the price of derivative instruments and
  movements in the prices of the securities, interest rates or currencies being
  hedged;
 
- - the fact that skills needed to use these strategies are different from those
  needed to select portfolio securities;
 
- - inability to close out certain hedged positions to avoid adverse tax
  consequences;
 
- - the possible absence of a liquid secondary market for any particular
  instrument and possible exchange-imposed price fluctuation limits, either of
  which may make it difficult or impossible to close out a position when
  desired;
 
- - leverage risk, that is, the risk that adverse price movements in an instrument
  can result in a loss substantially greater than a Fund's initial investment in
  that instrument (in some cases, the potential loss is unlimited); and
 
- - particularly in the case of privately-negotiated instruments, the risk that
  the counterparty will fail to perform its obligations, which could leave a
  Fund worse off than if it had not entered into the position.
 
Although the Funds believe the use of derivative instruments will benefit the
Funds, a Fund's performance could be worse than if the Fund had not used such
instruments if a portfolio manager's judgement proves incorrect.
 
When a Fund invests in a derivative instrument, it may be required to segregate
cash and other liquid assets or certain portfolio securities with its custodian
to "cover" the Fund's position. Assets segregated or set aside generally may not
be disposed of so long as the Fund maintains the positions requiring segregation
or cover. Segregating assets could diminish the Fund's return due to the
opportunity losses of foregoing other potential investments with the segregated
assets.
 
HIGH-YIELD/HIGH-RISK SECURITIES
   
High-yield/high-risk securities (or "junk" bonds) are debt securities rated
below investment grade by the primary rating agencies such as Standard & Poor's
Ratings Services ("Standard & Poor's") and Moody's Investors Service, Inc.
("Moody's").
    
 
The value of lower quality securities generally is more dependent on the ability
of the issuer to meet interest and principal payments (i.e., credit risk) than
is the case for higher quality securities. Conversely, the value of higher
quality securities may be more sensitive to interest rate movements than lower
quality securities. Issuers of high-yield securities may not be as strong
financially as those issuing bonds with higher credit ratings. Investments in
such companies are considered to be more speculative than higher quality
investments.
 
Issuers of high-yield securities are more vulnerable to real or perceived
economic changes (for instance, an economic downturn or prolonged period of
rising interest rates), political changes or adverse developments specific to
the issuer. The market for lower quality securities is generally less liquid
than the market for higher quality securities. Adverse publicity and investor
perceptions as well as new or proposed laws may also have a greater negative
impact on the market for lower quality securities.
 
Please refer to the SAI for a description of bond rating categories.
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    27
    
<PAGE>   
 
SHORT SALES
   
Each Fund may engage in "short sales against the box." This technique involves
selling either a security that a Fund owns, or a security equivalent in kind and
amount to the security sold short that the Fund has the right to obtain, for
delivery at a specified date in the future. A Fund may enter into a short sale
against the box to hedge against anticipated declines in the market price of
portfolio securities. If the value of the securities sold short increases prior
to the scheduled delivery date, a Fund loses the opportunity to participate in
the gain.
    
 
SPECIAL SITUATIONS
Each Fund may invest in "special situations" from time to time. A special
situation arises when, in the opinion of a Fund's portfolio manager, the
securities of a particular issuer will be recognized and appreciate in value due
to a specific development with respect to that issuer. Developments creating a
special situation might include, among others, a new product or process, a
technological breakthrough, a management change or other extraordinary corporate
event, or differences in market supply of and demand for the security.
Investment in special situations may carry an additional risk of loss in the
event that the anticipated development does not occur or does not attract the
expected attention.
 
See Appendix A for risks associated with certain other investments.
 
   
 28   JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
                              SHAREHOLDER'S MANUAL
 
This section will help you become familiar with the different types of accounts
you can establish with Janus. This section also explains in detail the wide
array of services and features you can establish on your account. These services
and features may be modified or discontinued without shareholder approval or
prior notice.
 
    MINIMUM INVESTMENTS*
 
   
<TABLE>
      <S>                                                  <C>
      To open a new account..............................   $2,500
      To open a new retirement, education, or UGMA/UTMA
        account..........................................   $  500
      To open a new account with an Automatic Investment
        Program..........................................   $  500**
      To add to any type of an account...................   $  100+
</TABLE>
    
 
     * THE FUNDS RESERVE THE RIGHT TO CHANGE THE AMOUNT OF THESE MINIMUMS
       FROM TIME TO TIME OR TO WAIVE THEM IN WHOLE OR IN PART FOR CERTAIN
       TYPES OF ACCOUNTS.
   
    ** AN AUTOMATIC INVESTMENT PROGRAM REQUIRES A $100 MINIMUM AUTOMATIC
       INVESTMENT PER MONTH UNTIL THE ACCOUNT BALANCE REACHES $2,500.
    
   
     + THE MINIMUM SUBSEQUENT INVESTMENT FOR IRA OR UGMA/UTMA ACCOUNTS IS
       $50.
    
 
HOW TO GET IN TOUCH WITH JANUS
   
If you have any questions while reading this Prospectus, please call one of our
Investor Service Representatives at 1-800-525-3713 Monday-Friday: 8:00 a.m.-8:00
p.m., and Saturday: 10:00 a.m.-4:00 p.m., New York time. The Quick Address and
Telephone Reference below includes other ways to get in touch with Janus.
    
 
   
   QUICK ADDRESS AND TELEPHONE REFERENCE
    
 
   
<TABLE>
    <S>                               <C>
    MAILING ADDRESS                   JANUS XPRESS
    Janus                             LINE      1-888-979-7737
    P.O. Box 173375                   For 24-hour access to
    Denver, CO 80217-3375             account and fund
                                      information, exchanges and
    FOR OVERNIGHT CARRIER             purchases, automated daily
    Janus                             quotes on fund share
    Suite 101                         prices, yields and total
    3773 Cherry Creek North           returns.
      Drive                           TDD                  1-800-525-0056
    Denver, CO 80209-3811             A telecommunications device
                                      for our hearing- and
    JANUS INTERNET ADDRESS            speech-impaired
    http://www.Janus.com              shareholders.
                                      JANUS LITERATURE
                                      LINE    1-800-525-8983
                                      To request a prospectus,
                                      shareholder reports or
                                      marketing materials.
</TABLE>
    
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    29
    
<PAGE>   
 
TYPES OF ACCOUNT OWNERSHIP
   
If you are investing in the Funds for the first time, you will need to establish
an account. You can establish the following types of accounts by completing a
New Account Application. To request an application, call 1-800-525-3713.
    
 
- - INDIVIDUAL OR JOINT OWNERSHIP. Individual accounts are owned by one person.
  Joint accounts have two or more owners.
 
- - A GIFT OR TRANSFER TO MINOR (UGMA OR UTMA). An UGMA/UTMA account is a
  custodial account managed for the benefit of a minor. To open an UGMA or UTMA
  account, you must include the minor's Social Security number on the
  application.
 
- - TRUST. An established trust can open an account. The names of each trustee,
  the name of the trust and the date of the trust agreement must be included on
  the application.
 
- - BUSINESS ACCOUNTS. Corporations and partnerships may also open an account. The
  application must be signed by an authorized officer of the corporation or a
  general partner of the partnership.
 
   
TAX-DEFERRED ACCOUNTS
    
   
If you are eligible, you may set up one or more tax-deferred accounts. A
tax-deferred account allows you to shelter your investment income and capital
gains from current income taxes. A contribution to certain of these plans may
also be tax deductible. Tax deferred accounts include retirement plans and the
Education IRA. Distributions from these plans are generally subject to income
tax and may be subject to an additional tax if withdrawn prior to age 59 1/2 or
used for a nonqualifying purpose. Investors should consult their tax advisor or
legal counsel before selecting a tax-deferred account.
    
 
   
Investors Fiduciary Trust Company serves as custodian for the tax-deferred
accounts offered by the Funds. There is an annual $12 fee per account to
maintain your tax-deferred account. The maximum annual fee is $24 per taxpayer
identification number. You may pay the fee by check or have it automatically
deducted from your account (usually in December). The Funds reserve the right to
change the amount of this fee or to waive it in whole or in part for certain
types of accounts.
    
 
   
The following plans require a special application. For an application and more
details about our Retirement Plans, call 1-800-525-3713.
    
 
   
- - REGULAR AND ROTH INDIVIDUAL RETIREMENT ACCOUNTS ("IRAS"): Both types of IRAs
  allow most individuals with earned income to contribute up to the lesser of
  $2,000 ($4,000 for most married couples) or 100% of compensation annually.
  Please refer to the Janus IRA booklet for complete information regarding the
  different types of IRAs.
    
 
   
- - EDUCATION IRA: This plan allows individuals, subject to certain income
  limitations, to contribute up to $500 annually on behalf of any child under
  the age of 18. Please refer to the Janus IRA booklet for complete information
  regarding the Education IRA.
    
 
- - SIMPLIFIED EMPLOYEE PENSION PLAN ("SEP"): This plan allows small business
  owners (including sole proprietors) to make tax-deductible contributions for
 
   
 30   JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
  themselves and any eligible employee(s). A SEP requires an IRA (a SEP-IRA) to
  be set up for each SEP participant.
 
- - PROFIT SHARING OR MONEY PURCHASE PENSION PLAN: These plans are open to
  corporations, partnerships and sole proprietors to benefit their employees and
  themselves.
 
- - SECTION 403(B)(7) PLAN: Employees of educational organizations or other
  qualifying, tax-exempt organizations may be eligible to participate in a
  Section 403(b)(7) Plan.
 
HOW TO OPEN YOUR JANUS ACCOUNT
   
Complete and sign the appropriate application. Please be sure to provide your
Social Security or taxpayer identification number on the application and make
your check payable to Janus. The Funds are available only to U.S. citizens or
residents, and your application will be returned if you do not meet these
criteria. Send all items to one of the following addresses:
    
 
   
For Overnight Carrier
    
- --------------------
Janus
Suite 101
3773 Cherry Creek North Drive
Denver, CO 80209-3811
 
   
For All Other Inquiries
    
- ---------------------
   
Janus
    
   
P.O. Box 173375
    
   
Denver, CO 80217-3375
    
 
INVESTOR SERVICE CENTERS
   
Janus offers two Investor Service Centers for those individuals who would like
to conduct their investing in person. Our representatives will be happy to
assist you at either of the following locations: Monday-Friday 7:00 a.m. to 6:00
p.m. Mountain time and Saturday 9:00 a.m. to 1:00 p.m. Mountain time.
    
 
100 Fillmore Street, Suite 100
Denver, CO 80206
 
3773 Cherry Creek North Drive, Suite 101
Denver, CO 80209
 
HOW TO PURCHASE SHARES
PAYING FOR SHARES
When you purchase shares, your request will be processed at the next NAV
calculated after your order is received and accepted. Please note the following:
 
- - Cash, credit cards, third party checks and credit card checks will not be
  accepted.
 
- - All purchases must be made in U.S. dollars.
 
- - Checks must be drawn on U.S. banks and made payable to Janus.
 
- - If a check does not clear your bank, the Funds reserve the right to cancel the
  purchase.
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    31
    
<PAGE>   
 
- - If the Funds are unable to debit your predesignated bank account on the day of
  purchase, they may make additional attempts or cancel the purchase.
 
- - The Funds reserve the right to reject any specific purchase request.
 
If your purchase is cancelled, you will be responsible for any losses or fees
imposed by your bank and losses that may be incurred as a result of any decline
in the value of the cancelled purchase. The Funds (or their agents) have the
authority to redeem shares in your account(s) to cover any losses due to
fluctuations in share price. Any profit on such cancellation will accrue to the
Fund.
 
   
ONCE YOU HAVE OPENED YOUR JANUS ACCOUNT, THE MINIMUM AMOUNT FOR AN ADDITIONAL
INVESTMENT IS $100 ($50 FOR IRAS OR UGMA/UTMA ACCOUNTS). You may add to your
account at any time through any of the following options:
    
 
BY MAIL
Complete the remittance slip attached at the bottom of your confirmation
statement. If you are making a purchase into a retirement account, please
indicate whether the purchase is a rollover or a current or prior year
contribution. Send your check and remittance slip or written instructions to one
of the addresses listed previously. You may also request a booklet of remittance
slips for non-retirement accounts.
 
BY TELEPHONE
   
This service allows you to purchase additional shares quickly and conveniently
through an electronic transfer of money. To purchase shares by telephone, call
an Investor Service Representative at 1-800-525-3713 during normal business
hours or call the Janus Xpress Line, 1-888-979-7737, for access to this option
24 hours a day. When you make an additional purchase by telephone, Janus will
automatically debit your predesignated bank account for the desired amount. To
establish the telephone purchase option on your new account, complete the
"Telephone Purchase of Shares Option" section on the application and attach a
"voided" check or deposit slip from your bank account. If your account is
already established, call 1-800-525-3713 to request the appropriate form. This
option will become effective ten business days after the form is received.
    
 
BY WIRE
Purchases may also be made by wiring money from your bank account to your Janus
account. Call 1-800-525-3713 to receive wiring instructions.
 
AUTOMATIC INVESTMENT PROGRAMS
   
Janus offers several automatic investment programs to help you achieve your
financial goals as simply and conveniently as possible. You may open a new
account with a $500 initial purchase and $100 automatic subsequent investments.
    
 
- - AUTOMATIC MONTHLY INVESTMENT PROGRAM
  You select the day each month that your money ($100 minimum) will be
  electronically transferred from your bank account to your Fund account. To
  establish this option, complete the "Automatic Monthly Investment Program"
  section on the application and attach a "voided" check or deposit slip from
  your bank account. If your Fund account is already established, call
  1-800-525-3713 to request the appropriate form.
 
   
 32   JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
- - PAYROLL DEDUCTION
  If your employer can initiate an automatic payroll deduction, you may have all
  or a portion of your paycheck ($100 minimum) invested directly into your Fund
  account. To obtain information on establishing this option, call
  1-800-525-3713.
 
- - SYSTEMATIC EXCHANGE
  With a Systematic Exchange you determine the amount of money ($100 minimum)
  you would like automatically exchanged from one Janus account to another on
  any day of the month. For more information on how to establish this option,
  call 1-800-525-3713.
 
HOW TO EXCHANGE SHARES
On any business day, you may exchange all or a portion of your shares into any
other available Janus fund.
 
IN WRITING
   
To request an exchange in writing, please follow the instructions for written
requests on page 35.
    
 
BY TELEPHONE
   
All accounts are automatically eligible for the telephone exchange option. To
exchange shares by telephone, call an Investor Service Representative at
1-800-525-3713 during normal business hours or call the Janus Xpress Line,
1-888-979-7737, for access to this option 24 hours a day.
    
 
BY SYSTEMATIC EXCHANGE
   
As noted above, you may establish a Systematic Exchange for as little as $100
per month on established accounts. You may establish a new account with a $500
initial purchase and subsequent $100 systematic exchanges. If the balance in the
account you are exchanging from falls below the systematic exchange amount, all
remaining shares will be exchanged and the program will be discontinued.
    
 
EXCHANGE POLICIES
- - Except for Systematic Exchanges, new accounts established by exchange must be
  opened with $2,500 or the total account value if the value of the account you
  are exchanging from is less than $2,500.
 
- - Exchanges between existing accounts must meet the $100 subsequent investment
  requirement.
 
- - You may make four exchanges out of each Fund during a calendar year (exclusive
  of Systematic Exchanges) free of charge.
 
- - Exchanges between accounts will be accepted only if the registrations are
  identical.
 
- - If the shares you are exchanging are held in certificate form, you must return
  the certificate to your Fund prior to making any exchanges.
 
- - Be sure that you read the prospectus for the fund into which you are
  exchanging.
 
- - The Funds reserve the right to reject any exchange request and to modify or
  terminate the exchange privilege at any time. For example, the Funds may
  reject
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    33
    
<PAGE>   
 
  exchanges from accounts engaged in excessive trading (including market timing
  transactions) that are believed to be detrimental to the Funds.
 
- - An exchange represents the sale of shares from one fund and the purchase of
  shares of another fund, which may produce a taxable gain or loss in a non-tax
  deferred account.
 
HOW TO REDEEM SHARES
On any business day, you may redeem all or a portion of your shares. If the
shares are held in certificate form, the certificate must be returned with or
before your redemption request. Your transaction will be processed at the next
NAV calculated after your order is received and accepted.
 
IN WRITING
   
To request a redemption in writing, please follow the instructions for written
requests on page 35.
    
 
BY TELEPHONE
   
Most accounts have the telephone redemption option, unless this option was
specifically declined on the application or in writing. This option enables you
to request redemptions daily from your account by calling 1-800-525-3713 by the
close of the regular trading session of the New York Stock Exchange ("NYSE")
normally 4:00 p.m. New York time. You may also use Janus Xpress Line,
1-888-979-7737, for access to this option 24 hours a day. Redemption requests
received through Janus Xpress Line will be processed at the NAV next calculated
after receipt and acceptance of the request. (There is a daily limit of $100,000
per account for redemptions payable by check).
    
 
SYSTEMATIC REDEMPTION OPTION
Systematic Redemption Options allow you to redeem a specific dollar amount from
your account on a regular basis. For more information or to request the
appropriate form, please call 1-800-525-3713.
 
PAYMENT OF REDEMPTION PROCEEDS
- - BY CHECK
  Redemption proceeds will be sent to the shareholder(s) of record at the
  address of record within seven days after receipt of a valid redemption
  request.
 
   
- - BY ELECTRONIC TRANSFER
    
   
  If you have established the electronic redemption option, your redemption
  proceeds can be electronically transferred to your predesignated bank account
  on the next bank business day after receipt of your redemption request (wire
  transfer) or the second bank business day after receipt of your redemption
  request (ACH transfer). Wire transfers will be charged an $8 fee per wire and
  your bank may charge an additional fee to receive the wire. ACH transfers are
  made free of charge. Wire redemptions are not available for retirement
  accounts.
    
 
   
  If you would like to establish the electronic redemption option on an existing
  account, please call 1-800-525-3713 to request the appropriate form.
    
 
   
IF THE SHARES BEING REDEEMED WERE PURCHASED BY CHECK, TELEPHONE OR THROUGH THE
AUTOMATIC MONTHLY INVESTMENT PROGRAM, THE FUNDS MAY DELAY
    
 
   
 34   JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
   
THE PAYMENT OF YOUR REDEMPTION PROCEEDS FOR UP TO 15 DAYS FROM THE DAY OF
PURCHASE TO ALLOW THE PURCHASE TO CLEAR. Unless you provide alternate
instructions, your proceeds will be invested in Janus Money Market
Fund - Investor Shares during the 15 day hold period.
    
 
WRITTEN INSTRUCTIONS
   
To redeem or exchange all or part of your shares in writing, your request should
be sent to one of the addresses listed on page 31 and must include the following
information:
    
 
- - the name of the Fund(s)
 
- - the account number(s)
 
- - the amount of money or number of shares being redeemed
 
- - the name(s) on the account
 
- - the signature(s) of all registered account owners
 
- - your daytime telephone number
 
SIGNATURE REQUIREMENTS BASED ON ACCOUNT TYPE
- - Individual, Joint Tenants, Tenants in Common: Written instructions must be
 --------------------------------------------
  signed by each shareholder, exactly as the names appear in the account
  registration.
 
- - UGMA or UTMA: Written instructions must be signed by the custodian in
 ------------------
  his/her capacity as it appears in the account registration.
 
- - Sole Proprietor, General Partner: Written instructions must be signed by an
 --------------------------------
  authorized individual in his/her capacity as it appears on the account
  registration.
 
- - Corporation, Association: Written instructions must be signed by the
 ------------------------
  person(s) authorized to act on the account. In addition, a certified copy of 
  the corporate resolution authorizing the signer to act must accompany the 
  request.

- - Trust: Written instructions must be signed by the trustee(s). If the name of
 ------
  the current trustee(s) does not appear in the account registration, a
  certificate of incumbency dated within 60 days must also be submitted.
 
- - IRA: Written instructions must be signed by the account owner. If you do
 -----
  not want federal income tax withheld from your redemption, you must state that
  you elect not to have such withholding apply. In addition, your instructions
  must state whether the distribution is normal (after age 59 1/2) or premature
  (before age 59 1/2) and, if premature, whether any exceptions such as death or
  disability apply with regard to the 10% additional tax on early distributions.
 
   
SIGNATURE GUARANTEE
    
In addition to the signature requirements, a signature guarantee is also
required if any of the following is applicable:
 
   
- - You request a redemption that exceeds $100,000.
    
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    35
    
<PAGE>   
 
- - You would like the check made payable to anyone other than the shareholder(s)
  of record.
 
- - You would like the check mailed to an address which has been changed within 10
  days of the redemption request.
 
- - You would like the check mailed to an address other than the address of
  record.
 
THE FUNDS RESERVE THE RIGHT TO REQUIRE A SIGNATURE GUARANTEE UNDER OTHER
CIRCUMSTANCES OR TO REJECT OR DELAY A REDEMPTION ON CERTAIN LEGAL GROUNDS. FOR
MORE INFORMATION PERTAINING TO SIGNATURE GUARANTEES, PLEASE CALL 1-800-525-3713.
 
HOW TO OBTAIN A SIGNATURE GUARANTEE
A signature guarantee assures that a signature is genuine. The signature
guarantee protects shareholders from unauthorized account transfers. The
following financial institutions may guarantee signatures: banks, savings and
loan associations, trust companies, credit unions, broker-dealers, and member
firms of a national securities exchange. Call your financial institution to see
if they have the ability to guarantee a signature. A signature guarantee may not
be provided by a notary public.
 
If you live outside the United States, a foreign bank properly authorized to do
business in your country of residence or a U.S. consulate may be able to
authenticate your signature.
 
   
PRICING OF FUND SHARES
    
   
All purchases, redemptions and exchanges will be processed at the NAV next
calculated after your request is received and approved by a Fund (or its
designated agent). A Fund's NAV is calculated at the close of the regular
trading session of the NYSE (normally 4:00 p.m. New York time) each day that the
NYSE is open. In order to receive a day's price, your order must be received by
the close of the regular trading session of the NYSE. Securities are valued at
market value or, if a market quotation is not readily available, at their fair
value determined in good faith under procedures established by and under the
supervision of the Trustees. Short-term instruments maturing within 60 days are
valued at amortized cost, which approximates market value. See the SAI for more
detailed information.
    
 
SHAREHOLDER SERVICES AND ACCOUNT POLICIES
   
JANUS XPRESS LINE(TM)
    
   
Janus Xpress Line, our electronic telephone service, offers you 24-hour access
by TouchTone(TM) telephone to obtain information on account balances, Fund
performance or dividends. You can also make exchanges, purchases, redemptions
and electronic transfers in existing accounts, request literature about any
Janus fund, or order duplicate statements. Janus Xpress Line is accessed by
calling 1-888-979-7737. Calls are limited to five minutes.
    
 
JANUS WEB SITE
   
Janus maintains a Web site located at http://www.Janus.com. You can access
information such as your account balance and the Funds' NAVs through the Web
site. In addition, you may request and/or download a prospectus for any Janus
fund.
    
 
   
 36   JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
ACCOUNT MINIMUMS
   
Minimum account sizes are noted on page 29. An account established on or before
February 18, 1996 is required to meet the minimum balances in effect when the
account was established ($1,000 for regular accounts and $250 for retirement and
UGMA/UTMA accounts). An active Automatic Monthly Investment (AMI) on any such
account exempted it from any minimum initial investment requirement and
continues to do so. In addition, an active AMI on these accounts may continue at
$50 per month, provided there is no interruption in the AMI program. All other
subsequent investments must meet the $100 required minimum.
    
 
   
Due to the proportionately higher costs of maintaining small accounts, Janus
reserves the right to deduct a $10 minimum balance fee (or the value of the
account if less than $10) from accounts with values below the minimums described
on page 29 or to close such accounts. This policy will apply to accounts
participating in the Automatic Monthly Investment Program only if your account
balance does not reach the required minimum initial investment or falls below
such minimum and you have discontinued monthly investments. This policy does not
apply to accounts that fall below the minimums solely as a result of market
value fluctuations. It is expected that, for purposes of this policy, accounts
will be valued in September, and the $10 fee will be assessed on the second
Friday of September of each year. You will receive notice before we charge the
$10 fee or close your account so that you may increase your account balance to
the required minimum.
    
 
TRANSACTIONS THROUGH PROCESSING ORGANIZATIONS
You may purchase or sell Fund shares through a broker-dealer, bank or other
financial institution, or an organization that provides recordkeeping and
consulting services to 401(k) plans or other employee benefit plans (a
"Processing Organization"). Processing Organizations may charge you a fee for
this service and may require different minimum initial and subsequent
investments than the Funds. Processing Organizations may also impose other
charges or restrictions different from those applicable to shareholders who
invest in the Funds directly. A Processing Organization, rather than its
customers, may be the shareholder of record of your shares. The Funds are not
responsible for the failure of any Processing Organization to carry out its
obligations to its customers. Certain Processing Organizations may receive
compensation from Janus Capital or its affiliates and certain Processing
Organizations may receive compensation from the Funds for shareholder
recordkeeping and similar services.
 
TAXPAYER IDENTIFICATION NUMBER
On the application or other appropriate form, you will be asked to certify that
your Social Security or taxpayer identification number is correct and that you
are not subject to backup withholding for failing to report income to the IRS.
If you are subject to the 31% backup withholding or you did not certify your
taxpayer identification, the IRS requires the Funds to withhold 31% of any
dividends paid and redemption or exchange proceeds. In addition to the 31%
backup withholding, you may be subject to a $50 fee to reimburse the Funds for
any penalty that the IRS may impose.
 
SHARE CERTIFICATES
Most shareholders choose not to hold their shares in certificate form because
account transactions such as exchanges and redemptions cannot be completed until
the certificate
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    37
    
<PAGE>   
 
has been returned to the Funds. The Funds will issue share certificates upon
written request only. Share certificates will not be issued until the shares
have been held for at least 15 days and will not be issued for accounts that do
not meet the minimum investment requirements. Share certificates cannot be
issued for retirement accounts. In addition, if the certificate is lost, there
may be a replacement charge.
 
INVOLUNTARY REDEMPTIONS
The Funds reserve the right to close an account if the shareholder is deemed to
engage in activities which are illegal or otherwise believed to be detrimental
to the Funds.
 
TELEPHONE TRANSACTIONS
You may initiate many transactions by telephone. The Funds and their agents will
not be responsible for any losses resulting from unauthorized transactions when
procedures designed to verify the identity of the caller are followed.
 
   
It may be difficult to reach an Investor Service Representative by telephone
during periods of unusual market activity. If you are unable to reach a
representative by telephone, please consider sending written instructions,
stopping by a Service Center or, in the case of purchases, exchanges,
redemptions and electronic transfers, calling the Janus Xpress Line.
    
 
TEMPORARY SUSPENSION OF SERVICES
The Funds or their agents may, in case of emergency, temporarily suspend
telephone transactions and other shareholder services.
 
ADDRESS CHANGES
To change the address on your account, call 1-800-525-3713 or send a written
request signed by all account owners. Include the name of your Fund(s), the
account number(s), the name(s) on the account and both the old and new
addresses. Certain options may be suspended for 10 days following an address
change unless a signature guarantee is provided.
 
REGISTRATION CHANGES
To change the name on an account, the shares are generally transferred to a new
account. In some cases, legal documentation may be required. For more
information, call 1-800-525-3713.
 
STATEMENTS AND REPORTS
   
Investors participating in an automatic investment program will receive
quarterly confirmations of all transactions. In addition, the Funds will send
you an immediate transaction confirmation statement after every non-systematic
transaction. The Growth Funds distribute dividend information annually. The
Combination Funds distribute dividend information quarterly.
    
 
Financial reports for the Funds, which include a list of the Funds' portfolio
holdings, will be mailed semiannually to all shareholders. To reduce expenses,
only one copy of most financial reports will be mailed to accounts with the same
record address. Upon request, such reports will be mailed to all accounts in the
same household. Please call 1-800-525-3713 if you would like to receive
additional reports.
 
   
 38   JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
                            MANAGEMENT OF THE FUNDS
 
TRUSTEES
The Trustees oversee the business affairs of the Trust and are responsible for
major decisions relating to each Fund's investment objectives and policies. The
Trustees delegate the day-to-day management of the Funds to the officers of the
Trust and meet at least quarterly to review the Funds' investment policies,
performance, expenses and other business affairs.
 
INVESTMENT ADVISER
Janus Capital, 100 Fillmore Street, Denver, Colorado 80206-4928, is the
investment adviser to each of the Funds and is responsible for the day-to-day
management of the investment portfolios and other business affairs of the Funds.
 
Janus Capital began serving as investment adviser to Janus Fund at its inception
in 1970 and currently serves as investment adviser to all of the Janus funds, as
well as adviser or subadviser to other mutual funds and individual, corporate,
charitable and retirement accounts.
 
Kansas City Southern Industries, Inc. ("KCSI") owns approximately 83% of the
outstanding voting stock of Janus Capital, most of which it acquired in 1984.
KCSI is a publicly traded holding company whose primary subsidiaries are engaged
in transportation, information processing and financial services. Thomas H.
Bailey, President and Chairman of the Board of Janus Capital, owns approximately
12% of its voting stock and, by agreement with KCSI, selects a majority of Janus
Capital's Board.
 
Janus Capital furnishes continuous advice and recommendations concerning each
Fund's investments. Janus Capital also furnishes certain administrative,
compliance and accounting services for the Funds, and may be reimbursed by the
Funds for its costs in providing those services. In addition, Janus Capital
employees serve as officers of the Trust and Janus Capital provides office space
for the Funds and pays the salaries, fees and expenses of all Fund officers and
those Trustees who are affiliated with Janus Capital.
 
INVESTMENT PERSONNEL
PORTFOLIO MANAGERS
   
DAVID J. CORKINS is Executive Vice President and portfolio manager of Janus
Growth and Income Fund which he has managed since August 1997. He previously
served as an assistant portfolio manager of Janus Mercury Fund. He joined Janus
in 1995 as a research analyst specializing in domestic financial services
companies and a variety of foreign industries. Prior to joining Janus he was the
Chief Financial Officer of Chase U.S. Consumer Services, Inc., a Chase Manhattan
mortgage business. He holds a Bachelor of Arts in English and Russian from
Dartmouth and received his Master of Business Administration from Columbia
University in 1993.
    
 
JAMES P. CRAIG, III is Chief Investment Officer of Janus Capital. He is
Executive Vice President and portfolio manager of Janus Fund, which he has
managed since 1986. He is
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    39
    
<PAGE>   
 
also Executive Vice President and a co-manager of Janus Venture Fund, which he
has managed since February 1, 1997. Mr. Craig previously managed Janus Venture
Fund from its inception to December 1993 and Janus Balanced Fund from December
1993 to December 1995. He holds a Bachelor of Arts in Business from the
University of Alabama and a Master of Arts in Finance from the Wharton School of
the University of Pennsylvania.
 
   
DAVID C. DECKER is Executive Vice President and portfolio manager of Janus
Special Situations Fund. He is an assistant portfolio manager of Janus Fund. He
joined Janus in 1992 as a research analyst and focused on companies in the
automotive and defense industries prior to assuming management responsibility
for the Fund. He obtained his Master of Business Administration in finance from
the Fuqua School of Business at Duke University and a bachelor's degree in
economics and political science from Tufts University. He is also a Chartered
Financial Analyst.
    
 
JAMES P. GOFF is Executive Vice President and portfolio manager of Janus
Enterprise Fund. Mr. Goff joined Janus Capital in 1988 and has managed this Fund
since its inception. Mr. Goff managed or co-managed Janus Venture Fund from
December 1993 to February 1, 1997. He holds a Bachelor of Arts in Economics from
Yale University and is a Chartered Financial Analyst.
 
HELEN YOUNG HAYES is Executive Vice President and portfolio manager of Janus
Worldwide Fund and Janus Overseas Fund. Ms. Hayes joined Janus Capital in 1987
and has managed or co-managed Janus Worldwide Fund and Janus Overseas Fund since
their inceptions. She holds a Bachelor of Arts in Economics from Yale University
and is a Chartered Financial Analyst.
 
WARREN B. LAMMERT is Executive Vice President and portfolio manager of Janus
Mercury Fund. Mr. Lammert joined Janus Capital in 1987 and has managed Janus
Mercury Fund since its inception and Janus Balanced Fund from its inception to
December 1993. He also co-managed Janus Venture Fund from December 1993 to
December 1996. He holds a Bachelor of Arts in Economics from Yale University and
a Master of Science in Economic History from the London School of Economics and
is a Chartered Financial Analyst.
 
   
BLAINE P. ROLLINS is Executive Vice President and portfolio manager of Janus
Balanced Fund, which he has managed since January 1996, and Janus Equity Income
Fund, which he has managed since inception. He is an assistant portfolio manager
of Janus Fund. He has been an assistant portfolio manager of Janus Fund since
January 1995. Mr. Rollins joined Janus Capital in 1990 and gained experience as
a fixed-income trader and equity research analyst prior to assuming management
responsibility for Janus Balanced Fund. He holds a Bachelor of Science in
Finance from the University of Colorado and is a Chartered Financial Analyst.
    
 
   
SCOTT W. SCHOELZEL is Executive Vice President and portfolio manager of Janus
Twenty Fund, which he has managed since August 1997. He previously managed Janus
Olympus Fund from its inception to August 1997. Mr. Schoelzel joined Janus
Capital in January 1994 as Vice President of Investments. From 1991-1993, Mr.
Schoelzel was a portfolio manager at Founders Asset Management, Denver,
Colorado. He holds a Bachelor of Arts in Business from Colorado College.
    
 
   
 40   JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
   
CLAIRE YOUNG is Executive Vice President and portfolio manager of Janus Olympus
Fund which she has managed since August 1997. She previously served as an
assistant portfolio manager of Janus Growth and Income Fund and Janus Twenty
Fund. Ms. Young joined Janus Capital in 1992 as a research analyst. She holds a
Bachelor of Science in Electrical Engineering from Yale University and is a
Chartered Financial Analyst.
    
 
   
ASSISTANT PORTFOLIO MANAGER
    
   
LAURENCE J. CHANG is assistant portfolio manager of Janus Overseas Fund and
Janus Worldwide Fund. He received an undergraduate degree with honors in
religion and philosophy from Dartmouth College and a Master's Degree in
Political Science from Stanford University. He is a Chartered Financial Analyst.
    
 
   
PERSONAL INVESTING
    
Janus Capital does not permit portfolio managers to purchase and sell securities
for their own accounts, except under the limited exceptions contained in Janus
Capital's policy governing personal investing. Janus Capital's policy requires
investment and other personnel to conduct their personal investment activities
in a manner that Janus Capital believes is not detrimental to the Funds or Janus
Capital's other advisory clients. See the SAI for more detailed information.
 
BREAKDOWN OF MANAGEMENT EXPENSES
   
Each Fund pays Janus Capital a management fee which is calculated daily and paid
monthly. The advisory agreement with each Fund spells out the management fee and
other expenses that the Funds must pay. Each of the Growth Funds and Combination
Funds is subject to the following management fee schedule (expressed as an
annual rate):
    
 
<TABLE>
<CAPTION>
                                         AVERAGE DAILY NET     ANNUAL RATE
                                           ASSETS OF FUND      PERCENTAGE (%)
    <S>                                  <C>                 <C>
</TABLE>
 
- --------------------------------------------------------------------------------
 
   
<TABLE>
    <S>                                  <C>                 <C>
                                         First $300 Million       0.75
                                         Next $200 Million        0.70
                                         Over $500 Million        0.65
</TABLE>
    
 
- --------------------------------------------------------------------------------
 
   
Differences in the actual management fees incurred by the Funds are due
primarily to variances in the asset size of the Funds. As asset size increases,
the annual rate of the management fee declines in accordance with the above
schedule. In addition, each Fund incurs expenses not assumed by Janus Capital,
including transfer agent and custodian fees and expenses, legal and auditing
fees, printing and mailing costs of sending reports and other information to
existing shareholders, and independent Trustees' fees and expenses. The Annual
Fund Operating Expenses table on page 7 lists the actual management fees and
total operating expenses of each Fund for the most recent fiscal year.
    
 
PORTFOLIO TRANSACTIONS
Purchases and sales of securities on behalf of each Fund are executed by
broker-dealers selected by Janus Capital. Broker-dealers are selected on the
basis of their ability to obtain best price and execution for a Fund's
transactions and recognizing brokerage, research and other services provided to
the Fund and to Janus Capital. Janus Capital may also consider payments made by
brokers effecting transactions for a Fund i) to the Fund
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    41
    
<PAGE>   
 
   
or ii) to other persons on behalf of the Fund for services provided to the Fund
for which it would be obligated to pay. Janus Capital may also consider sales of
shares of a Janus fund as a factor in the selection of broker-dealer to execute
transactions. The Funds' Trustees have authorized Janus Capital to place
portfolio transactions on an agency basis with a broker-dealer affiliated with
Janus Capital. When transactions for a Fund are effected with that
broker-dealer, the commissions payable by the Fund are credited against certain
Fund operating expenses serving to reduce those expenses. The SAI further
explains the selection of broker-dealers.
    
 
OTHER SERVICE PROVIDERS
The following parties provide the Funds with administrative and other services.
 
CUSTODIAN
State Street Bank and Trust Company
P.O. Box 0351
Boston, Massachusetts 02117-0351
 
TRANSFER AGENT
Janus Service Corporation
P.O. Box 173375
Denver, Colorado 80217-3375
 
DISTRIBUTOR
Janus Distributors, Inc.
100 Fillmore Street
Denver, Colorado 80206-4928
 
Janus Service Corporation and Janus Distributors, Inc. are wholly-owned
subsidiaries of Janus Capital.
 
OTHER INFORMATION
ORGANIZATION
The Trust is a "mutual fund" that was organized as a Massachusetts business
trust on February 11, 1986. A mutual fund is an investment vehicle that pools
money from numerous investors and invests the money to achieve a specified
objective.
 
   
As of the date of this Prospectus, the Trust offers 19 separate series, three of
which currently offer three classes of shares. This Prospectus describes eleven
series of the Trust; the other series are offered by separate prospectuses.
    
 
SHAREHOLDER MEETINGS
The Trust does not intend to hold annual shareholder meetings. However, special
meetings may be called for a specific Fund or for the Trust as a whole for
purposes such as electing or removing Trustees, terminating or reorganizing the
Trust, changing fundamental policies, or for any other purpose requiring a
shareholder vote under the 1940 Act. Separate votes are taken by each Fund only
if a matter affects or requires the vote of only that Fund or that Fund's
interest in the matter differs from the interest of
 
   
 42   JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
other portfolios of the Trust. As a shareholder, you are entitled to one vote
for each share that you own.
 
SIZE OF FUNDS
The Funds have no present plans to limit their size. However, any Fund may
discontinue sales of its shares if management believes that continued sales may
adversely affect the Fund's ability to achieve its investment objective. If
sales of a Fund are discontinued, it is expected that existing shareholders of
that Fund would be permitted to continue to purchase shares and to reinvest any
dividends or capital gains distributions, absent highly unusual circumstances.
 
MASTER/FEEDER OPTION
   
The Trust may in the future seek to achieve any Fund's investment objective by
investing all of that Fund's assets in another investment company having the
same investment objective and substantially the same investment policies and
restrictions as those applicable to that Fund. Unless otherwise required by law,
this policy may be implemented by the Trustees without shareholder approval.
    
 
   
YEAR 2000
    
   
Many computer systems use six-digit fields to store dates. With the approach of
the year 2000, these fields must be converted to eight-digit fields in order to
recognize the difference between 1900 and 2000. Failure to adequately address
this issue could have potentially serious repercussions. Preparing for Year 2000
is a high priority for Janus Capital, which has established a dedicated group to
address this issue and has entered into a consulting arrangement with one of the
foremost experts in Year 2000 compliance to assess systems implications for
Janus Capital. Janus Capital does not anticipate that the move to Year 2000 will
have a material impact on its ability to continue to provide the Funds with
service at current levels.
    
 
                            DISTRIBUTIONS AND TAXES
 
DISTRIBUTIONS
   
TO AVOID TAXATION, THE INTERNAL REVENUE CODE REQUIRES EACH FUND TO DISTRIBUTE
NET INCOME AND ANY NET CAPITAL GAINS REALIZED BY ITS INVESTMENTS ANNUALLY. A
FUND'S INCOME FROM DIVIDENDS AND INTEREST AND ANY NET REALIZED SHORT-TERM
CAPITAL GAINS ARE PAID TO SHAREHOLDERS AS ORDINARY INCOME DIVIDENDS. NET
REALIZED LONG-TERM GAINS ARE PAID TO SHAREHOLDERS AS CAPITAL GAINS
DISTRIBUTIONS.
    
 
DISTRIBUTION SCHEDULE
 
<TABLE>
<CAPTION>
                                   DIVIDENDS                      CAPITAL GAINS
<S>                    <C>                                <C>
Growth Funds           Declared and paid in December      Declared and paid in December
- ------------------------------------------------------------------------------------
Combination            Declared and paid in March, June,  Declared and paid in December
  Funds                September and December
</TABLE>
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    43
    
<PAGE>   
 
HOW DISTRIBUTIONS AFFECT A FUND'S NAV
Distributions are paid to shareholders as of the record date of a distribution
of a Fund, regardless of how long the shares have been held. Dividends and
capital gains awaiting distribution are included in each Fund's daily NAV. The
share price of a Fund drops by the amount of the distribution, net of any
subsequent market fluctuations. As an example, assume that on December 31, Janus
Fund declared a dividend in the amount of $0.25 per share. If Janus Fund's share
price was $10.00 on December 30, the Fund's share price on December 31 would be
$9.75, barring market fluctuations. Shareholders should be aware that
distributions from a taxable mutual fund are not value-enhancing and may create
income tax obligations.
 
"BUYING A DIVIDEND"
If you purchase shares of a Fund just before the distribution, you will pay the
full price for the shares and receive a portion of the purchase price back as a
taxable distribution. This is referred to as "buying a dividend." In the above
example, if you bought shares on December 30, you would have paid $10.00 per
share. On December 31, the Fund would pay you $0.25 per share as a dividend and
your shares would now be worth $9.75 per share. Unless your account is set up as
a tax-deferred account, dividends paid to you would be included in your gross
income for tax purposes even though you may not have participated in the
increase in NAV of the Fund, whether or not you reinvested the dividends.
 
DISTRIBUTION OPTIONS
   
When you open an account, you must specify on your application how you want to
receive your distributions. You may change your distribution option at any time
by writing the Funds at one of the addresses on page 31 or calling
1-800-525-3713. The Funds offer the following options:
    
 
1. REINVESTMENT OPTION. You may reinvest your income dividends and capital gains
   distributions in additional shares. This option is assigned automatically if
   no other choice is made.
 
2. CASH OPTION. You may receive your income dividends and capital gains
   distributions in cash.
 
3. REINVEST AND CASH OPTION. You may receive either your income dividends or
   capital gains distributions in cash and reinvest the other in additional
   shares.
 
4. REDIRECT OPTION. You may direct your dividends or capital gains to purchase
   shares of another Janus fund.
 
The Funds reserve the right to reinvest into your account undeliverable and
uncashed dividend and distribution checks that remain outstanding for six months
in shares of the applicable Fund at the NAV next computed after the check is
cancelled. Subsequent distributions may also be reinvested.
 
TAXES
   
As with any investment, you should consider the tax consequences of investing in
the Funds. The following discussion does not apply to tax-deferred accounts, nor
is it a
    
 
   
 44   JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
complete analysis of the federal tax implications of investing in the Funds. You
may wish to consult your own tax adviser. Additionally, state or local taxes may
apply to your investment, depending upon the laws of your state of residence.
 
TAXES ON DISTRIBUTIONS
   
Dividends and distributions of the Funds are subject to federal income tax,
regardless of whether the distribution is made in cash or reinvested in
additional shares of a Fund. In certain states, a portion of the dividends and
distributions (depending on the sources of a Fund's income) may be exempt from
state and local taxes. Information regarding the tax status of income dividends
and capital gains distributions will be mailed to shareholders on or before
January 31st of each year. Account tax information will also be sent to the IRS.
    
 
TAXATION OF THE FUNDS
   
The Funds may from year to year make the election permitted under section 853 of
the Internal Revenue Code to pass through such taxes to shareholders as a
foreign tax credit. If such an election is not made, any foreign taxes paid or
accrued will represent an expense to the Funds which will reduce their
investment income.
    
 
The Funds do not expect to pay any federal income or excise taxes because they
intend to meet certain requirements of the Internal Revenue Code. It is
important that the Funds meet these requirements so that any earnings on your
investment will not be taxed twice.
 
                               PERFORMANCE TERMS
 
This section will help you understand various terms that are commonly used to
describe a Fund's performance. You may see references to these terms in our
newsletters, advertisements and in media articles. Our newsletters and
advertisements may include comparisons of the Fund's performance to the
performance of other mutual funds, mutual fund averages or recognized stock
market indices. The Growth and Combination Funds generally measure performance
in terms of total return.
 
   
CUMULATIVE TOTAL RETURN represents the actual rate of return on an investment
for a specified period. The Financial Highlights tables beginning on page 8 show
total return for a single fiscal period. Cumulative total return is generally
quoted for more than one year (e.g., the life of the Fund). A cumulative total
return does not show interim fluctuations in the value of an investment.
    
 
AVERAGE ANNUAL TOTAL RETURN represents the average annual percentage change of
an investment over a specified period. It is calculated by taking the cumulative
total return for the stated period and determining what constant annual return
would have produced the same cumulative return. Average annual returns for more
than one year tend to smooth out variations in a Fund's return and are not the
same as actual annual results.
 
THE FUNDS IMPOSE NO SALES OR OTHER CHARGES THAT WOULD AFFECT TOTAL RETURN
COMPUTATIONS. FUND PERFORMANCE FIGURES ARE BASED UPON HISTORICAL RESULTS AND ARE
NOT INTENDED TO INDICATE FUTURE PERFORMANCE. INVESTMENT RETURNS AND NET ASSET
VALUE WILL FLUCTUATE SO THAT AN INVESTOR'S SHARES, WHEN REDEEMED, MAY BE WORTH
MORE OR LESS THAN THEIR ORIGINAL COST.
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    45
    
<PAGE>   
 
                                   APPENDIX A
 
GLOSSARY OF INVESTMENT TERMS
This glossary provides a more detailed description of some of the types of
securities and other instruments in which the Funds may invest. The Funds may
invest in these instruments to the extent permitted by their investment
objectives and policies. The Funds are not limited by this discussion and may
invest in any other types of instruments not precluded by the policies discussed
elsewhere in this Prospectus. Please refer to the SAI for a more detailed
discussion of certain instruments.
 
I. EQUITY AND DEBT SECURITIES
   
BONDS are debt securities issued by a company, municipality, government or
government agency. The issuer of a bond is required to pay the holder the amount
of the loan (or par value of the bond) at a specified maturity and to make
scheduled interest payments.
    
 
COMMERCIAL PAPER is a short-term debt obligation with a maturity ranging from 1
to 270 days issued by banks, corporations and other borrowers to investors
seeking to invest idle cash. For example, the Funds may purchase commercial
paper issued under Section 4(2) of the Securities Act of 1933.
 
COMMON STOCK represents a share of ownership in a company and usually carries
voting rights and earns dividends. Unlike preferred stock, dividends on common
stock are not fixed but are declared at the discretion of the issuer's board of
directors.
 
CONVERTIBLE SECURITIES are preferred stocks or bonds that pay a fixed dividend
or interest payment and are convertible into common stock at a specified price
or conversion ratio.
 
DEPOSITARY RECEIPTS are receipts for shares of a foreign-based corporation that
entitle the holder to dividends and capital gains on the underlying security.
Receipts include those issued by domestic banks (American Depositary Receipts),
foreign banks (Global or European Depositary Receipts) and broker-dealers
(depositary shares).
 
   
FIXED-INCOME SECURITIES are securities that pay a specified rate of return. The
term generally includes short- and long-term government, corporate and municipal
obligations that pay a specified rate of interest or coupons for a specified
period of time, and preferred stock, which pays fixed dividends. Coupon and
dividend rates may be fixed for the life of the issue or, in the case of
adjustable and floating rate securities, for a shorter period.
    
 
HIGH-YIELD/HIGH-RISK SECURITIES are securities that are rated below investment
grade by the primary rating agencies (e.g., BB or lower by Standard & Poor's and
Ba or lower by Moody's). Other terms commonly used to describe such securities
include "lower rated bonds," "noninvestment grade bonds" and "junk bonds."
 
MORTGAGE- AND ASSET-BACKED SECURITIES are shares in a pool of mortgages or other
debt. These securities are generally pass-through securities, which means that
principal and interest payments on the underlying securities (less servicing
fees) are passed through to shareholders on a pro rata basis. These securities
involve prepayment risk,
 
   
 46   JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
which is the risk that the underlying mortgages or other debt may be refinanced
or paid off prior to their maturities during periods of declining interest
rates. In that case, a portfolio manager may have to reinvest the proceeds from
the securities at a lower rate. Potential market gains on a security subject to
prepayment risk may be more limited than potential market gains on a comparable
security that is not subject to prepayment risk.
 
   
PASSIVE FOREIGN INVESTMENT COMPANIES (PFICS) are any foreign corporations which
generate certain amounts of passive income or hold certain amounts of assets for
the production of passive income. Passive income includes dividends, interest,
royalties, rents and annuities. To avoid taxes and interest that the Funds must
pay if these investments are profitable, the Funds may make various elections
permitted by the tax laws. These elections could require that the Funds
recognize taxable income, which in turn must be distributed, before the
securities are sold and before cash is received to pay the distributions.
    
 
PAY-IN-KIND BONDS are debt securities that normally give the issuer an option to
pay cash at a coupon payment date or give the holder of the security a similar
bond with the same coupon rate and a face value equal to the amount of the
coupon payment that would have been made.
 
PREFERRED STOCK is a class of stock that generally pays dividends at a specified
rate and has preference over common stock in the payment of dividends and
liquidation. Preferred stock generally does not carry voting rights.
 
REPURCHASE AGREEMENTS involve the purchase of a security by a Fund and a
simultaneous agreement by the seller (generally a bank or dealer) to repurchase
the security from the Fund at a specified date or upon demand. This technique
offers a method of earning income on idle cash. These securities involve the
risk that the seller will fail to repurchase the security, as agreed. In that
case, a Fund will bear the risk of market value fluctuations until the security
can be sold and may encounter delays and incur costs in liquidating the
security.
 
REVERSE REPURCHASE AGREEMENTS involve the sale of a security by a Fund to
another party (generally a bank or dealer) in return for cash and an agreement
by the Fund to buy the security back at a specified price and time. This
technique will be used primarily to provide cash to satisfy unusually high
redemption requests, or for other temporary or emergency purposes.
 
RULE 144A SECURITIES are securities that are not registered for sale to the
general public under the Securities Act of 1933, but that may be resold to
certain institutional investors.
 
STANDBY COMMITMENTS are obligations purchased by a Fund from a dealer that give
the Fund the option to sell a security to the dealer at a specified price.
 
STEP COUPON BONDS are debt securities that trade at a discount from their face
value and pay coupon interest. The discount from the face value depends on the
time remaining until cash payments begin, prevailing interest rates, liquidity
of the security and the perceived credit quality of the issuer.
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    47
    
<PAGE>   
 
STRIP BONDS are debt securities that are stripped of their interest (usually by
a financial intermediary) after the securities are issued. The market value of
these securities generally fluctuates more in response to changes in interest
rates than interest-paying securities of comparable maturity.
 
U.S. GOVERNMENT SECURITIES include direct obligations of the U.S. government
that are supported by its full faith and credit. Treasury bills have initial
maturities of less than one year, Treasury notes have initial maturities of one
to ten years and Treasury bonds may be issued with any maturity but generally
have maturities of at least ten years. U.S. government securities also include
indirect obligations of the U.S. government that are issued by federal agencies
and government sponsored entities. Unlike Treasury securities, agency securities
generally are not backed by the full faith and credit of the U.S. government.
Some agency securities are supported by the right of the issuer to borrow from
the Treasury, others are supported by the discretionary authority of the U.S.
government to purchase the agency's obligations and others are supported only by
the credit of the sponsoring agency.
 
VARIABLE AND FLOATING RATE SECURITIES have variable or floating rates of
interest and, under certain limited circumstances, may have varying principal
amounts. These securities pay interest at rates that are adjusted periodically
according to a specified formula, usually with reference to some interest rate
index or market interest rate. The floating rate tends to decrease the
security's price sensitivity to changes in interest rates.
 
WARRANTS are securities, typically issued with preferred stock or bonds, that
give the holder the right to buy a proportionate amount of common stock at a
specified price, usually at a price that is higher than the market price at the
time of issuance of the warrant. The right may last for a period of years or
indefinitely.
 
WHEN-ISSUED, DELAYED DELIVERY AND FORWARD TRANSACTIONS generally involve the
purchase of a security with payment and delivery at some time in the
future -- i.e., beyond normal settlement. The Funds do not earn interest on such
securities until settlement and bear the risk of market value fluctuations in
between the purchase and settlement dates. New issues of stocks and bonds,
private placements and U.S. government securities may be sold in this manner.
 
ZERO COUPON BONDS are debt securities that do not pay regular interest at
regular intervals, but are issued at a discount from face value. The discount
approximates the total amount of interest the security will accrue from the date
of issuance to maturity. The market value of these securities generally
fluctuates more in response to changes in interest rates than interest-paying
securities of comparable maturity.
 
II. FUTURES, OPTIONS AND OTHER DERIVATIVES
   
FORWARD CONTRACTS are contracts to purchase or sell a specified amount of a
financial instrument for an agreed upon price at a specified time. Forward
contracts are not currently exchange traded and are typically negotiated on an
individual basis. The Funds may enter into forward currency contracts to hedge
against declines in the value of securities denominated in, or whose value is
tied to, a currency other than the U.S. dollar or to reduce the impact of
currency appreciation on purchases of such securities. They may also enter into
forward contracts to purchase or sell securities or other financial indices.
    
   
 48   JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
FUTURES CONTRACTS are contracts that obligate the buyer to receive and the
seller to deliver an instrument or money at a specified price on a specified
date. The Funds may buy and sell futures contracts on foreign currencies,
securities and financial indices including interest rates or an index of U.S.
government, foreign government, equity or fixed-income securities. The Funds may
also buy options on futures contracts. An option on a futures contract gives the
buyer the right, but not the obligation, to buy or sell a futures contract at a
specified price on or before a specified date. Futures contracts and options on
futures are standardized and traded on designated exchanges.
 
INDEXED/STRUCTURED SECURITIES are typically short- to intermediate-term debt
securities whose value at maturity or interest rate is linked to currencies,
interest rates, equity securities, indices, commodity prices or other financial
indicators. Such securities may be positively or negatively indexed (i.e. their
value may increase or decrease if the reference index or instrument
appreciates). Indexed/structured securities may have return characteristics
similar to direct investments in the underlying instruments and may be more
volatile than the underlying instruments. A Fund bears the market risk of an
investment in the underlying instruments, as well as the credit risk of the
issuer.
 
INTEREST RATE SWAPS involve the exchange by two parties of their respective
commitments to pay or receive interest (e.g., an exchange of floating rate
payments for fixed rate payments).
 
OPTIONS are the right, but not the obligation, to buy or sell a specified amount
of securities or other assets on or before a fixed date at a predetermined
price. The Funds may purchase and write put and call options on securities,
securities indices and foreign currencies.
 
   
JANUS EQUITY FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    49
    



<PAGE>   
 
                             JANUS INVESTMENT FUND
 
                               JANUS INCOME FUNDS
 
                              100 Fillmore Street
                             Denver, CO 80206-4928
                                 (800) 525-3713
   
                              http://www.Janus.com
    
 
   
                               FEBRUARY 17, 1998
    
 
   
This prospectus describes four mutual funds that invest primarily in
income-producing securities (the "Fixed-Income Funds") and three money market
funds that seek current income consistent with stability of capital (the "Money
Market Funds"). Only the Investor Shares of the Money Market Funds, a separate
class of shares of Janus Money Market Fund, Janus Government Money Market Fund
and Janus Tax-Exempt Money Market Fund (collectively, the "Shares"), are offered
by this Prospectus. Janus Capital Corporation ("Janus Capital") serves as
investment adviser to each Fund. Janus Capital has been in the investment
advisory business for over 27 years and currently manages approximately $70
billion in assets.
    
 
   
JANUS FLEXIBLE INCOME FUND AND JANUS HIGH-YIELD FUND MAY INVEST ALL OF THEIR
ASSETS IN HIGH-YIELD CORPORATE DEBT SECURITIES, COMMONLY KNOWN AS "JUNK BONDS."
SEE "ADDITIONAL RISK FACTORS" ON PAGE 20 FOR THE RISKS ASSOCIATED WITH INVESTING
IN THESE SECURITIES.
    
 
AN INVESTMENT IN A MONEY MARKET FUND IS NEITHER INSURED NOR GUARANTEED BY THE
U.S. GOVERNMENT. THERE IS NO ASSURANCE THAT A MONEY MARKET FUND WILL BE ABLE TO
MAINTAIN A STABLE NET ASSET VALUE OF $1.00 PER SHARE.
 
Each Fund is a series of Janus Investment Fund (the "Trust"). The Trust is
registered with the Securities and Exchange Commission ("SEC") as an open-end
management investment company. This Prospectus contains information about the
Funds that you should consider before investing. Please read it carefully and
keep it for future reference.
 
   
Additional information about the Funds is contained in a Statement of Additional
Information ("SAI") filed with the SEC. The SAI dated February 17, 1998, is
incorporated by reference into this Prospectus. For a copy of the SAI, write or
call the Funds at the address or phone number listed above. The SEC maintains a
Web site located at http://www.sec.gov that contains the SAI, material
incorporated by reference, and other information regarding the Funds.
    
 
   
THE FUNDS' SHARES ARE NOT BANK DEPOSITS, ARE NOT ENDORSED OR GUARANTEED BY ANY
BANK, AND ARE NOT INSURED BY THE FEDERAL DEPOSIT INSURANCE CORPORATION, THE
FEDERAL RESERVE BOARD, OR ANY OTHER GOVERNMENT AGENCY.
    
 
   
THESE SECURITIES HAVE NOT BEEN APPROVED BY THE SEC NOR HAS THE SEC PASSED ON THE
ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A
CRIMINAL OFFENSE.
    
 
THIS PROSPECTUS DOES NOT CONSTITUTE AN OFFER TO SELL SECURITIES IN ANY STATE OR
OTHER JURISDICTION TO ANY PERSON TO WHOM IT IS UNLAWFUL TO MAKE SUCH AN OFFER IN
SUCH STATE OR OTHER JURISDICTION.
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                    FEBRUARY 17, 1998    1
    
<PAGE>   
 
                                    CONTENTS
 
   
<TABLE>
<S>                                            <C>
FUNDS AT A GLANCE
Brief description of the Funds...............    3
EXPENSE INFORMATION
Each Fund's annual operating expenses........    6
Financial Highlights - a summary of financial
  data.......................................    7
THE FIXED-INCOME FUNDS IN DETAIL
Investment Objective and Policies............   13
General Portfolio Policies...................   18
Additional Risk Factors......................   20
THE MONEY MARKET FUNDS IN DETAIL
Investment Objectives, Policies and
   Techniques................................   23
SHAREHOLDER'S MANUAL
Types of Account Ownership...................   31
How to Open Your Janus Account...............   33
How to Purchase Shares.......................   33
How to Exchange Shares.......................   35
How to Redeem Shares.........................   36
Shareholder Services and Account Policies....   38
MANAGEMENT OF THE FUNDS
Investment Adviser, Administrator and
   Investment Personnel......................   42
Personal Investing...........................   44
Management Expenses..........................   44
Portfolio Transactions.......................   45
Other Service Providers......................   45
Other Information............................   45
DISTRIBUTIONS AND TAXES
Distributions................................   47
Taxes........................................   49
PERFORMANCE TERMS
An Explanation of Performance Terms..........   49
APPENDIX A
Glossary of Investment Terms.................   51
APPENDIX B
Explanation of Rating Categories.............   56
</TABLE>
    
 
   
 2   JANUS INCOME FUNDS COMBINED PROSPECTUS                    FEBRUARY 17, 1998
    
<PAGE>   
 
                               FUNDS AT A GLANCE
 
   
This section is designed to provide you with a brief overview of the Funds and
their investment emphasis. A more detailed discussion of the Funds' investment
objectives and policies begins on page 13 and complete information on how to
purchase, redeem and exchange shares begins on page 33.
    
 
   
All Janus funds are no-load investments. This means you may purchase and sell
shares in any of our mutual funds without incurring any sales charges. If you
enroll in our low minimum initial investment program, you can open your account
for as little as $500 and a $100 subsequent purchase per month. Otherwise, the
minimum initial investment is $2,500 ($500 minimum for Individual Retirement
Accounts). For complete information on how to purchase, exchange and sell
shares, please see the Shareholder's Manual beginning on page 31.
    
 
FIXED-INCOME FUNDS
   
THE JANUS FIXED-INCOME FUNDS ARE DESIGNED FOR THOSE INVESTORS WHO PRIMARILY SEEK
CURRENT INCOME.
    
 
JANUS FLEXIBLE INCOME FUND
Fund Focus: A diversified fund that seeks to maximize total return from a
combination of income and capital appreciation by investing in income-producing
securities.
 
Fund Inception: July 1987
 
Fund Managers: Ronald V. Speaker
               Sandy R. Rufenacht
 
JANUS HIGH-YIELD FUND
Fund Focus: A diversified fund that seeks high current income as its primary
objective. Capital appreciation is a secondary objective when consistent with
the primary objective. The Fund seeks to achieve these objectives by investing
primarily in high-yield/high-risk fixed-income securities.
 
Fund Inception: December 1995
 
Fund Managers: Ronald V. Speaker
               Sandy R. Rufenacht
 
JANUS FEDERAL TAX-EXEMPT FUND
Fund Focus: A diversified fund that seeks a high level of current income exempt
from federal income tax by normally investing at least 80% of its assets in
municipal obligations whose interest is exempt from federal income taxes,
including the federal alternative minimum tax.
 
Fund Inception: May 1993
 
Fund Manager: Darrell W. Watters
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                    FEBRUARY 17, 1998    3
    
<PAGE>   
 
   
JANUS SHORT-TERM BOND FUND
    
Fund Focus: A diversified fund that seeks a high level of current income while
minimizing interest rate risk by investing in shorter term fixed-income
securities. Its average-weighted effective maturity is normally less than three
years.
 
Fund Inception: September 1992
 
Fund Manager: Sandy R. Rufenacht
 
MONEY MARKET FUNDS
 
JANUS MONEY MARKET FUND
Fund Focus: A money market mutual fund that seeks maximum current income to the
extent consistent with stability of capital. The Fund seeks to achieve this
objective by investing primarily in high quality debt obligations and
obligations of financial institutions.
 
Fund Inception: February 1995
 
Fund Manager: Sharon S. Pichler
 
JANUS GOVERNMENT MONEY MARKET FUND
Fund Focus: A money market mutual fund that seeks maximum current income to the
extent consistent with stability of capital. The Fund seeks to achieve this
objective by investing exclusively in obligations issued and/or guaranteed as to
principal and interest by the United States government or its agencies and
instrumentalities and repurchase agreements secured by such obligations.
 
Fund Inception: February 1995
 
Fund Manager: Sharon S. Pichler
 
JANUS TAX-EXEMPT MONEY MARKET FUND
Fund Focus: A money market mutual fund that seeks maximum current income that is
exempt from federal income taxes to the extent consistent with stability of
capital. The Fund seeks to achieve this objective by investing primarily in
municipal securities whose interest is exempt from federal income taxes,
including the federal alternative minimum tax.
 
Fund Inception: February 1995
 
   
Fund Manager: Sharon S. Pichler
    
 
   
 4   JANUS INCOME FUNDS COMBINED PROSPECTUS                    FEBRUARY 17, 1998
    
<PAGE>   
 
                              EXPENSE INFORMATION
 
   
The tables and example below are designed to assist you in understanding the
various costs and expenses that you will bear directly or indirectly as an
investor in the Funds. Shareholder Transaction Expenses are fees charged
directly to your individual account when you buy, sell or exchange shares. The
table below shows that you pay no such fees. Annual Operating Expenses are paid
out of each Fund's assets and include fees for portfolio management, maintenance
of shareholder accounts, shareholder servicing, accounting and other services.
Expenses may vary among the Funds for a number of reasons, including Fund size,
differences in management fees, average shareholder account size, and the extent
of foreign investments which entail greater transaction costs.
    
 
    SHAREHOLDER TRANSACTION EXPENSES
    (applicable to each Fund)
 
<TABLE>
         <S>                                              <C>
         Maximum sales load imposed on purchases          None
         Maximum sales load imposed on reinvested
           dividends                                      None
         Deferred sales charges on redemptions            None
         Redemption fee*                                  None
         Exchange fee                                     None
</TABLE>
 
    * There is an $8 service fee for redemptions by wire.
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                    FEBRUARY 17, 1998    5
    
<PAGE>   
 
ANNUAL OPERATING EXPENSES(1)
(expressed as a percentage of average net assets)
 
   
<TABLE>
<CAPTION>
- -----------------------------------------------------------------------------
                                      MANAGEMENT    OTHER     TOTAL OPERATING
                                         FEE       EXPENSES      EXPENSES
- -----------------------------------------------------------------------------
<S>                                   <C>          <C>        <C>
Janus Flexible Income Fund              0.60%       0.27%          0.87%
Janus High-Yield Fund(2)                0.74%       0.29%          1.03%
Janus Federal Tax-Exempt Fund(2)        0.16%       0.50%          0.66%
Janus Short-Term Bond Fund(2)           0.12%       0.55%          0.67%
Janus Money Market Fund - Investor
  Shares(2)                             0.10%       0.50%          0.60%
Janus Government Money Market
  Fund - Investor Shares(2)             0.10%       0.50%          0.60%
Janus Tax-Exempt Money Market
  Fund - Investor Shares(2)             0.10%       0.50%          0.60%
</TABLE>
    
 
- --------------------------------------------------------------------------------
 
   
(1) Annual Operating Expenses are based on expenses before expense offset
    arrangements for the fiscal year ended October 31, 1997. When applicable,
    all expenses are stated net of waivers by Janus Capital. Waivers for the
    Fixed-Income Funds are first applied against the management fee and then
    against other expenses.
    
 
   
(2) Net of waivers. Without such waivers, the Management Fee, Other Expenses and
    Total Operating Expenses would have been 0.75%, 0.29% and 1.04%,
    respectively, for Janus High-Yield Fund; 0.60%, 0.51% and 1.11%,
    respectively, for Janus Federal Tax-Exempt Fund; 0.65%, 0.55% and 1.20%,
    respectively, for Janus Short-Term Bond Fund; and 0.20%, 0.50% and 0.70% for
    each of the Money Market Funds - Investor Shares. Janus Capital may modify
    or terminate the waivers at any time upon at least 90 days' notice to the
    Trustees.
    
 
EXAMPLE
Assume you invest $1,000, the Funds return 5% annually and each Fund's expense
ratio remains as listed above. The example below shows the operating expenses
that you would indirectly bear as an investor in the Funds.
 
   
<TABLE>
<CAPTION>
- ----------------------------------------------------------------------------------
                                             1 YEAR   3 YEARS   5 YEARS   10 YEARS
- ----------------------------------------------------------------------------------
<S>                                          <C>      <C>       <C>       <C>
Janus Flexible Income Fund                    $ 9       $28       $48       $107
Janus High-Yield Fund                         $10       $33       $57       $126
Janus Federal Tax-Exempt Fund                 $ 7       $21       $37       $ 82
Janus Short-Term Bond Fund                    $ 7       $21       $37       $ 83
Janus Money Market Fund - Investor Shares     $ 6       $19       $33       $ 75
Janus Government Money Market
  Fund - Investor Shares                      $ 6       $19       $33       $ 75
Janus Tax-Exempt Money Market
  Fund - Investor Shares                      $ 6       $19       $33       $ 75
</TABLE>
    
 
- --------------------------------------------------------------------------------
 
THE EXAMPLE SHOULD NOT BE CONSIDERED A REPRESENTATION OF PAST OR FUTURE RETURNS
OR EXPENSES WHICH MAY BE MORE OR LESS THAN THOSE SHOWN.
 
   
 6   JANUS INCOME FUNDS COMBINED PROSPECTUS                    FEBRUARY 17, 1998
    
<PAGE>   
 
                              FINANCIAL HIGHLIGHTS
 
   
Unless otherwise noted, the information below is for fiscal periods ending on
October 31 of each year. The accounting firm of Price Waterhouse LLP has audited
the Funds' financial statements beginning with the year ended October 31, 1990.
Their report is included in the Funds' Annual Reports, which are incorporated by
reference into the SAI. A detailed explanation of the Financial Highlights can
be found on page 12.
    
 
   
<TABLE>
<CAPTION>
                                                          JANUS FLEXIBLE INCOME FUND
                                               1997+     1996    1995    1994    1993    1992(1)
<S>                                            <C>      <C>      <C>     <C>     <C>     <C>
- ----------------------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD                 $9.55   $8.96   $10.03  $9.26     $9.09
- ----------------------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income                                 0.73    0.72   0.74     0.77      0.68
 3. Net gains or (losses) on securities (both
    realized and unrealized)                              0.10    0.59   (0.86)   0.79      0.15
- ----------------------------------------------------------------------------------------------------
 4. Total from investment operations                      0.83    1.31   (0.12)   1.56      0.83
- ----------------------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)              (0.73)   (0.72)  (0.72)  (0.77)   (0.66)
 6. Distributions (from capital gains)                      --      --   (0.23)  (0.02)       --
- ----------------------------------------------------------------------------------------------------
 7. Total distributions                                 (0.73)   (0.72)  (0.95)  (0.79)   (0.66)
- ----------------------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                       $9.65   $9.55   $8.96   $10.03    $9.26
- ----------------------------------------------------------------------------------------------------
 9. Total return*                                        9.01%   15.35%  (1.26%) 17.48%    9.43%
- ----------------------------------------------------------------------------------------------------
10. Net assets, end of period (in millions)               $604    $580   $377     $473      $205
11. Average net assets for the period (in
    millions)                                             $604    $450   $429     $338      $144
12. Ratio of gross expenses to average net
    assets**                                             0.88%   0.96%    N/A      N/A       N/A
13. Ratio of net expenses to average net
    assets**                                             0.87%   0.96%   0.93%   1.00%(2)   1.00%(2)
14. Ratio of net investment income to average
    net assets**                                         7.60%   7.91%   7.75%   7.96%     8.98%
15. Portfolio turnover rate**                             214%    250%   137%     201%      210%
- ----------------------------------------------------------------------------------------------------
</TABLE>
    
 
(1) Fiscal period from January 1, 1992 to October 31, 1992.
   
(2) The ratio of net expenses to average net assets was 1.01% in 1993 and 1.21%
    in 1992.
    
   
 * Total return is not annualized for periods of less than one full year.
    
** Annualized for periods of less than one full year.
   
 + [To be filed by Amendment]
    
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                    FEBRUARY 17, 1998    7
    
<PAGE>   
 
   
(continued)
    
 
   
<TABLE>
<CAPTION>
                                                             JANUS FLEXIBLE INCOME FUND
                                                        1991(1)   1990(1)   1989(1)   1988(1)
<S>                                                     <C>       <C>       <C>       <C>
- --------------------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD                 $8.01     $9.35     $9.99      $9.92
- --------------------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income                                 0.68      0.95      0.97       0.92
 3. Net gains or (losses) on securities (both realized
    and unrealized)                                       1.29    (1.38)    (0.56)       0.09
- --------------------------------------------------------------------------------------------------
 4. Total from investment operations                      1.97    (0.43)      0.41       1.01
- --------------------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)              (0.72)    (0.91)    (0.97)     (0.92)
 6. Distributions (from capital gains)                  (0.17)        --    (0.08)     (0.02)
- --------------------------------------------------------------------------------------------------
 7. Total distributions                                 (0.89)    (0.91)    (1.05)     (0.94)
- --------------------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                       $9.09     $8.01     $9.35      $9.99
- --------------------------------------------------------------------------------------------------
 9. Total return*                                       25.98%    (4.62%)    4.12%     10.70%
- --------------------------------------------------------------------------------------------------
10. Net assets, end of period (in millions)                $72       $14       $18        $10
11. Average net assets for the period (in millions)        $33       $15       $15         $7
12. Ratio of gross expenses to average net assets**        N/A       N/A       N/A        N/A
13. Ratio of net expenses to average net assets**        1.00%(2)  1.00%(2)  1.00%(2)   1.00%(2)
14. Ratio of net investment income to average net
    assets**                                             9.38%    11.24%    10.00%      9.32%
15. Portfolio turnover rate**                              88%       96%       75%        76%
- -------------------------------------------------------------------------------------------------
</TABLE>
    
 
   
(1) Fiscal year ended on December 31st of each year.
    
   
(2) The ratio of net expenses to average net assets was 1.74% in 1991 before
    waivers of certain fund expenses. The ratio was 2% in prior years.
    
 * Total return is not annualized for periods of less than one full year.
** Annualized for periods of less than one full year.
 
   
<TABLE>
<CAPTION>
                                                                 JANUS HIGH-YIELD FUND
                                                       1997+            1996(1)
<S>                                                    <C>       <C>
- ------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD                                $10.00
- ------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income                                                 0.80
 3. Net gains or (losses) on securities (both
    realized and unrealized)                                              1.12
- ------------------------------------------------------------------------------------
 4. Total from investment operations                                      1.92
- ------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)                              (0.80)
 6. Distributions (from capital gains)                                      --
- ------------------------------------------------------------------------------------
 7. Total distributions                                                 (0.80)
- ------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                                      $11.12
- ------------------------------------------------------------------------------------
 9. Total return*                                                       19.71%
- ------------------------------------------------------------------------------------
10. Net assets, end of period (in millions)                               $211
11. Average net assets for the period (in millions)                        $88
12. Ratio of gross expenses to average net assets**                      1.01%(2)
13. Ratio of net expenses to average net assets**                        1.00%
14. Ratio of net investment income to average net
    assets**                                                             9.00%
15. Portfolio turnover rate**                                             324%
- ------------------------------------------------------------------------------------
</TABLE>
    
 
(1) Fiscal period from December 29, 1995 (inception) to October 31, 1996.
(2) The ratio was 1.18% before waiver of certain Fund expenses.
 * Total return is not annualized for periods of less than one full year.
** Annualized for periods of less than one full year.
   
 + [To be filed by Amendment]
    
 
   
 8   JANUS INCOME FUNDS COMBINED PROSPECTUS                    FEBRUARY 17, 1998
    
<PAGE>   

   
<TABLE>
<CAPTION>
                                                                       JANUS
                                                              FEDERAL TAX-EXEMPT FUND
                                                     1997+    1996      1995      1994      1993(1)
<S>                                                  <C>      <C>       <C>       <C>       <C>
- ----------------------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD                      $6.88     $6.45     $7.30     $7.00
- ----------------------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income                                      0.36      0.36      0.36      0.14
 3. Net gains or (losses) on securities (both
    realized and unrealized)                                   0.04      0.43     (0.83)     0.30
- ----------------------------------------------------------------------------------------------------
 4. Total from investment operations                           0.40      0.79     (0.47)     0.44
- ----------------------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)                    (0.36)    (0.36)    (0.36)    (0.14)
 6. Distributions (from capital gains)                           --        --     (0.02)       --
- ----------------------------------------------------------------------------------------------------
 7. Total distributions                                       (0.36)    (0.36)    (0.38)    (0.14)
- ----------------------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                            $6.92     $6.88     $6.45     $7.30
- ----------------------------------------------------------------------------------------------------
 9. Total return*                                              5.94%    12.60%    (6.62%)    6.33%
- ----------------------------------------------------------------------------------------------------
10. Net assets, end of period (in millions)                     $45       $33       $26       $27
11. Average net assets for the period (in millions)             $36       $29       $28       $16
12. Ratio of gross expenses to average net assets**            0.68%     0.70%      N/A       N/A
13. Ratio of net expenses to average net assets**              0.65%(2)  0.65%(2)  0.65%(2)  0.75%(2,3)
14. Ratio of net investment income to average net
    assets**                                                   5.18%     5.43%     5.20%     4.58%
15. Portfolio turnover rate**                                   225%      164%      160%      124%
- ----------------------------------------------------------------------------------------------------
</TABLE>
    
 
(1) Fiscal period from May 3, 1993 (inception) to October 31, 1993.
   
(2) The ratio of net expenses to average net assets was   % in 1997, 1.14% in
    1996, 1.31% in 1995, 1.41% in 1994 and 1.60% in 1993 before waiver of
    certain Fund expenses.
    
   
(3) The ratio of net expenses to average net assets reflects the Fund's previous
    expense limit of 1.00%. This limit was reduced to .65% as of August 1, 1993.
    
   
 * Total return is not annualized for periods of less than one full year.
    
** Annualized for periods of less than one full year.
   
 + [To be filed by Amendment]
    
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                    FEBRUARY 17, 1998    9
    
<PAGE>   

   
<TABLE>
<CAPTION>
                                                                         JANUS
                                                                  SHORT-TERM BOND FUND
                                                1997+   1996      1995      1994      1993        1992(1)
<S>                                             <C>     <C>       <C>       <C>       <C>         <C>
- --------------------------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD                $2.84     $2.87     $3.02     $2.98       $3.00
- --------------------------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income                                0.16      0.18      0.18      0.14        0.01
 3. Net gains or (losses) on securities (both 
    realized and unrealized)                             0.02     (0.03)    (0.15)     0.04       (0.02)
- --------------------------------------------------------------------------------------------------------
 4. Total from investment operations                     0.18      0.15      0.03      0.18       (0.01)
- --------------------------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)              (0.16)    (0.18)    (0.17)    (0.14)      (0.01)
 6. Distributions (from capital gains)                     --        --     (0.01)       --          --
- --------------------------------------------------------------------------------------------------------
 7. Total distributions                                 (0.16)    (0.18)    (0.18)    (0.14)      (0.01)
- --------------------------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                      $2.86     $2.84     $2.87     $3.02       $2.98
- --------------------------------------------------------------------------------------------------------
 9. Total return*                                        6.49%     5.55%     1.26%     6.17%      (0.19%)
- --------------------------------------------------------------------------------------------------------
10. Net assets, end of period (in millions)               $41       $48       $54       $76          $3
11. Average net assets for the period (in
    millions)                                             $42       $47       $60       $37          $1
12. Ratio of gross expenses to average net
    assets**                                             0.67%     0.66%      N/A       N/A         N/A
13. Ratio of net expenses to average net
    assets**                                             0.65%(2)  0.65%(2)  0.65%(2)  0.83%(2,3)  1.00%
14. Ratio of net investment income to average
    net assets**                                         5.57%     6.67%     6.08%     4.86%       3.22%
15. Portfolio turnover rate**                             486%      337%      346%      372%          7%
- --------------------------------------------------------------------------------------------------------
</TABLE>
    
 
   
(1) Fiscal period from September 1, 1992 (inception) to October 31, 1992.
    
   
(2) The ratio of net expenses to average net assets was   % in 1997, 1.23% in
    1996, 1.23% in 1995, 1.15% in 1994, 1.40% in 1993 and 2.50% in 1992 before
    waiver of certain Fund expenses.
    
   
(3) The ratio of net expenses to average net assets reflects the Fund's previous
    expense limit of 1.00%. This limit was reduced to .65% as of August 1, 1993.
    
   
 * Total return is not annualized for periods of less than one full year.
    
** Annualized for periods of less than one full year.
   
 + [To be filed by Amendment]
    
 
   
<TABLE>
<CAPTION>
                                                                                   JANUS
                                                        JANUS                 GOVERNMENT MONEY
                                                  MONEY MARKET FUND              MARKET FUND
                                              -------------------------   -------------------------
              INVESTOR SHARES                 1997+    1996     1995(1)   1997+   1996      1995(1)
<S>                                           <C>     <C>       <C>       <C>     <C>       <C>
- ---------------------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD              $1.00     $1.00             $1.00     $1.00
- ---------------------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income                               .05       .04               .05       .04
 3. Net gains or (losses) on securities
    (both realized and unrealized)                       --        --                --        --
- ---------------------------------------------------------------------------------------------------
 4. Total from investment operations                    .05       .04               .05       .04
- ---------------------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)             (.05)     (.04)             (.05)     (.04)
 6. Distributions (from capital gains)                   --        --                --        --
- ---------------------------------------------------------------------------------------------------
 7. Total distributions                                (.05)     (.04)             (.05)     (.04)
- ---------------------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                    $1.00     $1.00             $1.00     $1.00
- ---------------------------------------------------------------------------------------------------
 9. Total return*                                      5.13%     3.95%             5.03%     3.90%
- ---------------------------------------------------------------------------------------------------
10. Net assets, end of period (in millions)            $774      $643              $117      $119
11. Average net assets for the period (in
    millions)                                          $676      $461              $112       $87
12. Ratio of expenses to average net
    assets**                                           0.60%(2)  0.60%(2)          0.60%(2)  0.60%(2)
13. Ratio of net investment income to
    average net assets**                               5.01%     5.56%             4.91%     5.40%
- ---------------------------------------------------------------------------------------------------
</TABLE>
    
 
(1) Fiscal period from February 15, 1995 (inception) to October 31, 1995.
(2) The ratio of expenses to average net assets was 0.70% before voluntary
    reduction of fees.
 * Total return is not annualized for periods of less than one full year.
** Annualized for periods of less than one full year.
   
 + [To be filed by Amendment]
    
   
 10   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
   
<TABLE>
<CAPTION>
                                                                       JANUS
                                                                 TAX-EXEMPT MONEY
                                                                    MARKET FUND
                                                              -----------------------
                      INVESTOR SHARES                         1997+   1996    1995(1)
<S>                                                           <C>     <C>     <C>
- ----------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD                              $1.00     $1.00
- ----------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income                                               .03       .02
 3. Net gains or (losses) on securities (both realized and
    unrealized)                                                          --        --
- ----------------------------------------------------------------------------------------
 4. Total from investment operations                                    .03       .02
- ----------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)                             (.03)     (.02)
 6. Distributions (from capital gains)                                  --         --
- ----------------------------------------------------------------------------------------
 7. Total distributions                                                (.03)     (.02)
- ----------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                                    $1.00     $1.00
- ----------------------------------------------------------------------------------------
 9. Total return*                                                      3.27%     2.40%
- ----------------------------------------------------------------------------------------
10. Net assets, end of period (in millions)                             $75       $67
11. Average net assets for the period (in millions)                     $69       $57
12. Ratio of expenses to average net assets**                          0.60%(2)  0.60%(2)
13. Ratio of net investment income to average net assets**             3.22%     3.38%
- ----------------------------------------------------------------------------------------
</TABLE>
    
 
(1) Fiscal period from February 15, 1995 (inception) to October 31, 1995.
(2) The ratio of expenses to average net assets was 0.70% before voluntary
    reduction of fees.
 * Total return is not annualized for periods of less than one full year.
** Annualized for periods of less than one full year.
   
 + [To be filed by Amendment]
    
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    11
    
<PAGE>   
 
                               UNDERSTANDING THE
                              FINANCIAL HIGHLIGHTS
 
This section is designed to help you better understand the information
summarized in the Financial Highlights tables. The tables contain important
historical operating information that may be useful in making your investment
decision or understanding how your investment has performed. The Funds' Annual
Reports contain additional information about each Fund's performance, including
a comparison to an appropriate securities index. For a copy of your Fund's
Annual Report, call 1-800-525-8983.
 
NET ASSET VALUE ("NAV") is the value of a single share of a Fund. It is computed
by adding the value of all of a Fund's investments and other assets, subtracting
any liabilities and dividing the result by the number of shares outstanding. The
difference between line 1 and line 8 in the Financial Highlights tables
represents the change in value of a share of a Fund over the fiscal period, but
not its total return. The Money Market Funds' NAV is expected to be $1.00.
 
NET INVESTMENT INCOME is the per share amount of dividends and interest income
earned on securities held by a Fund, less Fund expenses. DIVIDENDS (FROM NET
INVESTMENT INCOME) are the per share amount that a Fund paid from net investment
income.
 
NET GAINS OR (LOSSES) ON SECURITIES is the per share increase or decrease in
value of the securities a Fund holds. A gain (or loss) is realized when
securities are sold. A gain (or loss) is unrealized when securities increase or
decrease in value but are not sold. DISTRIBUTIONS (FROM CAPITAL GAINS) are the
per share amount that a Fund paid from net realized gains.
 
TOTAL RETURN is the percentage increase or decrease in the value of an
investment over a stated period of time. A total return percentage includes both
changes in NAV and income. For the purposes of calculating total return, it is
assumed that dividends and distributions are reinvested at the NAV on the day of
the distribution. A FUND'S TOTAL RETURN CANNOT BE COMPUTED DIRECTLY FROM THE
FINANCIAL HIGHLIGHTS TABLES.
 
   
RATIO OF GROSS EXPENSES TO AVERAGE NET ASSETS is the total of a Fund's operating
expenses before expense offset arrangements divided by its average net assets
for the stated period. RATIO OF NET EXPENSES TO AVERAGE NET ASSETS reflects
reductions in a Fund's expenses through the use of brokerage commissions and
uninvested cash balances earning interest or balance credits.
    
 
RATIO OF NET INVESTMENT INCOME TO AVERAGE NET ASSETS is a Fund's net investment
income divided by its average net assets for the stated period.
 
PORTFOLIO TURNOVER RATE is a measure of the amount of a fund's buying and
selling activity. It is computed by dividing total purchases or sales, whichever
is less, by the average monthly market value of a fund's portfolio securities.
The Money Market Funds do not calculate portfolio turnover.
 
   
 12   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
                                THE FIXED-INCOME
                                FUNDS IN DETAIL
 
   
This section takes a closer look at the Funds' investment objectives, policies
and the securities in which they invest. Policies that are noted as
"fundamental" cannot be changed without a shareholder vote. All other policies,
including each Fund's investment objective, are not fundamental and may be
changed by the Funds' Trustees without a shareholder vote. You will be notified
of any material changes.
    
 
   
You should carefully consider your own investment goals, time horizon (the
amount of time you plan to hold your shares of a Fund) and risk tolerance before
investing in a Fund. If there is a material change in a Fund's objective or
policies, you should consider whether that Fund remains an appropriate
investment for you. There is no guarantee that any Fund will meet its investment
objective.
    
 
   
You should also carefully review the "Additional Risk Factors" section of this
Prospectus for a more detailed discussion of the risk associated with certain
investment techniques. Appendix A includes more detailed descriptions of
investment terms used throughout this Prospectus.
    
 
- --------------------------------------------------------------------------------
 
FIXED-INCOME FUNDS
Investment Objective:
  Janus Flexible Income Fund........................................Total Return
  Others..................................................................Income
Primary Holdings:....................................Income-Producing Securities
Shareholder's Investment Horizon:
  Janus Short-Term Bond Fund.........................Short- to Intermediate-Term
  Others..............................................Intermediate- to Long-Term
 
- --------------------------------------------------------------------------------
 
JANUS FLEXIBLE INCOME FUND
The investment objective of this Fund is to obtain maximum total return,
consistent with preservation of capital. This Fund pursues its objective
primarily through investments in income-producing securities. Total return is
expected to result from a combination of current income and capital
appreciation, although income will normally be the dominant component of total
return. As a fundamental policy, this Fund will invest at least 80% of its
assets in income-producing securities.
 
Janus Flexible Income Fund may invest in a wide variety of income-producing
securities including corporate bonds and notes, government securities,
indexed/structured securities, preferred stock, income-producing common stocks,
debt securities that are convertible or exchangeable into equity securities, and
debt securities that carry with them the right to acquire equity securities as
evidenced by warrants attached to or acquired with the securities. The Fund may
invest to a lesser degree in common stocks, other equity securities or debt
securities that are not currently paying dividends or
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    13
    
<PAGE>   
 
interest. The Fund may purchase securities of any maturity and quality and the
average maturity and quality of its portfolio may vary substantially.
 
   
Janus Flexible Income Fund may invest without limit in foreign securities,
including those of corporate and government issuers. The Fund may invest without
limit in high-yield/high-risk securities and may have substantial holdings of
such securities. The Fund may invest without limit in mortgage- and asset-backed
securities and in zero coupon, pay-in-kind and step coupon securities. The risks
of foreign securities and high-yield securities are described under "Additional
Risk Factors" on pages 20-23.
    
 
The Fund may purchase defaulted debt securities if, in the opinion of Janus
Capital, it appears likely that the issuer may resume interest payments or other
advantageous developments appear likely in the near term. Defaulted debt
securities may be illiquid and subject to the Fund's limit on illiquid
investments.
 
JANUS HIGH-YIELD FUND
   
The primary investment objective of this Fund is to obtain high current income.
Capital appreciation is a secondary objective when consistent with its primary
objective. Capital appreciation may result, for example, from an improvement in
the credit standing of an issuer whose securities are held by this Fund or from
a general lowering of interest rates, or both. This Fund pursues its objectives
by investing primarily in high-yield/high-risk fixed-income securities. This
Fund will normally invest at least 65% of its total assets in those securities.
In addition, the Fund may invest in all of the types of securities previously
described under Janus Flexible Income Fund.
    
 
   
The high yields sought by this Fund are expected to result primarily from
investments in longer-term, lower quality corporate bonds, commonly referred to
as "junk" bonds. This Fund considers lower quality securities to be securities
rated below investment grade by established rating agencies or unrated
securities of comparable quality. Securities rated BB or lower by Standard &
Poor's Ratings Services ("Standard & Poor's") or Ba or lower by Moody's
Investors Service, Inc. ("Moody's") are below investment grade. Lower quality
securities are often considered to be more speculative and involve greater risk
of default or price changes due to changes in interest rates, economic
conditions and the issuer's credit-worthiness. As a result, their market prices
tend to fluctuate more than higher quality securities of comparable maturity.
Additional risks of lower quality securities are described under "Additional
Risk Factors" on pages 20-23.
    
 
JANUS FEDERAL TAX-EXEMPT FUND
The investment objective of this Fund is to seek as high a level of current
income exempt from federal income tax as is consistent with preservation of
capital. This Fund pursues its objective by investing primarily in municipal
obligations of any maturity whose interest is exempt from federal income tax.
Because of this emphasis, capital appreciation is not a significant investment
consideration. However, to the extent that capital gains are realized, they are
subject to federal income tax. As a fundamental policy, this Fund will normally
invest at least 80% of its net assets in securities whose interest is exempt
from federal income tax, including the federal alternative minimum
 
   
 14   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
tax. The Fund is designed for investors who seek a higher after-tax yield than
comparable investing in taxable securities.
 
Municipal securities in which the Fund may invest include general obligation
bonds, revenue bonds, industrial development bonds, municipal lease obligations,
certificates of participation (not to exceed 10% of assets), inverse floaters
(not to exceed 5% of assets), instruments with demand features, tender option
bonds and standby commitments.
 
At times, this Fund may invest more than 25% of its assets in tax-exempt
securities that are related in such a way that an economic, business, or
political development or change affecting one security could similarly affect
the other securities; for example, securities whose issuers are located in the
same state, or securities whose interest is derived from revenues of similar
type projects. The Fund may invest more than 25% of its assets in industrial
development bonds.
 
Subject to the policies above, the Fund may invest up to 25% of its assets in
mortgage-and asset-backed securities and up to 10% of its assets in zero coupon,
pay-in-kind and step coupon securities. The Fund will invest less than 35% of
its net assets in high-yield/high-risk securities.
 
JANUS SHORT-TERM BOND FUND
The investment objective of this Fund is to seek as high a level of current
income as is consistent with preservation of capital. This Fund pursues its
objective by investing primarily in short- and intermediate-term fixed-income
securities. Under normal circumstances, it is expected that this Fund's
dollar-weighted average portfolio effective maturity will not exceed three
years.
 
Effective maturity is the weighted average period over which a security's
principal is expected to be paid. It differs from stated maturity in that it
estimates the effect of expected principal prepayments and call provisions.
Targeting effective maturity provides additional flexibility in portfolio
management but, all else being equal, could result in higher volatility than a
fund targeting a stated maturity or maturity range. See the question and answer
section below for a more detailed discussion of the Fund's maturity policy.
 
   
Janus Short-Term Bond Fund will normally invest at least 65% of its assets in
debt securities. Subject to this policy and subject to its maturity limits, the
Fund may invest in the types of securities previously described under Janus
Flexible Income Fund except that the Fund will invest less than 35% of its net
assets in high-yield/high-risk securities, its investments in mortgage- and
asset-backed securities will not exceed 25% of assets and its investments in
zero coupon, pay-in-kind and step coupon securities will not exceed 10% of
assets.
    
 
FIXED-INCOME FUNDS
   
Each Fund may purchase securities on a when-issued, delayed delivery or forward
commitment basis. In addition, each Fund may use futures, options, swaps and
other derivatives for hedging purposes or for non-hedging purposes such as
seeking to enhance return. See "Additional Risk Factors" on pages 20-23. When
its portfolio manager is
    
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    15
    
<PAGE>   
 
   
unable to locate investment opportunities with favorable risk/reward
characteristics, the cash position of any Fund may increase and the Fund may
have substantial holdings of cash or cash equivalent short-term obligations. See
"General Portfolio Policies" on page 18.
    
 
THE FOLLOWING QUESTIONS ARE DESIGNED TO HELP YOU BETTER UNDERSTAND AN INVESTMENT
IN THE JANUS FIXED-INCOME FUNDS.
 
Q    HOW DO INTEREST RATES AFFECT THE
     VALUE OF MY INVESTMENT?
A:   A fundamental risk associated with any fund that invests in fixed-income
     securities (e.g., a bond fund) is the risk that the value of the securities
     it holds will rise or fall as interest rates change. Generally, a
fixed-income security will increase in value when interest rates fall and
decrease in value when interest rates rise. Longer-term securities are generally
more sensitive to interest rate changes than shorter-term securities, but they
generally offer higher yields to compensate investors for the associated risks.
A bond fund's average-weighted effective maturity and its duration are measures
of how the fund may react to interest rate changes. High-yield bond prices are
generally less directly responsive to interest rate changes than investment
grade issues and may not always follow this pattern.
     
 
Q:   WHAT IS MEANT BY A FUND'S
     "AVERAGE-WEIGHTED EFFECTIVE MATURITY"?
A:   The stated maturity of a bond is the date when the issuer must repay the
     bond's entire principal value to an investor, such as a Fund. Some types of
     bonds, such as mortgage-backed securities and securities with call
provisions, may also have an "effective maturity" that is shorter than the
stated date. With respect to GNMA securities and other mortgage-backed
securities, effective maturity is likely to be substantially less than the
stated maturities of the mortgages in the underlying pools. With respect to
obligations with call provisions, effective maturity is typically the next call
date on which the obligation reasonably may be expected to be called. Securities
without prepayment or call provisions generally have an effective maturity equal
to their stated maturity. Dollar-weighted effective maturity is calculated by
averaging the effective maturity of bonds held by a Fund with each effective
maturity "weighted" according to the percentage of net assets that it
represents.
 
     
 
Q:   WHAT IS MEANT BY A FUND'S "DURATION"?
 
A:   A bond's duration indicates the time it will take an investor to recoup 
     his investment. Unlike average maturity, duration reflects both principal 
     and interest payments. Generally, the higher the coupon rate on a bond, the
lower its duration will be. The duration of a bond fund is calculated by
averaging the duration of bonds held by a fund with each duration "weighted"
according to the percentage of net assets that it represents. Because duration
accounts for interest payments, a Fund's duration is usually shorter than its
average maturity.
 
     
 
   
 16   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   

   
Q:  HOW DO THE FIXED-INCOME FUNDS
    MANAGE INTEREST RATE RISK?
    
     

   
A:  Each Fixed-Income Fund may vary the average-weighted effective 
    maturity of its portfolio to reflect its portfolio manager's analysis of 
    interest rate trends and other factors. A Fund's average-weighted effective 
maturity will tend to be shorter when its portfolio manager expects interest 
rates to rise and longer when its portfolio manager expects interest rates to 
fall. The Funds may also use futures, options and other derivatives to manage 
interest rate risk. See "Additional Risk Factors" on pages 20-23.
    
 
Q:  WHAT IS MEANT BY "CREDIT QUALITY"?
 
 
A:  Credit quality measures the likelihood that the issuer will meet its
    obligations on a bond. One of the fundamental risks associated with all
    fixed-income funds is credit risk, which is the risk that an issuer will be
unable to make principal and interest payments when due. U.S. government
securities are generally considered to be the safest type of investment in terms
of credit risk. Municipal obligations generally rank between U.S. government
securities and corporate debt securities in terms of credit safety. Corporate
debt securities, particularly those rated below investment grade, present the
highest credit risk.
     
 
Q:  HOW IS CREDIT QUALITY MEASURED?
 
A:  Ratings published by nationally recognized statistical rating agencies 
    such as Standard & Poor's and Moody's are widely accepted measures of 
    credit risk. The lower a bond issue is rated by an agency, the more credit 
risk it is considered to represent. Lower rated bonds generally pay higher 
yields to compensate investors for the associated risk. Please refer to Appendix
B for a description of rating categories.
 
     
 
Q:  WHAT IS A HIGH-YIELD/HIGH-RISK SECURITY?
 
A:  A high-yield security (also called a "junk" bond) is a debt security rated
    below investment grade by major rating agencies (i.e., BB or lower by
    Standard & Poor's or Ba or lower by Moody's) or an unrated bond of similar
quality. It presents greater risk of default (the failure to make timely
interest and principal payments) than higher quality bonds.
 
 
     
   
Q:   WHAT RISKS DO HIGH-YIELD/HIGH-RISK
     SECURITIES PRESENT?
    
     
   
A:   High-yield securities are often considered to be more speculative and
     involve greater risk of default or price changes due to changes in economic
     and industry conditions and the issuer's creditworthiness. Their market
prices tend to fluctuate more than higher quality securities as a result of
changes in these factors.
    
   
 
The default rate of lower quality debt securities is likely to be higher when
issuers have difficulty meeting projected goals or obtaining additional
financing. This could occur during economic recessions or periods of high
interest rates. In addition, there may be a smaller market for lower quality
securities than for higher quality securities, making lower quality securities
more difficult to sell promptly at an acceptable price.
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    17
    
<PAGE>   
 
The junk bond market can experience sudden and sharp price swings. Because Janus
Flexible Income Fund and Janus High-Yield Fund may invest a significant portion
of their portfolios in high-yield/high-risk securities, investors in such Funds
should be willing to tolerate a corresponding increase in the risk of
significant and sudden changes in NAV.
 
   
Q:   WHAT ARE THE TAX ADVANTAGES OF INVESTING IN
     JANUS FEDERAL TAX-EXEMPT FUND?
    
   
A:   Most regular income dividends you receive from Janus Federal Tax-Exempt
     Fund generally will not be subject to federal income tax. Additionally,
     your state may not tax the portion of this Fund's income derived from
obligations issued by your state (if any). Capital gains distributed by this
Fund are taxable to you. See "Distributions" and "Taxes" on pages 47-49. The
higher your income tax level is, the more you will benefit from tax-exempt
investing.

    
 
Q:   HOW DO THE FIXED-INCOME FUNDS
     DIFFER FROM EACH OTHER?
A:   The chart below shows that the Fixed-Income Funds differ substantially in
     terms of the type, credit quality and interest rate risk of the securities
     in which they invest.
 
     
 
<TABLE>
<CAPTION>
                                    PRIMARY                       INTEREST RATE
                                INVESTMENT TYPE     CREDIT RISK       RISK
- -------------------------------------------------------------------------------
<S>                           <C>                   <C>           <C>
Janus Flexible Income Fund    Corporate Bonds        High          High
Janus High-Yield Fund         Corporate Bonds        Highest       Moderate
Janus Federal Tax-Exempt Fund Municipal Securities   Moderate      High
Janus Short-Term Bond Fund    Corporate Bonds        Moderate      Low
</TABLE>
 
GENERAL PORTFOLIO POLICIES
Unless otherwise stated, each of the following policies applies to all of the
Fixed-Income Funds. The percentage limitations included in these policies and
elsewhere in this Prospectus apply at the time of purchase of the security. For
example, if a Fund exceeds a limit as a result of market fluctuations or the
sale of other securities, it will not be required to dispose of any securities.
 
CASH POSITION
When a Fixed-Income Fund's portfolio manager believes that market conditions are
not favorable for profitable investing or when the portfolio manager is
otherwise unable to locate favorable investment opportunities, the Fund's
investments may be hedged to a greater degree and/or its cash or similar
investments may increase. In other words, the Fixed-Income Funds do not always
stay fully invested in stocks and bonds. Cash or similar investments are a
residual - they represent the assets that remain after a portfolio manager has
committed available assets to desirable investment opportunities. Partly because
the portfolio managers act independently of each other, the cash positions of
the Fixed-Income Funds may vary significantly. Larger hedged positions and/or
larger cash positions may serve as a means of preserving capital in unfavorable
market conditions.
 
Securities that the Fixed-Income Funds may invest in as a means of receiving a
return on idle cash include high-grade commercial paper, certificates of
deposit, repurchase
 
   
 18   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
   
agreements or other short-term debt obligations. The Fixed-Income Funds may also
invest in money market funds (including funds managed by Janus Capital). Janus
Federal Tax-Exempt Fund may invest in such securities even though they may be
federally taxable. When a Fixed-Income Fund is hedged or its investments in cash
or similar investments increase, it may not participate in stock or bond market
advances or declines to the same extent that it would if the Fund was not hedged
or remained more fully invested in stocks or bonds.
    
 
DIVERSIFICATION
The Investment Company Act of 1940 (the "1940 Act") classifies investment
companies as either diversified or nondiversified. All of the Fixed-Income Funds
qualify as diversified funds under the 1940 Act. The Fixed-Income Funds are
subject to the following diversification requirements:
 
- - As a fundamental policy, no Fixed-Income Fund may own more than 10% of the
  outstanding voting shares of any issuer.
 
- - As a fundamental policy, with respect to 75% of the total assets of each
  Fixed-Income Fund, no Fund will purchase a security of any issuer (other than
  cash items and U.S. government securities, as defined in the 1940 Act) if such
  purchase would cause the Fund's holdings of that issuer to amount to more than
  5% of that Fund's total assets.
 
- - No Fund will invest more than 25% of its total assets in a single issuer
  (other than U.S. government securities).
 
INDUSTRY CONCENTRATION
As a fundamental policy, no Fixed-Income Fund will invest 25% or more of its
total assets in any particular industry (excluding U.S. government securities
and municipal obligations issued by governments or their subdivisions because
the issuers of those securities are not considered a part of any industry).
 
PORTFOLIO TURNOVER
Each Fixed-Income Fund generally intends to purchase securities for long-term
investment rather than short-term gains. However, short-term transactions may
result from liquidity needs, securities having reached a price or yield
objective, changes in interest rates or the credit standing of an issuer, or by
reason of economic or other developments not foreseen at the time of the initial
investment decision. Changes are made in a Fixed-Income Fund's portfolio
whenever its portfolio manager believes such changes are desirable. Portfolio
turnover rates are generally not a factor in making buy and sell decisions.
 
   
To a limited extent, a Fixed-Income Fund may purchase securities in anticipation
of relatively short-term price gains. A Fixed-Income Fund may also sell one
security and simultaneously purchase the same or a comparable security to take
advantage of short-term differentials in bond yields or securities prices.
Increased portfolio turnover may result in higher costs for brokerage
commissions, dealer mark-ups and other transaction costs and may also result in
taxable capital gains.
    
 
ILLIQUID INVESTMENTS
Each Fixed-Income Fund may invest up to 15% of its net assets in illiquid
investments, including restricted securities or private placements that are not
deemed to be liquid by
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    19
    
<PAGE>   
 
   
Janus Capital. If illiquid securities exceed 15% of a Fund's net assets after
the time of purchase, the Fund will take steps to reduce in an orderly fashion
its holdings of illiquid securities. An illiquid investment is a security or
other position that cannot be disposed of quickly in the normal course of
business. Some securities cannot be sold to the U.S. public because of their
terms or because of SEC regulations. Janus Capital will follow guidelines
established by the Funds' Trustees in making liquidity determinations for Rule
144A securities and certain other securities, including privately placed
commercial paper and municipal lease obligations.
    
 
BORROWING AND LENDING
Each Fixed-Income Fund may borrow money and lend securities or other assets, as
follows:
 
- - Each Fixed-Income Fund may borrow money for temporary or emergency purposes in
  amounts up to 25% of its total assets.
 
   
- - Each Fixed-Income Fund may mortgage or pledge securities as collateral for
  borrowings in amounts up to 15% of its net assets.
    
 
- - As a fundamental policy, each Fixed-Income Fund may lend securities or other
  assets if, as a result, no more than 25% of its total assets would be lent to
  other parties.
 
   
Under the terms of an exemptive order received from the SEC, the Fixed-Income
Funds may borrow money from or lend money to each other and other funds that
permit such transactions and for which Janus Capital serves as investment
adviser. All such borrowing and lending will be subject to the above percentage
limits.
    
 
ADDITIONAL RISK FACTORS
HIGH-YIELD/HIGH-RISK SECURITIES
High-yield/high-risk securities (or "junk" bonds) are debt securities rated
below investment grade by the primary rating agencies (such as Standard & Poor's
and Moody's). Please refer to Appendix B for a description of rating categories.
 
The value of lower quality securities generally is more dependent on the ability
of the issuer to meet interest and principal payments (i.e., credit risk) than
is the case for higher quality securities. Conversely, the value of higher
quality securities may be more sensitive to interest rate movements than lower
quality securities. Issuers of high-yield securities may not be as strong
financially as those issuing bonds with higher credit ratings. Investments in
such companies are considered to be more speculative than higher quality
investments.
 
Issuers of high-yield securities are more vulnerable to real or perceived
economic changes (for instance, an economic downturn or prolonged period of
rising interest rates), political changes or adverse developments specific to
the issuer. Adverse economic, political or other developments may impair the
issuer's ability to service principal and interest obligations, to meet
projected business goals and to obtain additional financing, particularly if the
issuer is highly leveraged. In the event of a default, a Fixed-Income Fund would
experience a reduction of its income and could expect a decline in the market
value of the defaulted securities.
 
   
 20   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
The market for lower quality securities is generally less liquid than the market
for higher quality securities. Adverse publicity and investor perceptions as
well as new or proposed laws may also have a greater negative impact on the
market for lower quality securities. Unrated debt, while not necessarily of
lower quality than rated securities, may not have as broad a market as rated
securities. Sovereign debt of foreign governments is generally rated by country.
Because these ratings do not take into account individual factors relevant to
each issue and may not be updated regularly, Janus Capital may treat such
securities as unrated debt.
 
The market prices of high-yield securities structured as zero coupon or
pay-in-kind securities are generally affected to a greater extent by interest
rate changes and tend to be more volatile than securities which pay interest
periodically. In addition, zero coupon, pay-in-kind and delayed interest bonds
often do not pay interest until maturity. However, the Fixed-Income Funds must
recognize a computed amount of interest income and pay dividends to shareholders
even though they have received no cash. In some instances, the Fixed-Income
Funds may have to sell securities to have sufficient cash to pay the dividends.
 
FOREIGN SECURITIES
   
Investments in foreign securities, including those of foreign governments, may
involve greater risks than investing in comparable domestic securities.
Securities of some foreign companies and governments may be traded in the United
States, but many foreign securities are traded primarily in foreign markets. The
risks of foreign investing include:
    
 
- - CURRENCY RISK. A Fixed-Income Fund may buy the local currency when it buys a
  foreign currency denominated security and sell the local currency when it
  sells the security. As long as a Fund holds a foreign denominated security,
  its value will be affected by the value of the local currency relative to the
  U.S. dollar. When a Fund sells a foreign denominated security, its value may
  be worth less in U.S. dollars even though the security increases in value in
  its home country. U.S. dollar denominated securities of foreign issuers may
  also be affected by currency risk.
 
- - POLITICAL AND ECONOMIC RISK. Foreign investments may be subject to heightened
  political and economic risks, particularly in underdeveloped or developing
  countries which may have relatively unstable governments and economies based
  on only a few industries. In some countries, there is the risk that the
  government may take over the assets or operations of a company or that the
  government may impose taxes or limits on the removal of a Fixed-Income Fund's
  assets from that country. The Fixed-Income Funds may invest in emerging market
  countries. Emerging market countries involve greater risks such as immature
  economic structures, national policies restricting investments by foreigners,
  and different legal systems.
 
- - REGULATORY RISK. There may be less government supervision of foreign markets.
  Foreign issuers may not be subject to the uniform accounting, auditing and
  financial reporting standards and practices applicable to domestic issuers.
  There may be less publicly available information about foreign issuers than
  domestic issuers.
 
- - MARKET RISK. Foreign securities markets, particularly those of underdeveloped
  or developing countries, may be less liquid and more volatile than domestic
  markets. Certain markets may require payment for securities before delivery
  and delays may be
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    21
    
<PAGE>   
 
  encountered in settling securities transactions. In some foreign markets,
  there may not be protection against failure by other parties to complete
  transactions. There may be limited legal recourse against an issuer in the
  event of a default on a debt instrument.
 
- - TRANSACTION COSTS. Transaction costs of buying and selling foreign securities,
  including brokerage, tax and custody costs, are generally higher than those
  involved in domestic transactions.
 
Foreign securities purchased indirectly (e.g., depositary receipts) are subject
to many of the above risks, including currency risk, because their values depend
on the performance of a foreign security denominated in its home currency.
 
FUTURES, OPTIONS AND OTHER DERIVATIVE INSTRUMENTS
Each Fixed-Income Fund may enter into futures contracts on securities, financial
indices and foreign currencies and options on such contracts ("futures
contracts") and may invest in options on securities, financial indices and
foreign currencies ("options"), forward contracts and interest rate swaps and
swap-related products (collectively "derivative instruments"). The Fixed-Income
Funds intend to use most derivative instruments primarily to hedge the value of
their portfolios against potential adverse movements in securities prices,
foreign currency markets or interest rates. To a limited extent, the
Fixed-Income Funds may also use derivative instruments for non-hedging purposes
such as seeking to increase income or otherwise seeking to enhance return.
Please refer to Appendix A to this Prospectus and the SAI for a more detailed
discussion of these instruments.
 
The use of derivative instruments exposes the Fixed-Income Funds to additional
investment risks and transaction costs. Risks inherent in the use of derivative
instruments include:
 
- - the risk that interest rates, securities prices and currency markets will not
  move in the direction that a portfolio manager anticipates;
 
- - imperfect correlation between the price of derivative instruments and
  movements in the prices of the securities, interest rates or currencies being
  hedged;
 
- - the fact that skills needed to use these strategies are different from those
  needed to select portfolio securities;
 
- - inability to close out certain hedged positions to avoid adverse tax
  consequences;
 
- - the possible absence of a liquid secondary market for any particular
  instrument and possible exchange-imposed price fluctuation limits, either of
  which may make it difficult or impossible to close out a position when
  desired;
 
- - leverage risk, that is, the risk that adverse price movements in an instrument
  can result in a loss substantially greater than a Fixed-Income Fund's initial
  investment in that instrument (in some cases, the potential loss is
  unlimited); and
 
- - particularly in the case of privately-negotiated instruments, the risk that
  the counterparty will fail to perform its obligations, which could leave a
  Fixed-Income Fund worse off than if it had not entered into the position.
 
   
 22   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
Although the Fixed-Income Funds believe the use of derivative instruments will
benefit the Funds, a Fund's performance could be worse than if the Fund had not
used such instruments if a portfolio manager's judgement proves incorrect.
 
When a Fixed-Income Fund invests in a derivative instrument, it may be required
to segregate cash and other liquid assets or certain portfolio securities with
its custodian to "cover" the Fund's position. Assets segregated or set aside
generally may not be disposed of so long as the Fund maintains the positions
requiring segregation or cover. Segregating assets could diminish the Fund's
return due to the opportunity losses of foregoing other potential investments
with the segregated assets.
 
SHORT SALES
   
Each Fixed-Income Fund may engage in "short sales against the box." This
technique involves selling either a security that a Fund owns, or a security
equivalent in kind and amount to the security sold short that the Fund has the
right to obtain, for delivery at a specified date in the future. A Fund may
enter into a short sale against the box to hedge against anticipated declines in
the market price of portfolio securities. If the value of the securities sold
short increases prior to the scheduled delivery date, a Fund loses the
opportunity to participate in the gain.
    
 
SPECIAL SITUATIONS
Each Fixed-Income Fund may invest in "special situations" from time to time. A
special situation arises when, in the opinion of a Fund's portfolio manager, the
securities of a particular issuer will be recognized and appreciate in value due
to a specific development with respect to that issuer. Developments creating a
special situation might include, among others, a new product or process, a
technological breakthrough, a management change or other extraordinary corporate
event, or differences in market supply of and demand for the security.
Investment in special situations may carry an additional risk of loss in the
event that the anticipated development does not occur or does not attract the
expected attention.
 
See Appendix A for risks associated with certain other investments.
 
                             THE MONEY MARKET FUNDS
                                   IN DETAIL
 
INVESTMENT OBJECTIVES
The investment objective of each of Janus Money Market Fund and Janus Government
Money Market Fund is to seek maximum current income to the extent consistent
with stability of capital. The investment objective of Janus Tax-Exempt Money
Market Fund is to seek maximum current income that is exempt from federal income
taxes to the extent consistent with stability of capital. There can be no
assurance that a Fund will achieve its investment objective or that the Shares
will be able to maintain a stable net asset value of $1.00 per share.
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    23
    
<PAGE>   
 
COMMON INVESTMENT POLICIES
The Money Market Funds will invest only in eligible high quality, short-term
money market instruments that present minimal credit risks, as determined by
Janus Capital, pursuant to procedures adopted by the Trustees. Each Money Market
Fund may invest only in U.S. dollar-denominated instruments that have a
remaining maturity of 397 days or less (as calculated pursuant to Rule 2a-7
under the 1940 Act) and will maintain a dollar-weighted average portfolio
maturity of 90 days or less.
 
Except to the limited extent permitted by Rule 2a-7 and except for U.S.
Government Securities (as defined below), each Money Market Fund will not invest
more than 5% of its total assets in the securities of any one issuer. A
guarantor is not considered an issuer for the purpose of this limit provided
that the value of all securities held by a Money Market Fund that are issued or
guaranteed by that institution does not exceed 10% of the Money Market Fund's
total assets. Until pending amendments to Rule 2a-7 become effective, up to 25%
of Janus Tax-Exempt Money Market Fund's total assets may be invested without
regard to the foregoing limitations. A Money Market Fund may not invest more
than 25% of its total assets in any one industry, except that this limit does
not apply to U.S. Government Securities, bank obligations or municipal
securities. To ensure adequate liquidity, no Money Market Fund may invest more
than 10% of its net assets in illiquid investments, including repurchase
agreements maturing in more than seven days (unless subject to a demand feature)
and certain time deposits that are subject to early withdrawal penalties and
mature in more than seven days. Because the Money Market Funds are typically
used as a cash management vehicle, they intend to maintain a high degree of
liquidity. Janus Capital determines and monitors the liquidity of portfolio
securities under the supervision of the Trustees.
 
RATINGS
High quality money market instruments include those that (i) are rated (or, if
unrated, are issued by an issuer with comparable outstanding short-term debt
that is rated) in one of the two highest rating categories for short-term debt
by any two nationally recognized statistical rating organizations ("NRSROs") or,
if only one NRSRO has issued a rating, by that NRSRO or (ii) are otherwise
unrated and determined by Janus Capital to be of comparable quality. Each Money
Market Fund, except Janus Tax-Exempt Money Market Fund, will invest at least 95%
of its total assets in securities in the highest rating category (as determined
pursuant to Rule 2a-7). Descriptions of the rating categories of Standard &
Poor's, Moody's, and certain other NRSROs are contained in Appendix B. A further
description of the Money Market Funds' investment policies is included in the
Money Market Funds' SAI.
 
Although each Money Market Fund only invests in high quality money market
instruments, an investment in a Money Market Fund is subject to risk even if all
securities in a Money Market Fund's portfolio are paid in full at maturity. All
money market instruments, including U.S. Government Securities, can change in
value as a result of changes in interest rates, the issuer's actual or perceived
creditworthiness or the issuer's ability to meet its obligations.
 
   
 24   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
TYPES OF INVESTMENTS
 
JANUS MONEY MARKET FUND
Janus Money Market Fund pursues its objective by investing primarily in high
quality debt obligations and obligations of financial institutions. The Fund may
also invest in U.S. Government Securities (as defined below) and municipal
securities, although the Fund expects to invest in such securities to a lesser
degree.
 
DEBT OBLIGATIONS
The Fund may invest in debt obligations of domestic issuers, including
commercial paper (short-term promissory notes issued by companies to finance
their, or their affiliates' current obligations), notes and bonds, and variable
amount master demand notes. The payment obligations on these instruments may be
backed by securities, swap agreements or other assets, by a guarantee of a third
party or solely by the unsecured promise of the issuer to make payments when
due. The Fund may invest in privately issued commercial paper or other
securities that are restricted as to disposition under the federal securities
laws. In general, sales of these securities may not be made absent registration
under the Securities Act of 1933 (the "1933 Act") or the availability of an
appropriate exemption. Pursuant to Section 4(2) of the 1933 Act or Rule 144A
adopted under the 1933 Act, however, some of these securities are eligible for
resale to institutional investors, and accordingly, Janus Capital may determine
that a liquid market exists for such a security pursuant to guidelines adopted
by the Trustees.
 
OBLIGATIONS OF FINANCIAL INSTITUTIONS
   
The Fund may invest in obligations of financial institutions. Examples of
obligations in which the Fund may invest include negotiable certificates of
deposit, bankers' acceptances, time deposits and other obligations of U.S. banks
(including savings and loan associations) having total assets in excess of one
billion dollars and U.S. branches of foreign banks having total assets in excess
of ten billion dollars. The Fund may also invest in Eurodollar and Yankee bank
obligations as discussed below and other U.S. dollar-denominated obligations of
foreign banks having total assets in excess of ten billion dollars that Janus
Capital believes are of an investment quality comparable to obligations of U.S.
banks in which the Fund may invest.
    
 
Certificates of deposit represent an institution's obligation to repay funds
deposited with it that earn a specified interest rate over a given period.
Bankers' acceptances are negotiable obligations of a bank to pay a draft which
has been drawn by a customer and are usually backed by goods in international
trade. Time deposits are non-negotiable deposits with a banking institution that
earn a specified interest rate over a given period. Fixed time deposits, which
are payable at a stated maturity date and bear a fixed rate of interest,
generally may be withdrawn on demand by the Fund but may be subject to early
withdrawal penalties that could reduce the Fund's yield. Unless there is a
readily available market for them, time deposits that are subject to early
withdrawal penalties and that mature in more than seven days will be treated as
illiquid securities.
 
   
Eurodollar bank obligations are dollar-denominated certificates of deposit or
time deposits issued outside the U.S. capital markets by foreign branches of
U.S. banks and by foreign banks. Yankee bank obligations are dollar-denominated
obligations issued in the U.S. capital markets by foreign banks.
    
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    25
    
<PAGE>   
 
   
Foreign, Eurodollar (and to a limited extent, Yankee) bank obligations are
subject to certain sovereign risks. One such risk is the possibility that a
foreign government might prevent dollar-denominated funds from flowing across
its borders. Other risks include: adverse political and economic developments in
a foreign country; the extent and quality of government regulation of financial
markets and institutions; the imposition of foreign withholding taxes; and
expropriation or nationalization of foreign issuers.
    
 
U.S. GOVERNMENT SECURITIES
The Fund may invest without limit in U.S. Government Securities as described
below under "Janus Government Money Market Fund."
 
MUNICIPAL SECURITIES
The Fund may invest in obligations of states, territories or possessions of the
United States and their subdivisions, authorities and corporations as described
below under "Janus Tax-Exempt Money Market Fund." These obligations may pay
interest that is exempt from federal income taxation.
 
JANUS GOVERNMENT MONEY MARKET FUND
Janus Government Money Market Fund pursues its objective by investing
exclusively in obligations issued and/or guaranteed as to principal and interest
by the United States government or by its agencies and instrumentalities and
repurchase agreements secured by such obligations.
 
U.S. GOVERNMENT SECURITIES
U.S. Government Securities shall have the meaning set forth in the 1940 Act. The
1940 Act defines U.S. Government Securities to include securities issued or
guaranteed by the U.S. government, its agencies and instrumentalities. U.S.
Government Securities may also include repurchase agreements collateralized by
and municipal securities escrowed with or refunded with U.S. government
securities. U.S. Government Securities in which the Fund may invest include U.S.
Treasury securities and obligations issued or guaranteed by U.S. government
agencies and instrumentalities that are backed by the full faith and credit of
the U.S. government, such as those guaranteed by the Small Business
Administration or issued by the Government National Mortgage Association. In
addition, U.S. Government Securities in which the Fund may invest include
securities supported primarily or solely by the creditworthiness of the issuer,
such as securities of the Federal National Mortgage Association, the Federal
Home Loan Mortgage Corporation and the Tennessee Valley Authority. There is no
guarantee that the U.S. government will support securities not backed by its
full faith and credit. Accordingly, although these securities have historically
involved little risk of loss of principal if held to maturity, they may involve
more risk than securities backed by the full faith and credit of the U.S.
government.
 
JANUS TAX-EXEMPT MONEY MARKET FUND
Janus Tax-Exempt Money Market Fund pursues its objective by investing primarily
in municipal securities whose interest is exempt from federal income taxes,
including the federal alternative minimum tax. Although the Fund will attempt to
invest substantially all of its assets in municipal securities whose interest is
exempt from federal income taxes, the Fund reserves the right to invest up to
20% of its net assets in securities
 
   
 26   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
whose interest is federally taxable. Additionally, when its portfolio manager is
unable to locate investment opportunities with desirable risk/reward
characteristics, the Fund may invest without limit in cash and cash equivalents,
including obligations that may be federally taxable (See "Taxable Investments").
 
MUNICIPAL SECURITIES
The municipal securities in which the Fund may invest include municipal notes
and short-term municipal bonds. Municipal notes are generally used to provide
for the issuer's short-term capital needs and generally have maturities of 397
days or less. Examples include tax anticipation and revenue anticipation notes,
which generally are issued in anticipation of various seasonal revenues, bond
anticipation notes, construction loan notes and tax-exempt commercial paper.
Short-term municipal bonds may include "general obligation bonds," which are
secured by the issuer's pledge of its faith, credit and taxing power for payment
of principal and interest; "revenue bonds," which are generally paid from the
revenues of a particular facility or a specific excise tax or other source; and
"industrial development bonds," which are issued by or on behalf of public
authorities to provide funding for various privately operated industrial and
commercial facilities. The Fund may also invest in high quality participation
interests in municipal securities. A more detailed description of various types
of municipal securities is contained in Appendix B in the Money Market Funds'
SAI.
 
When the assets and revenues of an agency, authority, instrumentality or other
political subdivision are separate from those of the government creating the
issuing entity and a security is backed only by the assets and revenues of the
issuing entity, that entity will be deemed to be the sole issuer of the
security. Similarly, in the case of an industrial development bond backed only
by the assets and revenues of the non-governmental issuer, the non-governmental
issuer will be deemed to be the sole issuer of the bond.
 
At times, the Fund may invest more than 25% of its total assets in tax-exempt
securities that are related in such a way that an economic, business, or
political development or change affecting one such security could similarly
affect the other securities; for example, securities whose issuers are located
in the same state, or securities whose interest is derived from revenues of
similar type projects. The Fund may also invest more than 25% of its assets in
industrial development bonds or participation interests therein.
 
Yields on municipal securities are dependent on a variety of factors, including
the general conditions of the money market and of the municipal bond and
municipal note markets, the size of a particular offering, the maturity of the
obligation and the rating of the issue. The achievement of the Fund's investment
objective is dependent in part on the continuing ability of the issuers of
municipal securities in which the Fund invests to meet their obligations for the
payment of principal and interest when due. Obligations of issuers of municipal
securities are subject to the provisions of bankruptcy, insolvency and other
laws affecting the rights and remedies of creditors, such as the Bankruptcy
Reform Act of 1978, as amended. Therefore, the possibility exists, that as a
result of litigation or other conditions, the ability of any issuer to pay, when
due, the principal of and interest on its municipal securities may be materially
affected.
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    27
    
<PAGE>   
 
MUNICIPAL LEASES
The Fund may invest in municipal leases or participation interests therein.
Municipal leases are municipal securities which may take the form of a lease or
an installment purchase or conditional sales contract. Municipal leases are
issued by state and local governments and authorities to acquire a wide variety
of equipment and facilities. Lease obligations may not be backed by the issuing
municipality's credit and may involve risks not normally associated with general
obligation bonds and other revenue bonds. For example, their interest may become
taxable if the lease is assigned and the holders may incur losses if the issuer
does not appropriate funds for the lease payment on an annual basis, which may
result in termination of the lease and possible default. Janus Capital may
determine that a liquid market exists for municipal lease obligations pursuant
to guidelines established by the Trustees.
 
TAXABLE INVESTMENTS
As discussed above, although the Fund will attempt to invest substantially all
of its assets in municipal securities whose interest is exempt from federal
income tax, the Fund may under certain circumstances invest in certain
securities whose interest is subject to such taxation. These securities include:
(i) short-term obligations of the U.S. government, its agencies or
instrumentalities, (ii) certificates of deposit, bankers' acceptances and
interest-bearing savings deposits of banks having total assets of more than one
billion dollars and whose deposits are insured by the Federal Deposit Insurance
Corporation, (iii) commercial paper and (iv) repurchase agreements as described
below covering any of the securities described in items (i)-(iii) above or any
other obligations of the U.S. government, its agencies or instrumentalities.
 
COMMON INVESTMENT TECHNIQUES
PARTICIPATION INTERESTS
The Money Market Funds may invest in participation interests in any type of
security in which the Money Market Funds may invest. A participation interest
gives a Money Market Fund an undivided interest in the underlying securities in
the proportion that the Money Market Fund's participation interest bears to the
total principal amount of the underlying securities. Participation interests
usually carry a demand feature, as described below, backed by a letter of credit
or guarantee of the institution that issued the interests permitting the holder
to tender them back to the institution.
 
DEMAND FEATURES
The Money Market Funds may invest in securities that are subject to puts and
stand-by commitments ("demand features"). Demand features give the Money Market
Funds the right to resell securities at specified periods prior to their
maturity dates to the seller or to some third party at an agreed-upon price or
yield. Securities with demand features may involve certain expenses and risks,
including the inability of the issuer of the instrument to pay for the
securities at the time the instrument is exercised, non-marketability of the
instrument and differences between the maturity of the underlying security and
the maturity of the instrument. Securities may cost more with demand features
than without them. Demand features can serve three purposes: to shorten the
maturity of a variable or floating rate security, to enhance the instrument's
credit quality and to provide a source of liquidity. Demand features are often
issued by third party financial institutions, generally domestic and foreign
banks. Accordingly, the credit
 
   
 28   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
quality and liquidity of the Money Market Funds' investments may be dependent in
part on the credit quality of the banks supporting the Money Market Funds'
investments. This will result in exposure to risks pertaining to the banking
industry, including the foreign banking industry. Brokerage firms and insurance
companies also provide certain liquidity and credit support. A substantial
portion of the Janus Tax-Exempt Money Market Fund's portfolio in particular may
consist of securities backed by banks and other financial institutions, and thus
adverse changes in the credit quality of these institutions could cause losses
to the Fund and affect its share price.
 
VARIABLE AND FLOATING RATE SECURITIES
The securities in which the Money Market Funds invest may have variable or
floating rates of interest. These securities pay interest at rates that are
adjusted periodically according to a specified formula, usually with reference
to some interest rate index or market interest rate. Securities with ultimate
maturities of greater than 397 days may be purchased only pursuant to Rule 2a-7.
Under that Rule, only those long-term instruments that have demand features
which comply with certain requirements and certain variable rate U.S. Government
Securities may be purchased. Similar to fixed rate debt instruments, variable
and floating rate instruments are subject to changes in value based on changes
in market interest rates or changes in the issuer's or guarantor's
creditworthiness. The rate of interest on securities purchased by a Money Market
Fund may be tied to short-term Treasury or other government securities or
indices on securities that are permissible investments of the Money Market
Funds, as well as other money market rates of interest. The Money Market Funds
will not purchase securities whose values are tied to interest rates or indices
that are not appropriate for the duration and volatility standards of a money
market fund.
 
MORTGAGE- AND ASSET-BACKED SECURITIES
Janus Money Market Fund and Janus Government Money Market Fund may purchase
fixed or adjustable rate mortgage-backed securities issued by the Government
National Mortgage Association, Federal National Mortgage Association, the
Federal Home Loan Mortgage Corporation, or other governmental or
government-related entities. In addition, Janus Money Market Fund may purchase
other asset-backed securities, including securities backed by automobile loans,
equipment leases or credit card receivables. These securities directly or
indirectly represent a participation in, or are secured by and payable from,
fixed or adjustable rate mortgage or other loans which may be secured by real
estate or other assets. Unlike traditional debt instruments, payments on these
securities include both interest and a partial payment of principal. Prepayments
of the principal of underlying loans may shorten the effective maturities of
these securities and may result in a Fund having to reinvest proceeds at a lower
interest rate.
 
REPURCHASE AGREEMENTS
Each Money Market Fund may seek additional income by entering into
collateralized repurchase agreements. Repurchase agreements are transactions in
which a Money Market Fund purchases securities and simultaneously commits to
resell those securities to the seller at an agreed-upon price on an agreed-upon
future date. The resale price reflects a market rate of interest that is not
related to the coupon rate or maturity of the purchased securities. If the
seller of the securities underlying a repurchase agreement fails to pay the
agreed resale price on the agreed delivery date, a Money Market Fund
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    29
    
<PAGE>   
 
may incur costs in disposing of the collateral and may experience losses if
there is any delay in its ability to do so.
 
REVERSE REPURCHASE AGREEMENTS
Each Money Market Fund may enter into reverse repurchase agreements. Reverse
repurchase agreements are transactions in which a Money Market Fund sells a
security and simultaneously commits to repurchase that security from the buyer
at an agreed-upon price on an agreed-upon future date. This technique will be
used primarily for temporary or emergency purposes, such as meeting redemption
requests.
 
DELAYED DELIVERY SECURITIES
Each Money Market Fund may purchase securities on a when-issued or delayed
delivery basis. Securities so purchased are subject to market price fluctuation
from the time of purchase but no interest on the securities accrues to a Money
Market Fund until delivery and payment for the securities take place.
Accordingly, the value of the securities on the delivery date may be more or
less than the purchase price. Forward commitments will be entered into only when
a Money Market Fund has the intention of taking possession of the securities,
but a Money Market Fund may sell the securities before the settlement date if
deemed advisable.
 
BORROWING AND LENDING
   
Each Money Market Fund may borrow money for temporary or emergency purposes in
amounts up to 25% of its total assets. A Money Market Fund may not mortgage or
pledge securities except to secure permitted borrowings. As a fundamental
policy, a Money Market Fund will not lend securities or other assets if, as a
result, more than 25% of its total assets would be lent to other parties. The
Money Market Funds do not currently intend to engage in securities lending;
however, under the terms of an exemptive order received from the SEC, each of
the Money Market Funds may borrow money from or lend money to other funds that
permit such transactions and are advised by Janus Capital.
    
 
   
 30   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
                              SHAREHOLDER'S MANUAL
 
This section will help you become familiar with the different types of accounts
you can establish with Janus. This section also explains in detail the wide
array of services and features you can establish on your account. These services
and features may be modified or discontinued without shareholder approval or
prior notice.
 
   
    MINIMUM INVESTMENTS*
    
 
   
<TABLE>
      <S>                                                  <C>
      To open a new account..............................   $2,500
      To open a new retirement, education, or UGMA/UTMA
        account..........................................   $  500
      To open a new account with an Automatic Investment
        Program..........................................   $  500**
      To add to any type of an account...................   $  100+
</TABLE>
    
 
   
     * THE FUNDS RESERVE THE RIGHT TO CHANGE THE AMOUNT OF THESE MINIMUMS
       FROM TIME TO TIME OR TO WAIVE THEM IN WHOLE OR IN PART FOR CERTAIN
       TYPES OF ACCOUNTS.
    
   
    ** AN AUTOMATIC INVESTMENT PROGRAM REQUIRES A $100 MINIMUM AUTOMATIC
       INVESTMENT PER MONTH UNTIL THE ACCOUNT BALANCE REACHES $2,500.
    
   
     + THE MINIMUM SUBSEQUENT INVESTMENT FOR IRA OR UGMA/UTMA ACCOUNTS IS
       $50.
    
 
HOW TO GET IN TOUCH WITH JANUS
   
If you have any questions while reading this Prospectus, please call one of our
Investor Service Representatives at 1-800-525-3713 Monday-Friday: 8:00 a.m.-8:00
p.m., and Saturday: 10:00 a.m.-4:00 p.m., New York time. The Quick Address and
Telephone Reference below includes other ways to get in touch with Janus.
    
 
   
   QUICK ADDRESS AND TELEPHONE REFERENCE
    
 
   
<TABLE>
    <S>                                     <C>
    MAILING ADDRESS                         JANUS XPRESS
    Janus                                   LINE(TM)     1-888-979-7737
    P.O. Box 173375                         For 24-hour access to account and
    Denver, CO 80217-3375                   fund information, exchanges and
                                            purchases, automated daily quotes
    FOR OVERNIGHT CARRIER                   on fund share prices, yields and
    Janus                                   total returns.
    Suite 101
    3773 Cherry Creek North Drive           TDD                  1-800-525-0056
    Denver, CO 80209-3811                   A telecommunications device for
                                            our hearing- and speech-impaired
    JANUS INTERNET ADDRESS                  shareholders.
    http://www.Janus.com
                                            JANUS LITERATURE
                                            LINE    1-800-525-8983
                                            To request a prospectus,
                                            shareholder reports or marketing
                                            materials.
</TABLE>
    
 
TYPES OF ACCOUNT OWNERSHIP
   
If you are investing in the Funds for the first time, you will need to establish
an account. You can establish the following types of accounts by completing a
New Account Application. To request an application, call 1-800-525-3713.
    
 
- - INDIVIDUAL OR JOINT OWNERSHIP. Individual accounts are owned by one person.
  Joint accounts have two or more owners.
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    31
    
<PAGE>   
 
- - A GIFT OR TRANSFER TO MINOR (UGMA OR UTMA). An UGMA/UTMA account is a
  custodial account managed for the benefit of a minor. To open an UGMA or UTMA
  account, you must include the minor's Social Security number on the
  application.
 
- - TRUST. An established trust can open an account. The names of each trustee,
  the name of the trust and the date of the trust agreement must be included on
  the application.
 
- - BUSINESS ACCOUNTS. Corporations and partnerships may also open an account. The
  application must be signed by an authorized officer of the corporation or a
  general partner of the partnership.
 
   
TAX-DEFERRED ACCOUNTS
    
   
If you are eligible, you may set up one or more tax-deferred accounts. A
tax-deferred account allows you to shelter your investment income and capital
gains from current income taxes. A contribution to certain of these plans may
also be tax deductible. Tax-deferred accounts include retirement plans and the
Education IRA. Distributions from these plans are generally subject to income
tax and may be subject to an additional tax if withdrawn prior to age 59 1/2 or
used for a nonqualifying purpose. Investors should consult their tax advisor or
legal counsel before selecting a tax-deferred account.
    
 
   
Investors Fiduciary Trust Company serves as custodian for the tax-deferred
accounts offered by the Funds. There is an annual $12 fee per account to
maintain your tax-deferred account. The maximum annual fee is $24 per taxpayer
identification number. You may pay the fee by check or have it automatically
deducted from your account (usually in December). The Funds reserve the right to
change the amount of this fee or to waive it in whole or in part for certain
types of accounts.
    
 
   
The following plans require a special application. For an application and more
details about our Retirement Plans, call 1-800-525-3713.
    
 
   
- - REGULAR AND ROTH INDIVIDUAL RETIREMENT ACCOUNTS ("IRAS"): Both types of IRAs
  allow most individuals with earned income to contribute up to the lesser of
  $2,000 ($4,000 for most married couples) or 100% of compensation annually.
  Please refer to the Janus IRA booklet for complete information regarding the
  different types of IRAs.
    
 
   
- - EDUCATION IRA: This plan allows individuals, subject to certain income
  limitations, to contribute up to $500 annually on behalf of any child under
  the age of 18. Please refer to the Janus IRA booklet for complete information
  regarding the Education IRA.
    
 
- - SIMPLIFIED EMPLOYEE PENSION PLAN ("SEP"): This plan allows small business
  owners (including sole proprietors) to make tax-deductible contributions for
  themselves and any eligible employee(s). A SEP requires an IRA (a SEP-IRA) to
  be set up for each SEP.
 
- - PROFIT SHARING OR MONEY PURCHASE PENSION PLAN: These plans are open to
  corporations, partnerships and sole proprietors to benefit their employees and
  themselves.
 
- - SECTION 403(B)(7) PLAN: Employees of educational organizations or other
  qualifying, tax-exempt organizations may be eligible to participate in a
  Section 403(b)(7) Plan.
 
   
 32   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
HOW TO OPEN YOUR JANUS ACCOUNT
   
Complete and sign the appropriate application. Please be sure to provide your
Social Security or taxpayer identification number on the application and make
your check payable to Janus. The Funds are available only to U.S. citizens or
residents, and your application will be returned if you do not meet these
criteria. Send all items to one of the following addresses:
    
 
   
For Overnight Carrier
    
- --------------------
Janus
Suite 101
3773 Cherry Creek North Drive
Denver, CO 80209-3811
 
   
For All Other Inquiries
    
- ---------------------
   
Janus
    
   
P.O. Box 173375
    
   
Denver, CO 80217-3375
    
 
INVESTOR SERVICE CENTERS
   
Janus offers two Investor Service Centers for those individuals who would like
to conduct their investing in person. Our representatives will be happy to
assist you at either of the following locations Monday-Friday 7:00 a.m. to 6:00
p.m. Mountain time and Saturday 9:00 a.m. to 1:00 p.m. Mountain time.
    
 
100 Fillmore Street, Suite 100
Denver, CO 80206
 
3773 Cherry Creek North Drive, Suite 101
Denver, CO 80209
 
HOW TO PURCHASE SHARES
 
PAYING FOR SHARES
When you purchase shares, your request will be processed at the next NAV
calculated after your order is received and accepted. Please note the following:
 
- - Cash, credit cards, third party checks and credit card checks will not be
  accepted.
 
- - All purchases must be made in U.S. dollars.
 
- - Checks must be drawn on U.S. banks and made payable to Janus.
 
- - If a check does not clear your bank, the Funds reserve the right to cancel the
  purchase.
 
- - If the Funds are unable to debit your predesignated bank account on the day of
  purchase, they may make additional attempts or cancel the purchase.
 
- - The Funds reserve the right to reject any specific purchase request.
 
If your purchase is cancelled, you will be responsible for any losses or fees
imposed by your bank and losses that may be incurred as a result of any decline
in the value of the
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    33
    
<PAGE>   
 
cancelled purchase. The Funds (or their agents) have the authority to redeem
shares in your account(s) to cover any losses due to fluctuations in share
price. Any profit on such cancellation will accrue to the Fund.
 
   
ONCE YOU HAVE OPENED YOUR JANUS ACCOUNT, THE MINIMUM AMOUNT FOR AN ADDITIONAL
INVESTMENT IS $100 ($50 FOR IRAS OR UGMA/UTMA ACCOUNTS). You may add to your
account at any time through any of the following options:
    
 
BY MAIL
Complete the remittance slip attached at the bottom of your confirmation
statement. If you are making a purchase into a retirement account, please
indicate whether the purchase is a rollover or a current or prior year
contribution. Send your check and remittance slip or written instructions to one
of the addresses listed previously. You may also request a booklet of remittance
slips for non-retirement accounts.
 
BY TELEPHONE
   
This service allows you to purchase additional shares quickly and conveniently
through an electronic transfer of money. To purchase shares by telephone, call
an Investor Service Representative at 1-800-525-3713 during normal business
hours or call the Janus Xpress Line, 1-888-979-7737, for access to this option
24 hours a day. When you make an additional purchase by telephone, Janus will
automatically debit your predesignated bank account for the desired amount. To
establish the telephone purchase option on your new account, complete the
"Telephone Purchase of Shares Option" section on the application and attach a
"voided" check or deposit slip from your bank account. If your account is
already established, call 1-800-525-3713 to request the appropriate form. This
option will become effective ten business days after the form is received.
    
 
BY WIRE
Purchases may also be made by wiring money from your bank account to your Janus
account. Call 1-800-525-3713 to receive wiring instructions.
 
AUTOMATIC INVESTMENT PROGRAMS
Janus offers several automatic investment programs to help you achieve your
financial goals as simply and conveniently as possible. You may open a new
account with a $500 initial purchase and $100 automatic subsequent investments.
 
- - AUTOMATIC MONTHLY INVESTMENT PROGRAM
  You select the day each month that your money ($100 minimum) will be
  electronically transferred from your bank account to your Fund account. To
  establish this option, complete the "Automatic Monthly Investment Program"
  section on the application and attach a "voided" check or deposit slip from
  your bank account. If your Fund account is already established, call
  1-800-525-3713 to request the appropriate form.
 
- - PAYROLL DEDUCTION
  If your employer can initiate an automatic payroll deduction, you may have all
  or a portion of your paycheck ($100 minimum) invested directly into your Fund
  account. To obtain information on establishing this option, call
  1-800-525-3713.
 
- - SYSTEMATIC EXCHANGE
  With a Systematic Exchange you determine the amount of money ($100 minimum)
  you would like automatically exchanged from one Janus account to another on
  any day
 
   
 34   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
  of the month. For more information on how to establish this option, call
  1-800-525-3713.
 
HOW TO EXCHANGE SHARES
On any business day, you may exchange all or a portion of your shares into any
other available Janus fund.
 
IN WRITING
   
To request an exchange in writing, please follow the instructions for written
requests on page 37.
    
 
BY TELEPHONE
   
All accounts are automatically eligible for the telephone exchange option. To
exchange shares by telephone, call an Investor Service Representative at
1-800-525-3713 during normal business hours or call the Janus Xpress Line,
1-888-979-7737, for access to this option 24 hours a day.
    
 
BY SYSTEMATIC EXCHANGE
   
As noted above, you may establish a Systematic Exchange for as little as $100
per month on established accounts. You may establish a new account with a $500
initial purchase and subsequent $100 systematic exchanges. If the balance in the
account you are exchanging from falls below the systematic exchange amount, all
remaining shares will be exchanged and the program will be discontinued.
    
 
EXCHANGE POLICIES
- - Except for Systematic Exchanges, new accounts established by exchange must be
  opened with $2,500 or the total account value if the value of the account you
  are exchanging from is less than $2,500.
 
- - Exchanges between existing accounts must meet the $100 subsequent investment
  requirement.
 
- - You may make four exchanges out of each non-Money Market Fund during a
  calendar year (exclusive of Systematic Exchanges) free of charge. There is
  currently no limit on exchanges out of the Money Market Funds.
 
- - Exchanges between accounts will be accepted only if the registrations are
  identical.
 
- - If the shares you are exchanging are held in certificate form, you must return
  the certificate to your Fund prior to making any exchanges.
 
- - Be sure that you read the prospectus for the fund into which you are
  exchanging.
 
- - The Funds reserve the right to reject any exchange request and to modify or
  terminate the exchange privilege at any time. For example, the Funds may
  reject exchanges from accounts engaged in excessive trading (including market
  timing transactions) that are believed to be detrimental to the Funds.
 
- - An exchange represents the sale of shares from one fund and the purchase of
  shares of another fund, which may produce a taxable gain or loss in a non-tax
  deferred account. Because the Money Market Funds seek to maintain a stable net
  asset value per share,
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    35
    
<PAGE>   
 
  it is not anticipated that a sale of Shares of the Money Market Funds will
  produce a taxable gain or loss.
 
   
HOW TO REDEEM SHARES
    
On any business day, you may redeem all or a portion of your shares. If the
shares are held in certificate form, the certificate must be returned with or
before your redemption request. Your transaction will be processed at the next
NAV calculated after your order is received and accepted.
 
IN WRITING
   
To request a redemption in writing, please follow the instructions for written
requests on page 37.
    
 
BY TELEPHONE
   
Most accounts have the telephone redemption option, unless this option was
specifically declined on the application or in writing. This option enables you
to request redemptions daily from your account by calling 1-800-525-3713 by the
close of the regular trading session of the New York Stock Exchange ("NYSE")
normally 4:00 p.m. New York time. You may also use Janus Xpress Line,
1-888-979-7737, for access to this option 24 hours a day. Redemption requests
received through Janus Xpress Line will be processed at the NAV next calculated
after receipt and acceptance of the request. (There is a daily limit of $100,000
per account for redemptions payable by check.)
    
 
SYSTEMATIC REDEMPTION OPTION
Systematic Redemption Options allow you to redeem a specific dollar amount from
your account on a regular basis. For more information or to request the
appropriate form, please call 1-800-525-3713.
 
PAYMENT OF REDEMPTION PROCEEDS
- - BY CHECK
  Redemption proceeds will be sent to the shareholder(s) of record at the
  address of record within seven days after receipt of a valid redemption
  request.
 
   
- - BY ELECTRONIC TRANSFER
    
   
  If you have established the electronic redemption option, your redemption
  proceeds can be electronically transferred to your predesignated bank account
  on the next bank business day after receipt of your redemption request (wire
  transfer) or the second bank business day after receipt of your redemption
  request (ACH transfer). Wire transfers will be charged an $8 fee per wire and
  your bank may charge an additional fee to receive the wire. ACH transfers are
  made free of charge. Wire redemptions are not available for retirement
  accounts.
    
 
   
  If you would like to establish the electronic redemption option on an existing
  account, please call 1-800-525-3713 to request the appropriate form.
    
 
IF THE SHARES BEING REDEEMED WERE PURCHASED BY CHECK, TELEPHONE OR THROUGH THE
AUTOMATIC MONTHLY INVESTMENT PROGRAM, THE FIXED-INCOME FUNDS MAY DELAY THE
PAYMENT OF YOUR REDEMPTION PROCEEDS FOR UP TO 15 DAYS FROM THE DAY OF PURCHASE
TO ALLOW THE PURCHASE TO CLEAR. Unless you
 
   
 36   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
provide alternate instructions, your proceeds will be invested in Janus Money
Market Fund - Investor Shares during the 15 day hold period.
 
   
WRITTEN INSTRUCTIONS
    
   
To redeem or exchange all or part of your shares in writing, your request should
be sent to one of the addresses listed on page 33 and must include the following
information:
    
 
- - the name of the Fund(s)
 
- - the account number(s)
 
- - the amount of money or number of shares being redeemed
 
- - the name(s) on the account
 
- - the signature(s) of all registered account owners
 
- - your daytime telephone number
 
SIGNATURE REQUIREMENTS BASED ON ACCOUNT TYPE
 
- - Individual, Joint Tenants, Tenants in Common: Written instructions must
 --------------------------------------------
  be signed by each shareholder, exactly as the names appear in the account
  registration.
 
- - UGMA or UTMA: Written instructions must be signed by the custodian in
 ------------------
  his/her capacity as it appears in the account registration.
 
- - Sole Proprietor, General Partner: Written instructions must be signed
 --------------------------------
  by an authorized individual in his/her capacity as it appears in the account
  registration.
 
- - Corporation, Association: Written instructions must be signed by the
 ------------------------
  person(s) authorized to act on the account. In addition, a certified copy of 
  the corporate resolution authorizing the signer to act must accompany the 
  request.
  
- - Trust: Written instructions must be signed by the trustee(s). If the name of
 ------
  the current trustee(s) does not appear in the account registration, a
  certificate of incumbency dated within 60 days must also be submitted.
 
- - IRA: Written instructions must be signed by the account owner. If you do
 -----
   
  not want federal income tax withheld from your redemption, you must state that
  you elect not to have such withholding apply. In addition, your instructions
  must state whether the distribution is normal (after age 59 1/2) or premature
  (before age 59 1/2) and, if premature, whether any exceptions such as death or
  disability apply with regard to the 10% additional tax on early distributions.
    
 
   
SIGNATURE GUARANTEE
    
In addition to the signature requirements, A SIGNATURE GUARANTEE IS ALSO
REQUIRED if any of the following is applicable:
 
   
- - You request a redemption that exceeds $100,000.
    
 
- - You would like the check made payable to anyone other than the shareholder(s)
  of record.
 
- - You would like the check mailed to an address which has been changed within 10
  days of the redemption request.
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    37
    
<PAGE>   
 
- - You would like the check mailed to an address other than the address of
  record.
 
THE FUNDS RESERVE THE RIGHT TO REQUIRE A SIGNATURE GUARANTEE UNDER OTHER
CIRCUMSTANCES OR TO REJECT OR DELAY A REDEMPTION ON CERTAIN LEGAL GROUNDS. FOR
MORE INFORMATION PERTAINING TO SIGNATURE GUARANTEES, PLEASE CALL 1-800-525-3713.
 
HOW TO OBTAIN A SIGNATURE GUARANTEE
A signature guarantee assures that a signature is genuine. The signature
guarantee protects shareholders from unauthorized account transfers. The
following financial institutions may guarantee signatures: banks, savings and
loan associations, trust companies, credit unions, broker-dealers, and member
firms of a national securities exchange. Call your financial institution to see
if they have the ability to guarantee a signature. A signature guarantee may not
be provided by a notary public.
 
If you live outside the United States, a foreign bank properly authorized to do
business in your country of residence or a U.S. consulate may be able to
authenticate your signature.
 
   
PRICING OF FUND SHARES
    
   
All purchases, redemptions and exchanges will be processed at the NAV next
calculated after your request is received and approved by a Fund (or its
designated agent). A Fund's NAV is calculated at the close of the regular
trading session of the NYSE (normally 4:00 p.m. New York time) each day that the
NYSE is open. In order to receive a day's price, your order must be received by
the close of the regular trading session of the NYSE. The Money Market Funds
reserve the right to require purchase, redemption and exchange requests and
payments prior to this time on days when the bond market closes before the NYSE.
    
 
   
For the Fixed-Income Funds, securities are valued at market value or, if a
market quotation is not readily available, at their fair value determined in
good faith under procedures established by and under the supervision of the
Trustees. Short-term instruments maturing within 60 days are valued at amortized
cost, which approximates market value.
    
 
   
For the Money Market Funds, portfolio securities are valued at their amortized
cost. Amortized cost valuation involves valuing an instrument at its cost and
thereafter assuming a constant amortization to maturity (or such other date as
permitted by Rule 2a-7) of any discount or premium. If fluctuating interest
rates cause the market value of a Fund's portfolio to deviate more than 1/2 of
1% from the value determined on the basis of amortized cost, the Trustees will
consider whether any action, such as adjusting the Share's NAV to reflect
current market conditions, should be initiated to prevent any material dilutive
effect on shareholders.
    
 
   
See your Fund's SAI for more detailed information.
    
 
SHAREHOLDER SERVICES AND ACCOUNT POLICIES
   
JANUS XPRESS LINE(TM)
    
   
Janus Xpress Line, our electronic telephone service, offers you 24-hour access
by TouchTone(TM) telephone to obtain information on account balances, Fund
performance or
    
 
   
 38   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
   
dividends. You can also make exchanges, purchases, redemptions and electronic
transfers in existing accounts, request literature about any Janus fund, or
order duplicate statements. Janus Xpress Line is accessed by calling
1-888-979-7737. Calls are limited to five minutes.
    
 
JANUS WEB SITE
   
Janus maintains a Web site located at http://www.Janus.com. You can access
information such as your account balance and the Funds' NAVs through the Web
site. In addition, you may request and/or download a prospectus for any Janus
fund.
    
 
CHECK WRITING PRIVILEGE
Check writing privileges are available for all three Money Market Funds.
Checkbooks will be issued to shareholders who have completed a Signature Draft
Card, which is sent in the new account welcome package or by calling
1-800-525-3713. (There is no checkwriting privilege for retirement accounts.)
Your checkbook will be mailed approximately 10 days after the check writing
privilege is requested. Checks may be written for $250 or more per check.
Purchases made by check or the Automatic Monthly Investment Program may not be
redeemed by a redemption check until the 15-day hold period has passed. All
checks written on the account must be signed by all account holders unless
otherwise specified on the original application or the subsequent Signature
Draft Card. The Funds reserve the right to terminate or modify the check writing
privilege at any time.
 
ACCOUNT MINIMUMS
   
Minimum account sizes are noted on page 31. An account established on or before
February 18, 1996 is required to meet the minimum balances in effect when the
account was established ($1,000 for regular accounts and $250 for retirement and
UGMA/UTMA accounts). An active Automatic Monthly Investment (AMI) on any such
account exempted it from any minimum initial investment requirement and
continues to do so. In addition, an active AMI on these accounts may continue at
$50 per month, provided there is no interruption in the AMI program. All other
subsequent investments must meet the $100 required minimum.
    
 
   
Due to the proportionately higher costs of maintaining small accounts, Janus
reserves the right to deduct a $10 minimum balance fee (or the value of the
account if less than $10) from accounts with values below the minimums described
on page 31 or to close such accounts. This policy will apply to accounts
participating in the Automatic Monthly Investment Program only if your account
balance does not reach the required minimum initial investment or falls below
such minimum and you have discontinued monthly investments. This policy does not
apply to accounts that fall below the minimums solely as a result of market
value fluctuations. It is expected that, for purposes of this policy, accounts
will be valued in September, and the $10 fee will be assessed on the second
Friday of September of each year. You will receive notice before we charge the
$10 fee or close your account so that you may increase your account balance to
the required minimum.
    
 
TRANSACTIONS THROUGH PROCESSING ORGANIZATIONS
You may purchase or sell Fund shares through a broker-dealer, bank or other
financial institution, or an organization that provides recordkeeping and
consulting services to
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    39
    
<PAGE>   
 
401(k) plans or other employee benefit plans (a "Processing Organization").
Processing Organizations may charge you a fee for this service and may require
different minimum initial and subsequent investments than the Funds. Processing
Organizations may also impose other charges or restrictions different from those
applicable to shareholders who invest in the Funds directly. A Processing
Organization, rather than its customers, may be the shareholder of record of
your shares. The Funds are not responsible for the failure of any Processing
Organization to carry out its obligations to its customers. Certain Processing
Organizations may receive compensation from Janus Capital or its affiliates and
certain Processing Organizations may receive compensation from the Funds for
shareholder recordkeeping and similar services.
 
TAXPAYER IDENTIFICATION NUMBER
On the application or other appropriate form, you will be asked to certify that
your Social Security or taxpayer identification number is correct and that you
are not subject to backup withholding for failing to report income to the IRS.
If you are subject to the 31% backup withholding or you did not certify your
taxpayer identification, the IRS requires the Funds to withhold 31% of any
dividends paid and redemption or exchange proceeds. In addition to the 31%
backup withholding, you may be subject to a $50 fee to reimburse the Funds for
any penalty that the IRS may impose.
 
SHARE CERTIFICATES
(FIXED-INCOME FUNDS ONLY)
Most shareholders choose not to hold their shares in certificate form because
account transactions such as exchanges and redemptions cannot be completed until
the certificate has been returned to the Funds. The Fixed-Income Funds will
issue share certificates upon written request only. Share certificates will not
be issued until the shares have been held for at least 15 days and will not be
issued for accounts that do not meet the minimum investment requirements. Share
certificates cannot be issued for retirement accounts. In addition, if the
certificate is lost, there may be a replacement charge.
 
Share certificates are not available for the Money Market Funds in order to
maintain the general liquidity that is representative of a money market fund and
to help facilitate transactions in shareholder accounts.
 
INVOLUNTARY REDEMPTIONS
The Funds reserve the right to close an account if the shareholder is deemed to
engage in activities which are illegal or otherwise believed to be detrimental
to the Funds.
 
TELEPHONE TRANSACTIONS
You may initiate many transactions by telephone. The Funds and their agents will
not be responsible for any losses resulting from unauthorized transactions when
procedures designed to verify the identity of the caller are followed.
 
   
It may be difficult to reach an Investor Service Representative by telephone
during periods of unusual market activity. If you are unable to reach a
representative by telephone, please consider sending written instructions,
stopping by a Service Center or, in the case of purchases, exchanges,
redemptions and electronic transfers, calling the Janus Xpress Line.
    
 
   
 40   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
TEMPORARY SUSPENSION OF SERVICES
The Funds or their agents may, in case of emergency, temporarily suspend
telephone transactions and other shareholder services.
 
ADDRESS CHANGES
To change the address on your account, call 1-800-525-3713 or send a written
request signed by all account owners. Include the name of your Fund(s), the
account number(s), the name(s) on the account and both the old and new
addresses. Certain options may be suspended for 10 days following an address
change unless a signature guarantee is provided.
 
REGISTRATION CHANGES
To change the name on an account, the shares are generally transferred to a new
account. In some cases, legal documentation may be required. For more
information, call 1-800-525-3713.
 
STATEMENTS AND REPORTS
   
Investors participating in an automatic investment program will receive
quarterly confirmations of all transactions. Dividend information will be
confirmed quarterly. In addition, the Funds will send you an immediate
transaction confirmation statement after every non-systematic transaction.
    
 
Financial reports for the Funds, which include a list of the Funds' portfolio
holdings, will be mailed semiannually to all shareholders. To reduce expenses,
only one copy of most financial reports will be mailed to accounts with the same
record address. Upon request, such reports will be mailed to all accounts in the
same household. Please call 1-800-525-3713 if you would like to receive
additional reports.
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    41
    
<PAGE>   
 
                            MANAGEMENT OF THE FUNDS
 
TRUSTEES
The Trustees oversee the business affairs of the Trust and are responsible for
major decisions relating to each Fund's investment objectives and policies. The
Trustees delegate the day-to-day management of the Funds to the officers of the
Trust and meet at least quarterly to review the Funds' investment policies,
performance, expenses and other business affairs.
 
INVESTMENT ADVISER
Janus Capital, 100 Fillmore Street, Denver, Colorado 80206-4928, is the
investment adviser to each of the Funds and is responsible for the day-to-day
management of the investment portfolios and other business affairs of the Funds.
 
Janus Capital began serving as investment adviser to certain series of the Trust
in 1970 and currently serves as investment adviser to all of the Janus funds, as
well as adviser or subadviser to other mutual funds and individual, corporate,
charitable and retirement accounts.
 
Kansas City Southern Industries, Inc. ("KCSI") owns approximately 83% of the
outstanding voting stock of Janus Capital, most of which it acquired in 1984.
KCSI is a publicly traded holding company whose primary subsidiaries are engaged
in transportation, information processing and financial services. Thomas H.
Bailey, President and Chairman of the Board of Janus Capital, owns approximately
12% of its voting stock and, by agreement with KCSI, selects a majority of Janus
Capital's Board.
 
Janus Capital furnishes continuous advice and recommendations concerning each
Fund's investments. Janus Capital also furnishes certain administrative,
compliance and accounting services for the Funds, and may be reimbursed by the
Fixed-Income Funds for its costs in providing those services. In addition, Janus
Capital employees serve as officers of the Trust and Janus Capital provides
office space for the Funds and pays the salaries, fees and expenses of all Fund
officers and those Trustees who are affiliated with Janus Capital. The Funds pay
all of their expenses not assumed by Janus Capital, including auditing fees and
independent Trustees' fees and expenses. (Janus Capital provides these services
to the Money Market Funds pursuant to an Administration Agreement as described
below.)
 
ADMINISTRATOR
Each of the Money Market Funds has entered into an Administration Agreement with
Janus Capital, pursuant to which Janus Capital furnishes certain administrative,
compliance and accounting services for the Money Market Funds, pays the costs of
printing reports and prospectuses for existing shareholders, provides office
space for the Money Market Funds and pays the salaries, fees and expenses of
Fund officers and of those Trustees who are affiliated with Janus Capital.
Administrative services provided by Janus Capital under the Agreements include
custody and transfer agency services.
 
   
 42   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
INVESTMENT PERSONNEL
SHARON S. PICHLER is Executive Vice President and portfolio manager of Janus
Money Market Fund, Janus Government Money Market Fund and Janus Tax-Exempt Money
Market Fund, each of which she has managed since inception. She holds a Bachelor
of Arts in Economics from Michigan State University and a Master of Business
Administration from the University of Texas at San Antonio. Ms. Pichler is a
Chartered Financial Analyst.
 
SANDY R. RUFENACHT is Executive Vice President and portfolio manager of Janus
Short-Term Bond Fund, which he has managed since January 1996. Since June 1996,
he has served as Executive Vice President and co-manager of Janus High-Yield
Fund and Janus Flexible Income Fund. Mr. Rufenacht joined Janus Capital in 1990
and gained experience as a trader and research analyst before assuming
management of these funds. He holds a Bachelor of Arts in Business from the
University of Northern Colorado.
 
   
RONALD V. SPEAKER is Executive Vice President and co-manager of Janus Flexible
Income Fund, which he has managed since December 1991 and Janus High-Yield Fund,
which he has managed since inception. He previously managed Janus Short-Term
Bond Fund and Janus Federal Tax-Exempt Fund from their inceptions through
December 1995. He holds a Bachelor of Arts in Finance from the University of
Colorado and is a Chartered Financial Analyst.
    
 
   
In January 1997, Mr. Speaker settled an SEC administrative action involving two
personal trades made by him in January of 1993. Without admitting or denying the
allegations, Mr. Speaker agreed to civil money penalty, disgorgement, and
interest payments totaling $37,199 and to a 90-day suspension which ended on
April 25, 1997.
    
 
   
DARRELL W. WATTERS is Executive Vice President and portfolio manager of Janus
Federal Tax-Exempt Fund, which he has managed since January 1996. Mr. Watters
joined Janus Capital in 1993 as a municipal bond trader. He holds a Bachelor of
Arts in Economics from Colorado State University.
    
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    43
    
<PAGE>   
 
   
PERSONAL INVESTING
    
   
Janus Capital does not permit portfolio managers to purchase and sell securities
for their own accounts, except under the limited exceptions contained in Janus
Capital's policy governing personal investing. Janus Capital's policy requires
investment and other personnel to conduct their personal investment activities
in a manner that Janus Capital believes is not detrimental to the Funds or Janus
Capital's other advisory clients. See the SAI for more detailed information.
    
 
BREAKDOWN OF MANAGEMENT EXPENSES AND EXPENSE LIMITS
FIXED-INCOME FUNDS
Each Fund pays Janus Capital a management fee which is calculated daily and paid
monthly. The advisory agreement with each Fund spells out the management fee and
other expenses that the Funds must pay. Each of the Funds is subject to the
following management fee schedule (expressed as an annual rate):
 
<TABLE>
<CAPTION>
                                AVERAGE DAILY NET       ANNUAL RATE        EXPENSE LIMIT
         FEE SCHEDULE            ASSETS OF FUND        PERCENTAGE (%)      PERCENTAGE (%)
    <S>                         <C>                    <C>                 <C>
</TABLE>
 
- --------------------------------------------------------------------------------
 
   
<TABLE>
    <S>                         <C>                    <C>                 <C>
    Janus Flexible Income       First $300             0.65                1.00*
      Fund                      Million
                                Over $300 Million      0.55
    ------------------------------------------------------------------------------
                                First $300             0.75                1.00*
    Janus High-Yield Fund       Million
                                Over $300 Million      0.65
    ------------------------------------------------------------------------------
    Janus Federal               First $300             0.60                .65*
      Tax-Exempt                Million
      Fund                      Over $300 Million      0.55
    ------------------------------------------------------------------------------
                                First $300             0.65                .65*
    Janus Short-Term Bond       Million
      Fund                      Over $300 Million      0.55
</TABLE>
    
 
 * Janus Capital will waive certain fees and expenses to the extent that total
   expenses exceed the stated limits. Janus Capital may modify or terminate such
   waivers at any time upon at least 90 days' notice to
   the Trustees. You will be notified of any changes in these limits.
- --------------------------------------------------------------------------------
 
   
Each Fixed-Income Fund incurs expenses not assumed by Janus Capital, including
transfer agent and custodian fees and expenses, legal and auditing fees,
printing and mailing costs of sending reports and other information to existing
shareholders, and independent Trustees' fees and expenses. The Annual Operating
Expenses table on page 6 lists the actual management fees and total operating
expenses of each Fund for the most recent fiscal year.
    
 
MONEY MARKET FUNDS
Each of the Money Market Funds has agreed to compensate Janus Capital for its
advisory services by the monthly payment of a fee at the annual rate of 0.20% of
the value of the average daily net assets of each Money Market Fund. However,
Janus Capital has agreed to waive a portion of its fee and accordingly, the
advisory fee of each Money Market Fund will be calculated at the annual rate of
0.10% of the value of each Money Market Fund's average daily net assets. Janus
Capital may modify or terminate such waiver at any time upon at least 90 days'
notice to the Trustees. You will be notified of any change in this limit.
 
Janus Capital is paid a fee, calculated daily and paid monthly, at the annual
rate of 0.50% of the value of the average daily net assets of each Money Market
Fund attributable to Shares for services rendered pursuant to the Administration
Agreements.
   
 44   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
   
PORTFOLIO TRANSACTIONS
    
   
Purchases and sales of securities on behalf of each Fund are executed by
broker-dealers selected by Janus Capital. Broker-dealers are selected on the
basis of their ability to obtain best price and execution for a Fund's
transactions and recognizing brokerage, research and other services provided to
the Fund and to Janus Capital. Janus Capital may also consider payments made by
brokers effecting transactions for a Fund i) to the Fund or ii) to other persons
on behalf of the Fund for services provided to the Fund for which it would be
obligated to pay. Janus Capital may also consider sales of shares of a Janus
fund as a factor in the selection of broker-dealers to execute transactions. The
Funds' Trustees have authorized Janus Capital to place portfolio transactions on
an agency basis with a broker-dealer affiliated with Janus Capital. When
transactions for a Fund are effected with that broker-dealer, the commissions
payable by the Fund are credited against certain Fund operating expenses serving
to reduce those expenses. The SAI further explains the selection of
broker-dealers.
    
 
OTHER SERVICE PROVIDERS
The following parties provide the Funds with other services.
 
CUSTODIAN FOR THE FIXED-INCOME FUNDS
State Street Bank and Trust Company
P.O. Box 0351
Boston, Massachusetts 02117-0351
 
CUSTODIAN FOR THE MONEY MARKET FUNDS
   
UMB Bank, N.A.
    
P.O. Box 419226
Kansas City, Missouri 64141-6226
 
TRANSFER AGENT
Janus Service Corporation
P.O. Box 173375
Denver, Colorado 80217-3375
 
DISTRIBUTOR
Janus Distributors, Inc.
100 Fillmore Street
Denver, Colorado 80206-4928
 
Janus Service Corporation and Janus Distributors, Inc. are wholly-owned
subsidiaries of Janus Capital.
 
OTHER INFORMATION
ORGANIZATION
The Trust is a "mutual fund" that was organized as a Massachusetts business
trust on February 11, 1986. A mutual fund is an investment vehicle that pools
money from numerous investors and invests the money to achieve a specified
objective.
 
   
As of the date of this Prospectus, the Trust offers 19 separate series. Each of
the Money Market Funds currently offer three classes of shares. This prospectus
only describes the
    
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    45
    
<PAGE>   
 
Investor Shares of the Money Market Funds. Institutional Shares of the Money
Market Funds are available only to investors meeting the minimum investment
requirement of $250,000. Service Shares of the Money Market Funds are available
only to banks and other financial institutions that meet minimum investment
requirements in connection with trust accounts, cash management programs and
similar programs. Because the expenses of each class may differ, the performance
of each class is expected to differ. If you would like additional information,
please call 1-800-525-3713. This Prospectus describes seven series of the Trust;
the other series are offered by separate prospectuses.
 
SHAREHOLDER MEETINGS
The Trust does not intend to hold annual shareholder meetings. However, special
meetings may be called for a specific Fund or for the Trust as a whole for
purposes such as electing or removing Trustees, terminating or reorganizing the
Trust, changing fundamental policies, or for any other purpose requiring a
shareholder vote under the 1940 Act. Separate votes are taken by each Fund only
if a matter affects or requires the vote of only that Fund or that Fund's
interest in the matter differs from the interest of other portfolios of the
Trust. As a shareholder, you are entitled to one vote for each share that you
own.
 
SIZE OF FUNDS
The Funds have no present plans to limit their size. However, any Fund may
discontinue sales of its shares if management believes that continued sales may
adversely affect the Fund's ability to achieve its investment objective. If
sales of a Fund are discontinued, it is expected that existing shareholders of
that Fund would be permitted to continue to purchase shares and to reinvest any
dividends or capital gains distributions, absent highly unusual circumstances.
 
MASTER/FEEDER OPTION
   
The Trust may in the future seek to achieve any Fund's investment objective by
investing all of that Fund's assets in another investment company having the
same investment objective and substantially the same investment policies and
restrictions as those applicable to that Fund. Unless otherwise required by law,
this policy may be implemented by the Trustees without shareholder approval.
    
 
   
YEAR 2000
    
   
Many computer systems use six-digit fields to store dates. With the approach of
the year 2000, these fields must be converted to eight-digit fields in order to
recognize the difference between 1900 and 2000. Failure to adequately address
this issue could have potentially serious repercussions. Preparing for Year 2000
is a high priority for Janus Capital, which has established a dedicated group to
address this issue and has entered into a consulting arrangement with one of the
foremost experts in Year 2000 compliance to assess systems implications for
Janus Capital. Janus Capital does not anticipate that the move to Year 2000 will
have a material impact on its ability to continue to provide Funds with service
at current levels.
    
 
   
 46   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
                            DISTRIBUTIONS AND TAXES
 
DISTRIBUTIONS
   
TO AVOID TAXATION, THE INTERNAL REVENUE CODE REQUIRES EACH FUND TO DISTRIBUTE
NET INCOME AND ANY NET CAPITAL GAINS REALIZED BY ITS INVESTMENTS ANNUALLY. A
FUND'S INCOME FROM DIVIDENDS AND INTEREST AND ANY NET REALIZED SHORT-TERM
CAPITAL GAINS ARE PAID TO SHAREHOLDERS AS ORDINARY INCOME DIVIDENDS. NET
REALIZED LONG-TERM GAINS, IF ANY, ARE PAID TO SHAREHOLDERS AS CAPITAL GAINS
DISTRIBUTIONS.
    
 
THE FIXED-INCOME FUNDS
Income dividends for the Fixed-Income Funds are declared daily, Saturdays,
Sundays and holidays included, and are generally paid as of the last business
day of each month. If a month begins on a Saturday, Sunday or holiday, dividends
for those days are paid at the end of the preceding month. An investor will
begin accruing income dividends the day after a purchase is effective. If shares
are redeemed, the investor will receive all dividends accrued through the day of
the redemption. Capital gains, if any, are declared and paid in December.
 
HOW DISTRIBUTIONS AFFECT A FUND'S NAV
Distributions are paid to shareholders as of the record date of a distribution
of a Fund, regardless of how long the shares have been held. Dividends and
capital gains awaiting distribution are included in each Fund's daily NAV. The
share price of a Fund drops by the amount of the distribution, net of any
subsequent market fluctuations. As an example, assume that on December 31, Janus
Flexible Income Fund declared a dividend in the amount of $0.25 per share. If
Janus Flexible Income Fund's share price was $10.00 on December 30, the Fund's
share price on December 31 would be $9.75, barring market fluctuations.
Shareholders should be aware that distributions from a taxable mutual fund are
not value-enhancing and may create income tax obligations. Capital gains
distributions, if any, for Janus Federal Tax-Exempt Fund will also be taxable.
 
"BUYING A DIVIDEND"
If you purchase shares of a Fund just before the distribution, you will pay the
full price for the shares and receive a portion of the purchase price back as a
taxable distribution. This is referred to as "buying a dividend." In the above
example, if you bought shares on December 30, you would have paid $10.00 per
share. On December 31, the Fund would pay you $0.25 per share as a dividend and
your shares would now be worth $9.75 per share. Unless your account is set up as
a tax-deferred account, dividends paid to you would be included in your gross
income for tax purposes even though you may not have participated in the
increase in NAV of the Fund, whether or not you reinvested the dividends.
 
THE MONEY MARKET FUNDS
For the Money Market Funds, dividends representing substantially all of the net
investment income and any net realized gains on sales of securities are declared
daily,
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    47
    
<PAGE>   
 
Saturdays, Sundays and holidays included, and distributed on the last business
day of each month. If a month begins on a Saturday, Sunday or holiday, dividends
for those days are declared at the end of the preceding month and distributed on
the first business day of the month.
 
Shares of the Money Market Funds purchased by wire on a day on which the Funds
calculate their net asset value and the Federal Reserve Banks are open ("bank
business day") will receive that day's dividend if the purchase is effected
prior to 3:00 p.m. (New York time) for the Janus Money Market and Janus
Government Money Market Funds and 12:00 p.m. (New York time) for Janus
Tax-Exempt Money Market Fund. Otherwise, such Shares begin to accrue dividends
on the following bank business day. Orders for purchase accompanied by a check
or other negotiable bank draft will be accepted and effected as of 4:00 p.m.
(New York time) on the business day of receipt and such Shares will begin to
accrue dividends on the first bank business day following receipt of the order.
 
Redemption orders effected on any particular day will generally receive
dividends declared through the day of redemption. However, redemptions made by
wire which are received prior to 3:00 p.m. (New York time) for the Janus Money
Market and Janus Government Money Market Funds and 12:00 p.m. (New York time)
for Janus Tax-Exempt Money Market Fund will result in Shares being redeemed that
day. Proceeds of such a redemption will normally be sent to the predesignated
account on that day, and that day's dividend will not be received. Requests for
redemptions made by wire which are received after 3:00 p.m. (12:00 p.m. for
Janus Tax-Exempt Money Market Fund) will be processed on that day and receive
that day's dividend, but will not be wired until the following bank business
day.
 
The Funds reserve the right to require purchase and redemption requests and
payments prior to these times on days when the bond market closes before 4:00
p.m.
 
DISTRIBUTION OPTIONS
   
When you open an account, you must specify on your application how you want to
receive your distributions. You may change your distribution option at any time
by writing the Funds at one of the addresses on page 33 or calling
1-800-525-3713. The Funds offer the following options:
    
 
1. REINVESTMENT OPTION. You may reinvest your income dividends and capital gains
   distributions in additional shares. This option is assigned automatically if
   no other choice is made.
 
2. CASH OPTION. You may receive your income dividends and capital gains
   distributions in cash.
 
3. REINVEST AND CASH OPTION (THE FIXED-INCOME FUNDS ONLY). You may receive
   either your income dividends or capital gains distributions in cash and
   reinvest the other in additional shares.
 
4. REDIRECT OPTION. You may direct your dividends or capital gains distributions
   (dividends in the case of the Money Market Funds) to purchase shares of
   another Janus fund.
 
   
 48   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
The Funds reserve the right to reinvest into your account undeliverable and
uncashed dividend and distribution checks that remain outstanding for six months
in shares of the applicable Fund at the NAV next computed after the check is
cancelled. Subsequent distributions may also be reinvested.
 
TAXES
   
As with any investment, you should consider the tax consequences of investing in
the Funds. The following discussion does not apply to tax-deferred accounts, nor
is it a complete analysis of the federal tax implications of investing in the
Funds. You may wish to consult your own tax adviser. Additionally, state or
local taxes may apply to your investment, depending upon the laws of your state
of residence.
    
 
TAXES ON DISTRIBUTIONS
Janus Federal Tax-Exempt Fund and Janus Tax-Exempt Money Market Fund anticipate
that substantially all their income dividends will be exempt from federal income
tax, although either Fund may occasionally earn income on taxable investments
and dividends attributable to that income would be taxable. In addition,
interest from certain private activity bonds is a preference item for purposes
of the alternative minimum tax, and to the extent a Fund earns such income,
shareholders subject to the alternative minimum tax must include that income as
a preference item. Distributions from capital gains, if any, are subject to
federal tax. The Funds will advise shareholders of the percentage of dividends,
if any, subject to any federal tax.
 
   
Dividends and distributions for all of the other Funds are subject to federal
income tax, regardless of whether the distribution is made in cash or reinvested
in additional shares of a Fund. In certain states, a portion of the dividends
and distributions (depending on the sources of a Fund's income) may be exempt
from state and local taxes. Information regarding the tax status of income
dividends and capital gains distributions will be mailed to shareholders on or
before January 31st of each year. Account tax information will also be sent to
the IRS.
    
 
TAXATION OF THE FUNDS
   
The Funds may from year to year make the election permitted under section 853 of
the Internal Revenue Code to pass through such taxes to shareholders as a
foreign tax credit. If such an election is not made, any foreign taxes paid or
accrued will represent an expense to the Funds which will reduce their
investment income.
    
 
The Funds do not expect to pay any federal income or excise taxes because they
intend to meet certain requirements of the Internal Revenue Code. It is
important that the Funds meet these requirements so that any earnings on your
investment will not be taxed twice.
 
                               PERFORMANCE TERMS
 
This section will help you understand various terms that are commonly used to
describe a Fund's performance. You may see references to these terms in our
newsletters, advertisements and in media articles. Our newsletters and
advertisements may include comparisons of the Fund's performance to the
performance of other mutual funds,
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    49
    
<PAGE>   
 
mutual fund averages or recognized stock market indices. The Funds measure
performance in terms of yield.
 
YIELD shows the rate of income a Fund earns on its investments as a percentage
of the Fund's share price. It is calculated by dividing a Fund's net investment
income for a 30-day period (7-day period for the Money Market Funds) by the
average number of shares entitled to receive dividends and dividing the result
by the Fund's NAV per share at the end of such period. Yield does not include
changes in NAV.
 
Yields are calculated according to standardized SEC formulas and may not equal
the income on an investor's account. Yield is usually quoted on an annualized
basis. An annualized yield represents the amount you would earn if you remained
in a Fund for a year and that Fund continued to have the same yield for the
entire year.
 
EFFECTIVE YIELD is similar to yield in that it is calculated over the same time
frame, but instead the net investment income is compounded and then annualized.
Due to the compounding effect, the effective yield will normally be higher than
the yield.
 
TAX-EQUIVALENT YIELD OR TOTAL RETURN (for Janus Federal Tax-Exempt Fund and
Janus Tax-Exempt Money Market Fund) shows the before-tax yield or total return
that an investor would have to earn to equal the Funds' tax-free yield or total
return. It is calculated by dividing a Fund's tax-free yield or total return by
the result of one minus a stated federal tax rate.
 
   
CUMULATIVE TOTAL RETURN represents the actual rate of return on an investment
for a specified period. The Financial Highlights tables beginning on page 7 show
total return for a single fiscal period. Cumulative total return is generally
quoted for more than one year (e.g., the life of the Fund). A cumulative total
return does not show interim fluctuations in the value of an investment.
    
 
AVERAGE ANNUAL TOTAL RETURN represents the average annual percentage change of
an investment over a specified period. It is calculated by taking the cumulative
total return for the stated period and determining what constant annual return
would have produced the same cumulative return. Average annual returns for more
than one year tend to smooth out variations in a Fund's return and are not the
same as actual annual results.
 
THE FUNDS IMPOSE NO SALES OR OTHER CHARGES THAT WOULD AFFECT YIELD OR TOTAL
RETURN COMPUTATIONS. FUND PERFORMANCE FIGURES ARE BASED UPON HISTORICAL RESULTS
AND ARE NOT INTENDED TO INDICATE FUTURE PERFORMANCE. INVESTMENT RETURNS AND NET
ASSET VALUE WILL FLUCTUATE SO THAT AN INVESTOR'S SHARES, WHEN REDEEMED, MAY BE
WORTH MORE OR LESS THAN THEIR ORIGINAL COST.
 
   
 50   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
                                   APPENDIX A
 
GLOSSARY OF INVESTMENT TERMS
This glossary provides a more detailed description of some of the types of
securities and other instruments in which the Fixed-Income Funds may invest. The
Fixed-Income Funds may invest in these instruments to the extent permitted by
their investment objectives and policies. The Fixed-Income Funds are not limited
by this discussion and may invest in any other types of instruments not
precluded by the policies discussed elsewhere in this Prospectus. Please refer
to the SAI for a more detailed discussion of certain instruments.
 
I. EQUITY AND DEBT SECURITIES
   
BONDS are debt securities issued by a company, municipality, government or
government agency. The issuer of a bond is required to pay the holder the amount
of the loan (or par value of the bond) at a specified maturity and to make
scheduled interest payments.
    
 
CERTIFICATES OF PARTICIPATION ("COPS") are certificates representing an interest
in a pool of securities. Holders are entitled to a proportionate interest in the
underlying securities. Municipal lease obligations are often sold in the form of
COPs. See "Municipal lease obligations" below.
 
COMMERCIAL PAPER is a short-term debt obligation with a maturity ranging from 1
to 270 days issued by banks, corporations and other borrowers to investors
seeking to invest idle cash. For example, the Funds may purchase commercial
paper issued under Section 4(2) of the Securities Act of 1933.
 
COMMON STOCK represents a share of ownership in a company and usually carries
voting rights and earns dividends. Unlike preferred stock, dividends on common
stock are not fixed but are declared at the discretion of the issuer's board of
directors.
 
CONVERTIBLE SECURITIES are preferred stocks or bonds that pay a fixed dividend
or interest payment and are convertible into common stock at a specified price
or conversion ratio.
 
DEPOSITARY RECEIPTS are receipts for shares of a foreign-based corporation that
entitle the holder to dividends and capital gains on the underlying security.
Receipts include those issued by domestic banks (American Depositary Receipts),
foreign banks (Global or European Depositary Receipts) and broker-dealers
(depositary shares).
 
   
FIXED-INCOME SECURITIES are securities that pay a specified rate of return. The
term generally includes short- and long-term government, corporate and municipal
obligations that pay a specified rate of interest or coupons for a specified
period of time, and preferred stock, which pays fixed dividends. Coupon and
dividend rates may be fixed for the life of the issue or, in the case of
adjustable and floating rate securities, for a shorter period.
    
 
HIGH-YIELD/HIGH-RISK SECURITIES are securities that are rated below investment
grade by the primary rating agencies (e.g., BB or lower by Standard & Poor's and
Ba or lower
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    51
    
<PAGE>   
 
by Moody's). Other terms commonly used to describe such securities include
"lower rated bonds," "noninvestment grade bonds" and "junk bonds."
 
INDUSTRIAL DEVELOPMENT BONDS are revenue bonds that are issued by a public
authority but which may be backed only by the credit and security of a private
issuer and may involve greater credit risk. See "Municipal securities" below.
 
MORTGAGE- AND ASSET-BACKED SECURITIES are shares in a pool of mortgages or other
debt. These securities are generally pass-through securities, which means that
principal and interest payments on the underlying securities (less servicing
fees) are passed through to shareholders on a pro rata basis. These securities
involve prepayment risk, which is the risk that the underlying mortgages or
other debt may be refinanced or paid off prior to their maturities during
periods of declining interest rates. In that case, a portfolio manager may have
to reinvest the proceeds from the securities at a lower rate. Potential market
gains on a security subject to prepayment risk may be more limited than
potential market gains on a comparable security that is not subject to
prepayment risk.
 
MUNICIPAL LEASE OBLIGATIONS are revenue bonds backed by leases or installment
purchase contracts for property or equipment. Lease obligations may not be
backed by the issuing municipality's credit and may involve risks not normally
associated with general obligation bonds and other revenue bonds. For example,
their interest may become taxable if the lease is assigned and the holders may
incur losses if the issuer does not appropriate funds for the lease payments on
an annual basis, which may result in termination of the lease and possible
default.
 
MUNICIPAL SECURITIES are bonds or notes issued by a U.S. state or political
subdivision. A municipal security may be a general obligation backed by the full
faith and credit (i.e., the borrowing and taxing power) of a municipality or a
revenue obligation paid out of the revenues of a designated project, facility or
revenue source.
 
   
PASSIVE FOREIGN INVESTMENT COMPANIES (PFICS) are any foreign corporations which
generate certain amounts of passive income or hold certain amounts of assets for
the production of passive income. Passive income includes dividends, interest,
royalties, rents and annuities. To avoid taxes and interest that the Funds must
pay if these investments are profitable, the Funds may make various elections
permitted by the tax laws. These elections could require that the Funds
recognize taxable income, which in turn must be distributed, before the
securities are sold and before cash is received to pay the distributions.
    
 
PAY-IN-KIND BONDS are debt securities that normally give the issuer an option to
pay cash at a coupon payment date or give the holder of the security a similar
bond with the same coupon rate and a face value equal to the amount of the
coupon payment that would have been made.
 
PREFERRED STOCK is a class of stock that generally pays dividends at a specified
rate and has preference over common stock in the payment of dividends and
liquidation. Preferred stock generally does not carry voting rights.
 
REPURCHASE AGREEMENTS involve the purchase of a security by a Fund and a
simultaneous agreement by the seller (generally a bank or dealer) to repurchase
the
 
   
 52   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
security from the Fund at a specified date or upon demand. This technique offers
a method of earning income on idle cash. These securities involve the risk that
the seller will fail to repurchase the security, as agreed. In that case, a Fund
will bear the risk of market value fluctuations until the security can be sold
and may encounter delays and incur costs in liquidating the security.
 
REVERSE REPURCHASE AGREEMENTS involve the sale of a security by a Fund to
another party (generally a bank or dealer) in return for cash and an agreement
by the Fund to buy the security back at a specified price and time. This
technique will be used primarily to provide cash to satisfy unusually high
redemption requests, or for other temporary or emergency purposes.
 
RULE 144A SECURITIES are securities that are not registered for sale to the
general public under the Securities Act of 1933, but that may be resold to
certain institutional investors.
 
STANDBY COMMITMENTS are obligations purchased by a Fund from a dealer that give
the Fund the option to sell a security to the dealer at a specified price.
 
STEP COUPON BONDS are debt securities that trade at a discount from their face
value and pay coupon interest. The discount from the face value depends on the
time remaining until cash payments begin, prevailing interest rates, liquidity
of the security and the perceived credit quality of the issuer.
 
STRIP BONDS are debt securities that are stripped of their interest (usually by
a financial intermediary) after the securities are issued. The market value of
these securities generally fluctuates more in response to changes in interest
rates than interest-paying securities of comparable maturity.
 
TENDER OPTION BONDS are generally long-term securities that are coupled with an
option to tender the securities to a bank, broker-dealer or other financial
institution at periodic intervals and receive the face value of the bond. This
type of security is commonly used as a means of enhancing the security's
liquidity.
 
U.S. GOVERNMENT SECURITIES include direct obligations of the U.S. government
that are supported by its full faith and credit. Treasury bills have initial
maturities of less than one year, Treasury notes have initial maturities of one
to ten years and Treasury bonds may be issued with any maturity but generally
have maturities of at least ten years. U.S. government securities also include
indirect obligations of the U.S. government that are issued by federal agencies
and government sponsored entities. Unlike Treasury securities, agency securities
generally are not backed by the full faith and credit of the U.S. government.
Some agency securities are supported by the right of the issuer to borrow from
the Treasury, others are supported by the discretionary authority of the U.S.
government to purchase the agency's obligations and others are supported only by
the credit of the sponsoring agency.
 
VARIABLE AND FLOATING RATE SECURITIES have variable or floating rates of
interest and, under certain limited circumstances, may have varying principal
amounts. These securities pay interest at rates that are adjusted periodically
according to a specified formula, usually with reference to some interest rate
index or market interest rate. The floating rate tends to decrease the
security's price sensitivity to changes in interest rates.
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    53
    
<PAGE>   
 
WARRANTS are securities, typically issued with preferred stock or bonds, that
give the holder the right to buy a proportionate amount of common stock at a
specified price, usually at a price that is higher than the market price at the
time of issuance of the warrant. The right may last for a period of years or
indefinitely.
 
WHEN-ISSUED, DELAYED DELIVERY AND FORWARD TRANSACTIONS generally involve the
purchase of a security with payment and delivery at some time in the
future - i.e., beyond normal settlement. The Funds do not earn interest on such
securities until settlement and bear the risk of market value fluctuations in
between the purchase and settlement dates. New issues of stocks and bonds,
private placements and U.S. government securities may be sold in this manner.
 
ZERO COUPON BONDS are debt securities that do not pay regular interest at
regular intervals, but are issued at a discount from face value. The discount
approximates the total amount of interest the security will accrue from the date
of issuance to maturity. The market value of these securities generally
fluctuates more in response to changes in interest rates than interest-paying
securities.
 
II. FUTURES, OPTIONS AND OTHER DERIVATIVES
   
FORWARD CONTRACTS are contracts to purchase or sell a specified amount of a
financial instrument for an agreed upon price at a specified time. Forward
contracts are not currently exchange traded and are typically negotiated on an
individual basis. The Funds may enter into forward currency contracts to hedge
against declines in the value of securities denominated in, or whose value is
tied to, a currency other than the U.S. dollar or to reduce the impact of
currency appreciation on purchases of such securities. They may also enter into
forward contracts to purchase or sell securities or other financial indices.
    
 
FUTURES CONTRACTS are contracts that obligate the buyer to receive and the
seller to deliver an instrument or money at a specified price on a specified
date. The Funds may buy and sell futures contracts on foreign currencies,
securities and financial indices including interest rates or an index of U.S.
government, foreign government, equity or fixed-income securities. The Funds may
also buy options on futures contracts. An option on a futures contract gives the
buyer the right, but not the obligation, to buy or sell a futures contract at a
specified price on or before a specified date. Futures contracts and options on
futures are standardized and traded on designated exchanges.
 
INDEXED/STRUCTURED SECURITIES are typically short- to intermediate-term debt
securities whose value at maturity or interest rate is linked to currencies,
interest rates, equity securities, indices, commodity prices or other financial
indicators. Such securities may be positively or negatively indexed (i.e. their
value may increase or decrease if the reference index or instrument
appreciates). Indexed/structured securities may have return characteristics
similar to direct investments in the underlying instruments and may be more
volatile than the underlying instruments. A Fund bears the market risk of an
investment in the underlying instruments, as well as the credit risk of the
issuer.
 
INTEREST RATE SWAPS involve the exchange by two parties of their respective
commitments to pay or receive interest (e.g., an exchange of floating rate
payments for fixed rate payments).
 
   
 54   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
INVERSE FLOATERS are debt instruments whose interest rate bears an inverse
relationship to the interest rate on another instrument or index. For example,
upon reset the interest rate payable on a security may go down when the
underlying index has risen. Certain inverse floaters may have an interest rate
reset mechanism that multiplies the effects of change in the underlying index.
Such mechanism may increase the volatility of the security's market value.
 
OPTIONS are the right, but not the obligation, to buy or sell a specified amount
of securities or other assets on or before a fixed date at a predetermined
price. The Funds may purchase and write put and call options on securities,
securities indices and foreign currencies.
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    55
    
<PAGE>   
 
                                   APPENDIX B
 
EXPLANATION OF RATING CATEGORIES
   
The following is a description of credit ratings issued by two of the major
credit ratings agencies. Credit ratings evaluate only the safety of principal
and interest payments, not the market value risk of lower quality securities.
Credit rating agencies may fail to change credit ratings to reflect subsequent
events on a timely basis. Although Janus Capital considers security ratings when
making investment decisions, it also performs its own investment analysis and
does not rely solely on the ratings assigned by credit agencies.
    
 
STANDARD & POOR'S RATINGS SERVICES
 
   
<TABLE>
<S>                  <C>
BOND RATING          EXPLANATION
- ------------------------------------------------------------------------
INVESTMENT GRADE
AAA                  Highest rating; extremely strong capacity to pay
                     principal and interest.
AA                   High quality; very strong capacity to pay principal
                     and interest.
A                    Strong capacity to pay principal and interest;
                     somewhat more susceptible to the adverse effects of
                     changing circumstances and economic conditions.
BBB                  Adequate capacity to pay principal and interest;
                     normally exhibit adequate protection parameters,
                     but adverse economic conditions or changing
                     circumstances more likely to lead to a weakened
                     capacity to pay principal and interest than for
                     higher rated bonds.
NON-INVESTMENT GRADE
BB, B,               Predominantly speculative with respect to the
CCC, CC, C           issuer's capacity to meet required interest and
                     principal payments. BB - lowest degree of
                     speculation; C - the highest degree of speculation.
                     Quality and protective characteristics outweighed
                     by large uncertainties or major risk exposure to
                     adverse conditions.
D                    In default.
- ------------------------------------------------------------------------
</TABLE>
    
 
   
 56   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
MOODY'S INVESTORS SERVICE, INC.
 
   
<TABLE>
<S>                  <C>
BOND RATING          EXPLANATION
- ------------------------------------------------------------------------
INVESTMENT GRADE
Aaa                  Highest quality, smallest degree of investment
                     risk.
Aa                   High quality; together with Aaa bonds, they compose
                     the high-grade bond group.
A                    Upper-medium grade obligations; many favorable
                     investment attributes.
Baa                  Medium-grade obligations; neither highly protected
                     nor poorly secured. Interest and principal appear
                     adequate for the present but certain protective
                     elements may be lacking or may be unreliable over
                     any great length of time.
NON-INVESTMENT GRADE
Ba                   More uncertain, with speculative elements.
                     Protection of interest and principal payments not
                     well safeguarded during good and bad times.
B                    Lack characteristics of desirable investment;
                     potentially low assurance of timely interest and
                     principal payments or maintenance of other contract
                     terms over time.
Caa                  Poor standing, may be in default; elements of
                     danger with respect to principal or interest
                     payments.
Ca                   Speculative in a high degree; could be in default
                     or have other marked shortcomings.
C                    Lowest-rated; extremely poor prospects of ever
                     attaining investment standing.
- ------------------------------------------------------------------------
</TABLE>
    
 
   
Unrated securities will be treated as noninvestment grade securities unless a
portfolio manager determines that such securities are the equivalent of
investment grade securities. Securities that have received ratings from more
than one agency are considered investment grade if at least one agency has rated
the security investment grade.
    
 
   
JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998    57
    
<PAGE>   
 
SECURITIES HOLDINGS BY RATING CATEGORY
   
[TO BE FILED BY AMENDMENT]
    
 
   
During the fiscal period ended October 31, 1997, the percentage of securities
holdings for Janus Flexible Income Fund and Janus High-Yield Fund by rating
category based upon a weighted monthly average was:
    
 
   
<TABLE>
<S>                                        <C>
BONDS - S&P RATING                         JANUS FLEXIBLE INCOME FUND
- ---------------------------------------------------------------------
AAA                                                      %
AA                                                       %
A                                                        %
BBB                                                      %
BB                                                       %
B                                                        %
CCC                                                      %
CC                                                       %
C                                                        %
Preferred Stock                                          %
Cash and Options                                         %
- ---------------------------------------------------------------------
TOTAL                                                 100%
- ---------------------------------------------------------------------
BONDS - S&P RATING                              JANUS HIGH-YIELD FUND
- ---------------------------------------------------------------------
AAA                                                        %
AA                                                         %
A                                                          %
BBB                                                        %
BB                                                         %
B                                                          %
CCC                                                        %
CC                                                         %
C                                                          %
Preferred Stock                                            %
Cash and Options                                           %
- ---------------------------------------------------------------------
TOTAL                                                   100%
- ---------------------------------------------------------------------
</TABLE>
    
 
   
No other Fund held 5% or more of its assets in bonds rated below investment
grade for the fiscal period ended October 31, 1997.
    
 
   
 58   JANUS INCOME FUNDS COMBINED PROSPECTUS                   FEBRUARY 17, 1998
    
<PAGE>   
 
   
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<PAGE>   
 
   
                       This page intentionally left blank
    

<PAGE>   
 
                               Janus Venture Fund
 
                              100 Fillmore Street
                             Denver, CO 80206-4928
                                 1-800-525-3713
   
                              http://www.Janus.com
    
 
   
                               FEBRUARY 17, 1998
    
 
   
Janus Venture Fund (the "Fund") is a no-load, diversified mutual fund that seeks
capital appreciation. The Fund normally invests at least 50% of its equity
assets in securities of small-sized companies.
    
 
   
THE FUND HAS DISCONTINUED PUBLIC SALES OF ITS SHARES TO NEW INVESTORS, BUT
SHAREHOLDERS WHO MAINTAIN OPEN FUND ACCOUNTS ARE STILL ABLE TO MAKE INVESTMENTS
IN THE FUND AND REINVEST ANY DIVIDENDS AND CAPITAL GAINS DISTRIBUTIONS. CURRENT
SHAREHOLDERS MAY ALSO OPEN ADDITIONAL FUND ACCOUNTS UNDER CERTAIN CONDITIONS. IF
A FUND ACCOUNT IS CLOSED, HOWEVER, ADDITIONAL INVESTMENTS IN THE FUND MAY NOT BE
POSSIBLE. For complete information on how to purchase, exchange and sell shares,
please see the Shareholder's Manual beginning on page 16. The Fund may resume
sale of its shares to new investors in the future, although it has no current
intention to do so.
    
 
   
The Fund is a portfolio of Janus Investment Fund (the "Trust"), which is
registered with the Securities and Exchange Commission ("SEC") as an open-end
management investment company. This Prospectus contains information about the
Fund that you should consider before investing. Please read it carefully and
keep it for future reference.
    
 
   
Additional information about the Fund is contained in a Statement of Additional
Information ("SAI") filed with the SEC. The SAI dated February 17, 1998, is
incorporated by reference into this Prospectus. For a copy of the SAI, write or
call the Fund at the address or phone number listed above. The SEC maintains a
Web site located at http://www.sec.gov that contains the SAI, material
incorporated by reference, and other information regarding the Fund.
    
 
   
THESE SECURITIES HAVE NOT BEEN APPROVED BY THE SEC NOR HAS THE SEC PASSED ON THE
ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A
CRIMINAL OFFENSE.
    
 
   
THIS PROSPECTUS DOES NOT CONSTITUTE AN OFFER TO SELL SECURITIES IN ANY STATE OR
OTHER JURISDICTION TO ANY PERSON TO WHOM IT IS UNLAWFUL TO MAKE SUCH AN OFFER IN
SUCH STATE OR OTHER JURISDICTION.
    
 
   
JANUS VENTURE FUND PROSPECTUS                             FEBRUARY 17, 1998    1
    
<PAGE>   
 
                                    CONTENTS
 
   
<TABLE>
<S>                                            <C>
THE FUND AT A GLANCE
Brief description of the Fund................    3
EXPENSE INFORMATION
The Fund's annual operating expenses.........    4
Financial Highlights - a summary of financial
  data.......................................    5
THE FUND IN DETAIL
Investment Objective.........................    8
General Portfolio Policies...................   10
Additional Risk Factors......................   12
PERFORMANCE TERMS
An Explanation of Performance Terms..........   15
SHAREHOLDER'S MANUAL
Types of Account Ownership...................   17
How to Open Your Janus Account...............   18
How to Purchase Shares.......................   18
How to Exchange Shares.......................   20
How to Redeem Shares.........................   21
Shareholder Services and Account Policies....   23
MANAGEMENT OF THE FUND
Investment Adviser and Portfolio Managers....   27
Personal Investing...........................   28
Management Expenses..........................   28
Portfolio Transactions.......................   28
Other Service Providers......................   29
Other Information............................   29
DISTRIBUTIONS AND TAXES
Distributions................................   31
Taxes........................................   32
APPENDIX A
Glossary of Investment Terms.................   33
</TABLE>
    
 
   
 2   JANUS VENTURE FUND PROSPECTUS                             FEBRUARY 17, 1998
    
<PAGE>   
 
                              THE FUND AT A GLANCE
 
   
This section provides you with a brief overview of the Fund and its investment
emphasis. A more detailed discussion of the Fund's investment objective and
policies begins on page 8 and complete information on how to purchase, redeem
and exchange shares begins on page 18.
    
 
   
FUND FOCUS:
    
   
A diversified fund that seeks capital appreciation by investing primarily in
common stocks, with an emphasis on securities of small-sized companies.
    
 
   
SHAREHOLDER'S INVESTMENT HORIZON:
    
The Fund is designed for long-term investors who seek capital appreciation and
who can tolerate the greater risks associated with investments in foreign and
domestic common stocks. The Fund is not designed as a short-term trading vehicle
and should not be relied upon for short-term financial needs.
 
   
FUND ADVISER:
    
   
Janus Capital Corporation ("Janus Capital") serves as the Fund's investment
adviser. Janus Capital has been in the investment advisory business for over 27
years and currently manages approximately $70 billion in assets.
    
 
   
MANAGEMENT TEAM:
    
James P. Craig
   
William H. Bales
    
Jonathan D. Coleman
 
   
FUND INCEPTION:
    
April 30, 1985
 
   
JANUS VENTURE FUND PROSPECTUS                             FEBRUARY 17, 1998    3
    
<PAGE>   
 
                              EXPENSE INFORMATION
 
The tables and example below are designed to assist you in understanding the
various costs and expenses that you will bear directly or indirectly as an
investor in the Fund. Shareholder Transaction Expenses are fees charged directly
to your individual account when you buy, sell or exchange shares. The table
below shows that you pay no such fees. Annual Fund Operating Expenses are paid
out of the Fund's assets and include fees for portfolio management, maintenance
of shareholder accounts, shareholder servicing, accounting and other services.
 
   
    SHAREHOLDER TRANSACTION EXPENSES
    
 
   
<TABLE>
         <S>                                                  <C>
         Maximum sales load imposed on purchases              None
         Maximum sales load imposed on reinvested dividends   None
         Deferred sales charges on redemptions                None
         Redemption fees*                                     None
         Exchange fee                                         None
</TABLE>
    
 
   
    * There is an $8 service fee for redemptions by wire.
    
 
   
ANNUAL OPERATING EXPENSES(1)
    
   
(expressed as a percentage of average net assets)
 
<TABLE>
<S>                                                    <C>
- ------------------------------------------------------------
Management Fee                                         0.68%
Other Expenses                                         0.26%
- ------------------------------------------------------------
Total Fund Operating Expenses                          0.94%
- ------------------------------------------------------------
</TABLE>
    
 
   
(1)Annual Operating Expenses are based on expenses before expense offset
   arrangements for the fiscal year ended October 31, 1997.
    
 
   
EXAMPLE
    
 
   
<TABLE>
<CAPTION>
- -------------------------------------------------------------------------
                                       1 YEAR  3 YEARS  5 YEARS  10 YEARS
- -------------------------------------------------------------------------
<S>                                    <C>     <C>      <C>      <C>
Assume you invest $1,000, the Fund
returns 5% annually and its expense
ratio remains as listed above. This
example shows the operating expenses
that you would indirectly bear as an
investor in the Fund.                   $10      $30      $52      $115
</TABLE>
    
 
- -------------------------------------------------------------------------
 
THE EXAMPLE SHOULD NOT BE CONSIDERED A REPRESENTATION OF PAST OR FUTURE RETURNS
OR EXPENSES WHICH MAY BE MORE OR LESS THAN THOSE SHOWN.
 
   
 4   JANUS VENTURE FUND PROSPECTUS                             FEBRUARY 17, 1998
    
<PAGE>   
 
                              FINANCIAL HIGHLIGHTS
 
   
Unless otherwise noted, the information below is for fiscal periods ending on
October 31 of each year. The accounting firm of Price Waterhouse LLP has audited
the Fund's financial statements beginning with the year ended October 31, 1990.
Their report is included in the Fund's Annual Report, which is incorporated by
reference into the SAI.
    
   
<TABLE>
<CAPTION>
                                               1997+       1996       1995       1994
<S>                                           <C>        <C>        <C>        <C>
- --------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD                  $59.53     $52.86     $53.25
- --------------------------------------------------------------------------------------
  INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income/(loss)                              --       0.05       0.11
 3. Net gains or (losses) on securities
    (both realized and unrealized)                          5.09       9.49       4.40
- --------------------------------------------------------------------------------------
 4. Total from investment operations                        5.09       9.54       4.51
- --------------------------------------------------------------------------------------
  LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)                (0.01)     (0.03)     (0.53)
 6. Distributions (from capital gains)                    (7.45)     (2.84)     (4.37)
- --------------------------------------------------------------------------------------
 7. Total distributions                                   (7.46)     (2.87)     (4.90)
- --------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                        $57.16     $59.53     $52.86
- --------------------------------------------------------------------------------------
 9. Total return*                                          9.28%     19.24%      9.23%
- --------------------------------------------------------------------------------------
10. Net assets, end of period (in millions)               $1,741     $1,753     $1,550
11. Average net assets for the period (in
    millions)                                             $1,823     $1,613     $1,563
12. Ratio of gross expenses to average net
    assets**                                               0.89%      0.92%        N/A
13. Ratio of net expenses to average net
    assets**                                               0.88%      0.91%      0.96%
14. Ratio of net investment income/(loss) to
    average net assets**                                 (0.33%)      0.29%      0.27%
15. Portfolio turnover rate**                               136%       113%       114%
16. Average commission rate                               $.0382        N/A        N/A
- --------------------------------------------------------------------------------------
 
<CAPTION>
                                                1993     1992(1)
<S>                                           <C>        <C>
- --------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD       $47.74     $45.96
- --------------------------------------------------------------------------------------
  INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income/(loss)                 0.66       0.17
 3. Net gains or (losses) on securities
    (both realized and unrealized)               6.72       1.61
- --------------------------------------------------------------------------------------
 4. Total from investment operations             7.38       1.78
- --------------------------------------------------------------------------------------
  LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)     (1.16)         --
 6. Distributions (from capital gains)         (0.71)         --
- --------------------------------------------------------------------------------------
 7. Total distributions                        (1.87)         --
- --------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD             $53.25     $47.74
- --------------------------------------------------------------------------------------
 9. Total return*                              15.76%      3.87%
- --------------------------------------------------------------------------------------
10. Net assets, end of period (in millions)    $1,837     $1,545
11. Average net assets for the period (in
    millions)                                  $1,793     $1,496
12. Ratio of gross expenses to average net
    assets**                                      N/A        N/A
13. Ratio of net expenses to average net
    assets**                                    0.97%      1.07%
14. Ratio of net investment income/(loss) to
    average net assets**                        1.29%      1.32%
15. Portfolio turnover rate**                    139%       124%
16. Average commission rate                       N/A        N/A
- --------------------------------------------------------------------------------------
</TABLE>
    
 
(1) Fiscal period from August 1, 1992 to October 31, 1992.
   
 * Total return is not annualized for periods of less than one full year.
    
** Annualized for periods of less than one full year.
   
 + [To be filed by Amendment]
    
 
   
JANUS VENTURE FUND PROSPECTUS                             FEBRUARY 17, 1998    5
    
<PAGE>   
 
   
(continued)
    
 
   
<TABLE>
<CAPTION>
                                                   1992(1)    1991(1)    1990(1)    1989(1)    1988(1)
<S>                                                <C>        <C>        <C>        <C>        <C>
- ------------------------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD            $45.05     $37.90     $36.97    $28.11      $34.63
- ------------------------------------------------------------------------------------------------------
  INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income/(loss)                      0.36       0.44       0.28      0.33        1.50
 3. Net gains or (losses) on securities (both
    realized and unrealized)                          4.23       7.71       3.44     10.05      (3.70)
- ------------------------------------------------------------------------------------------------------
 4. Total from investment operations                  4.59       8.15       3.72     10.38      (2.20)
- ------------------------------------------------------------------------------------------------------
  LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)          (0.25)     (0.11)     (0.44)    (1.52)      (0.15)
 6. Distributions (from capital gains)              (3.43)     (0.89)     (2.35)        --      (4.17)
- ------------------------------------------------------------------------------------------------------
 7. Total distributions                             (3.68)     (1.00)     (2.79)    (1.52)      (4.32)
- ------------------------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                  $45.96     $45.05     $37.90    $36.97      $28.11
- ------------------------------------------------------------------------------------------------------
 9. Total return*                                    9.90%     22.28%     10.46%    38.73%     (4.56%)
- ------------------------------------------------------------------------------------------------------
10. Net assets, end of period (in millions)         $1,510       $893       $256       $58         $34
11. Average net assets for the period (in
    millions)                                       $1,382       $427       $127       $40         $35
12. Ratio of gross expenses to average net
    assets**                                           N/A        N/A        N/A       N/A         N/A
13. Ratio of net expenses to average net assets**    1.00%      1.04%      1.16%     1.28%       1.41%
14. Ratio of net investment income/(loss) to
    average net assets**                             1.20%      2.10%      1.24%     1.10%       5.11%
15. Portfolio turnover rate**                         166%       167%       184%      219%        299%
16. Average commission rate                            N/A        N/A        N/A       N/A         N/A
- ------------------------------------------------------------------------------------------------------
</TABLE>
    
 
   
(1) Fiscal year ended on July 31st of each year.
    
 * Total return is not annualized for periods of less than one full year.
** Annualized for periods of less than one full year.
 
   
 6   JANUS VENTURE FUND PROSPECTUS                             FEBRUARY 17, 1998
    
<PAGE>   
 
                               UNDERSTANDING THE
   
                              FINANCIAL HIGHLIGHTS
    
 
This section is designed to help you better understand the information
summarized in the Financial Highlights table. The table contains important
historical operating information that may be useful in making your investment
decision or understanding how your investment has performed. The Fund's Annual
Report contains additional information about the Fund's performance, including a
comparison to an appropriate securities index. For a copy of the Annual Report,
call 1-800-525-8983.
 
NET ASSET VALUE ("NAV") is the value of a single share of the Fund. It is
computed by adding the value of all of the Fund's investments and other assets,
subtracting any liabilities and dividing the result by the number of shares
outstanding. The difference between line 1 and line 8 in the Financial
Highlights table represents the change in value of a Fund share over the fiscal
period, but not its total return.
 
NET INVESTMENT INCOME is the per share amount of dividends and interest income
earned on securities held by the Fund, less Fund expenses. DIVIDENDS (FROM NET
INVESTMENT INCOME) are the per share amount that the Fund paid from net
investment income.
 
NET GAINS OR (LOSSES) ON SECURITIES is the per share increase or decrease in
value of the securities the Fund holds. A gain (or loss) is realized when
securities are sold. A gain (or loss) is unrealized when securities increase or
decrease in value but are not sold. DISTRIBUTIONS (FROM CAPITAL GAINS) are the
per share amount that the Fund paid from net realized gains.
 
TOTAL RETURN is the percentage increase or decrease in the value of an
investment over a stated period of time. A total return percentage includes both
changes in NAV and income. For the purpose of calculating total return, it is
assumed that dividends and distributions are reinvested at the NAV on the day of
the distribution. THE FUND'S TOTAL RETURN CANNOT BE COMPUTED DIRECTLY FROM THE
FINANCIAL HIGHLIGHTS TABLE.
 
   
RATIO OF GROSS EXPENSES TO AVERAGE NET ASSETS is the total of the Fund's
operating expenses before expense offset arrangements divided by its average net
assets for the stated period. RATIO OF NET EXPENSES TO AVERAGE NET ASSETS
reflects reductions in the Fund's expenses through the use of brokerage
commissions and uninvested cash balances earning interest or balance credits.
    
 
RATIO OF NET INVESTMENT INCOME TO AVERAGE NET ASSETS is the Fund's net
investment income divided by its average net assets for the stated period.
 
PORTFOLIO TURNOVER RATE is a measure of the amount of the Fund's buying and
selling activity. It is computed by dividing total purchases or sales, whichever
is less, by the average monthly market value of the Fund's portfolio securities.
 
   
JANUS VENTURE FUND PROSPECTUS                             FEBRUARY 17, 1998    7
    
<PAGE>   
 
   
AVERAGE COMMISSION RATE is the total of the Fund's agency commissions paid on
equity securities trades divided by the number of shares purchased and sold.
    
 
   
                               THE FUND IN DETAIL
    
 
   
This section takes a closer look at the Fund's investment objective, policies
and the securities in which it invests. Policies that are noted as "fundamental"
cannot be changed without a shareholder vote. All other policies, including the
Fund's investment objective, are not fundamental and may be changed by the
Fund's Trustees without a shareholder vote. You will be notified of any such
changes that are material.
    
 
   
You should carefully consider your own investment goals, time horizon (the
amount of time you plan to hold shares of the Fund) and risk tolerance before
investing in the Fund. If there is a material change in the Fund's objective or
policies, you should consider whether the Fund remains an appropriate investment
for you.
    
 
   
Please carefully review the "Additional Risk Factors" section of this Prospectus
for a more detailed discussion of the risks associated with certain investment
techniques and refer to Appendix A for a more detailed description of investment
terms used throughout this Prospectus.
    
 
INVESTMENT OBJECTIVE
The investment objective of the Fund is capital appreciation. The Fund pursues
its objective by normally investing at least 50% of its equity assets in
securities issued by small-sized companies. Small-sized companies are those who
have market capitalizations of less than $1 billion or annual gross revenues of
less than $500 million. Companies whose capitalization or revenues fall outside
these ranges after the Fund's initial purchase continue to be considered
small-sized for the purposes of this policy. Subject to the above policy, the
Fund may also invest in larger companies.
 
TYPES OF INVESTMENTS
   
The Fund invests primarily in common stocks with an emphasis on securities of
small-sized companies. The Fund may also invest in larger companies with strong
growth potential or relatively well-known and large companies with potential for
capital appreciation. The Fund may invest to a lesser degree in other types of
securities including preferred stocks, warrants, convertible securities and debt
securities. The Fund may invest up to 25% of its assets in mortgage- and
asset-backed securities, up to 10% of its assets in zero coupon, pay-in-kind and
step coupon securities, and without limit in indexed/structured securities. The
Fund will invest less than 35% of its assets in high-yield/high-risk securities.
The Fund may also purchase high-grade commercial paper, certificates of deposit,
and repurchase agreements. Such securities may offer growth potential because of
anticipated changes in interest rates, credit standing, currency relationships
or other factors. The Fund may also invest in short-term debt securities,
including money market funds managed by Janus Capital, as a means of receiving a
return on idle cash.
    
 
   
 8   JANUS VENTURE FUND PROSPECTUS                             FEBRUARY 17, 1998
    
<PAGE>   
 
   
When the Fund's portfolio managers believe that market conditions are not
favorable for profitable investing or when the portfolio managers are otherwise
unable to locate favorable investment opportunities, the Fund's investments may
be hedged to a greater degree and/or its cash or similar investments may
increase. In other words, the Fund does not always stay fully invested in stocks
and bonds. Cash or similar investments are a residual - they represent the
assets that remain after the portfolio managers have committed available assets
to desirable investment opportunities. When the Fund is hedged or its cash
position increases, it might not participate in stock market advances or
declines to the extent that it would if it was not hedged or it remained more
fully invested in common stocks.
    
 
   
The Fund may invest without limit in foreign equity and debt securities. The
Fund may invest directly in foreign securities denominated in a foreign currency
and not publicly traded in the United States. Other ways of investing in foreign
securities include depositary receipts or shares, and passive foreign investment
companies. The Fund may use options, futures and other types of derivatives for
hedging purposes or for non-hedging purposes such as seeking to enhance return.
See "Additional Risk Factors" on page 12. The Fund may purchase securities on a
when-issued, delayed delivery or forward commitment basis.
    
 
THE FOLLOWING QUESTIONS ARE DESIGNED TO HELP YOU BETTER UNDERSTAND AN INVESTMENT
IN THE FUND.
 
   
Q:   HOW ARE COMMON STOCKS SELECTED?
    
 
     
 
   
A:   The Fund may invest substantially all of its assets in common stocks to the
     extent its portfolio managers believe that the relevant market environment
     favors profitable investing in those securities. The portfolio managers
generally take a "bottom up" approach to building the portfolio. In other words,
they seek to identify individual companies with earnings growth potential that
may not be recognized by the market at large. Although themes may emerge in the
Fund, securities are generally selected without regard to any defined industry
sector or other similarly defined selection procedure. Realization of income is
not a significant investment consideration. Any income realized on the Fund's
investments will be incidental to its objective.

   
Q:   ARE THE SAME CRITERIA USED
     TO SELECT FOREIGN SECURITIES? 
         
     
 
   
A:   Generally, yes. The portfolio managers seek companies that meet their
     selection criteria regardless of country of organization or place of
     principal business activity. Foreign securities are generally selected on a
stock-by-stock basis without regard to any defined allocation among countries or
geographic regions. However, certain factors such as expected levels of
inflation, government policies influencing business conditions, the outlook for
currency relationships, and prospects for economic growth among countries,
regions or geographic areas may warrant greater consideration in selecting
foreign securities. See "Additional Risk Factors" on page 12.
    
 
   
JANUS VENTURE FUND PROSPECTUS                             FEBRUARY 17, 1998    9
    
<PAGE>   
 
   
Q:   WHAT IS THE MAIN RISK OF INVESTING
     IN THE FUND?
         

    

 
   
A:   Since the Fund invests primarily in common stocks, the fundamental risk is
     that the value of the stocks it holds might decrease. Stock values may
     fluctuate in response to the activities of an individual company or in
response to general market and/or economic conditions. Historically, common
stocks have provided greater long-term returns and have entailed greater
short-term risks than other investment choices. Smaller or newer issuers, such
as those in which the Fund invests, are more likely to realize more substantial
growth as well as suffer more significant losses than larger or more established
issuers. Investments in such companies can be both more volatile and more
speculative. See "Additional Risk Factors" on page 12.
    
 
   
Q:   WHAT IS MEANT BY
     "MARKET CAPITALIZATION"?
    
     
 
   
A:   Market capitalization is the most commonly used measure of the size and
     value of a company. It is computed by multiplying the current market price
     of a share of the company's stock by the total number of its shares
outstanding. As noted previously, market capitalization and annual gross
revenues are important investment criteria for the Fund.
 
   
Q:   HOW DOES THE FUND
     TRY TO REDUCE RISK?
    
     
 
   
A:   Diversification of the Fund's assets reduces the effect of any single
     holding on its overall portfolio value. The Fund may also use futures,
     options and other derivative instruments to protect its portfolio from
movements in securities prices and interest rates. The Fund may use a variety of
currency hedging techniques, including forward currency contracts, to manage
exchange rate risk. See "Additional Risk Factors" on page 12. To the extent that
the Fund holds a larger cash position, it might not participate in market
declines to the same extent as if it had remained more fully invested in common
stocks.
    
 
GENERAL PORTFOLIO POLICIES
In investing its portfolio assets, the Fund will follow the general policies
listed below. The percentage limitations included in these policies and
elsewhere in this Prospectus apply only at the time of purchase of the security.
For example, if the Fund exceeds a limit as a result of market fluctuations or
the sale of other securities, it will not be required to dispose of any
securities.
 
   
 10   JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998
    
<PAGE>   
 
DIVERSIFICATION
The Investment Company Act of 1940 (the "1940 Act") classifies investment
companies as either diversified or nondiversified. The Fund qualifies as a
diversified fund under the 1940 Act and is subject to the following
requirements:
 
- - As a fundamental policy, the Fund may not own more than 10% of the outstanding
  voting shares of any issuer.
 
- - As a fundamental policy, with respect to 75% of its total assets, the Fund
  will not purchase a security of any issuer (other than cash items and U.S.
  government securities, as defined in the 1940 Act) if such purchase would
  cause the Fund's holdings of that issuer to amount to more than 5% of the
  Fund's total assets.
 
- - The Fund will invest no more than 25% of its total assets in a single issuer
  (other than U.S. government securities).
 
INDUSTRY CONCENTRATION
As a fundamental policy, the Fund will not invest 25% or more of its total
assets in any particular industry (excluding U.S. government securities).
 
PORTFOLIO TURNOVER
The Fund generally intends to purchase securities for long-term investment
rather than short-term gains. However, short-term transactions may result from
liquidity needs, securities having reached a price or yield objective, changes
in interest rates or the credit standing of an issuer, or by reason of economic
or other developments not foreseen at the time of the investment decision.
Changes are made in the Fund's portfolio whenever its portfolio managers believe
such changes are desirable. Portfolio turnover rates are generally not a factor
in making buy and sell decisions.
 
   
To a limited extent, the Fund may purchase securities in anticipation of
relatively short-term price gains. The Fund may also sell one security and
simultaneously purchase the same or a comparable security to take advantage of
short-term differentials in bond yields or securities prices. Increased
portfolio turnover may result in higher costs for brokerage commissions, dealer
mark-ups and other transaction costs and may also result in taxable capital
gains.
    
 
ILLIQUID INVESTMENTS
   
The Fund may invest up to 15% of its net assets in illiquid investments,
including restricted securities or private placements that are not deemed to be
liquid by Janus Capital. If illiquid securities exceed 15% of net assets after
the time of purchase, the Fund will take steps to reduce in an orderly fashion
its holdings of illiquid securities. An illiquid investment is a security or
other position that cannot be disposed of quickly in the normal course of
business. Some securities cannot be sold to the U.S. public because of their
terms or because of SEC regulations. Janus Capital will follow guidelines
established by the Fund's Trustees in making liquidity determinations for Rule
144A securities and certain other securities, including privately placed
commercial paper.
    
 
   
JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998    11
    
<PAGE>   
 
BORROWING AND LENDING
The Fund may borrow money and lend securities or other assets, as follows:
 
- - The Fund may borrow money for temporary or emergency purposes in amounts up to
  25% of its total assets.
 
   
- - The Fund may mortgage or pledge securities as collateral for borrowings in
  amounts up to 15% of its net assets.
    
 
- - As a fundamental policy, the Fund may lend securities or other assets if, as a
  result, no more than 25% of its total assets would be lent to other parties.
 
   
Under the terms of an exemptive order received from the SEC, the Fund may borrow
money from or lend money to other funds that permit such transactions and for
which Janus Capital serves as investment adviser. All such borrowing and lending
will be subject to the above limits.
    
 
ADDITIONAL RISK FACTORS
INVESTMENTS IN SMALLER COMPANIES
   
The Fund may invest in companies that have relatively small revenues, have a
small share of the market for their products or services, or have limited
geographic or product markets. Smaller or newer companies may suffer more
significant losses as well as realize more substantial growth than larger or
more established issuers. Small companies may lack depth of management, they may
be unable to generate internally funds necessary for growth or potential
development or to generate such funds through external financing on favorable
terms, or they may be developing or marketing new products or services for which
markets are not yet established and may never become established. In addition,
such companies may be insignificant factors in their industries and may become
subject to intense competition from larger companies. Securities of small
companies held by the Fund may have limited trading markets that may be subject
to wide price fluctuations. Investments in such companies tend to be more
volatile and somewhat more speculative.
    
 
SPECIAL SITUATIONS
The Fund may invest in "special situations" from time to time. A special
situation arises when, in the opinion of the Fund's portfolio managers, the
securities of a particular issuer will be recognized and appreciate in value due
to a specific development with respect to that issuer. Developments creating a
special situation might include, among others, a new product or process, a
technological breakthrough, a management change or other extraordinary corporate
event, or differences in market supply of and demand for the security.
Investment in special situations may carry an additional risk of loss in the
event that the anticipated development does not occur or does not attract the
expected attention.
 
FOREIGN SECURITIES
   
Investments in foreign securities, including those of foreign governments, may
involve greater risks than investing in comparable domestic securities.
Securities of some foreign
    
 
   
 12   JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998
    
<PAGE>   
 
companies and governments may be traded in the United States, but most foreign
securities are traded primarily in foreign markets. The risks of foreign
investing include:
 
- - CURRENCY RISK. The Fund may buy the local currency when it buys a foreign
  currency denominated security and sell the local currency when it sells the
  security. As long as the Fund holds a foreign security, its value will be
  affected by the value of the local currency relative to the U.S. dollar. When
  the Fund sells a foreign denominated security, its value may be worth less in
  U.S. dollars even though the security increases in value in its home country.
  U.S. dollar denominated securities of foreign issuers may also be affected by
  currency risk.
 
- - POLITICAL AND ECONOMIC RISK. Foreign investments may be subject to heightened
  political and economic risks, particularly in underdeveloped or developing
  countries which may have relatively unstable governments and economies based
  on only a few industries. In some countries, there is the risk that the
  government may take over the assets or operations of a company or that the
  government may impose taxes or limits on the removal of the Fund's assets from
  that country. The Fund may invest in emerging market countries. Emerging
  market countries involve greater risks such as immature economic structures,
  national policies restricting investments by foreigners, and different legal
  systems.
 
- - REGULATORY RISK. There may be less government supervision of foreign markets.
  Foreign issuers may not be subject to the uniform accounting, auditing and
  financial reporting standards and practices applicable to domestic issuers.
  There may be less publicly available information about foreign issuers than
  domestic issuers.
 
- - MARKET RISK. Foreign securities markets, particularly those of underdeveloped
  or developing countries, may be less liquid and more volatile than domestic
  markets. Certain markets may require payment for securities before delivery
  and delays may be encountered in settling securities transactions. In some
  foreign markets, there may not be protection against failure by other parties
  to complete transactions. There may be limited legal recourse against an
  issuer in the event of a default on a debt instrument.
 
- - TRANSACTION COSTS. Transaction costs of buying and selling foreign securities,
  including brokerage, tax and custody costs, are generally higher than those
  involved in domestic transactions.
 
Foreign securities purchased indirectly (e.g., depositary receipts) are subject
to many of the above risks, including currency risk, because their values depend
on the performance of a foreign security denominated in its home currency.
 
FUTURES, OPTIONS AND OTHER DERIVATIVE INSTRUMENTS
The Fund may enter into futures contracts on securities, financial indices and
foreign currencies and options on such contracts ("futures contracts") and may
invest in options on securities, financial indices and foreign currencies
("options"), forward contracts and interest rate swaps and swap-related products
(collectively "derivative instruments"). The Fund intends to use most derivative
instruments primarily to hedge the value of its portfolio against potential
adverse movements in securities prices, foreign currency markets or interest
rates. To a limited extent, the Fund may also use derivative instruments for
nonhedging purposes such as seeking to increase the Fund's income or
 
   
JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998    13
    
<PAGE>   
 
otherwise seeking to enhance return. Please refer to Appendix A to this
Prospectus and the SAI for a more detailed discussion of these instruments.
 
The use of derivative instruments exposes the Fund to additional investment
risks and transaction costs. Risks inherent in the use of derivative instruments
include:
 
- - the risk that interest rates, securities prices and currency markets will not
  move in the direction that the portfolio managers anticipate;
 
- - imperfect correlation between the price of derivative instruments and
  movements in the prices of the securities, interest rates or currencies being
  hedged;
 
- - the fact that skills needed to use these strategies are different from those
  needed to select portfolio securities;
 
- - inability to close out certain hedged positions to avoid adverse tax
  consequences;
 
- - the possible absence of a liquid secondary market for any particular
  instrument and possible exchange-imposed price fluctuation limits, either of
  which may make it difficult or impossible to close out a position when
  desired;
 
- - leverage risk, that is, the risk that adverse price movements in an instrument
  can result in a loss substantially greater than the Fund's initial investment
  in that instrument (in some cases, the potential loss is unlimited); and
 
- - particularly in the case of privately negotiated instruments, the risk that
  the counterparty will fail to perform its obligations, which could leave the
  Fund worse off than if it had not entered into the position.
 
Although the Fund believes the use of derivative instruments will benefit the
Fund, the Fund's performance could be worse than if the Fund had not used such
instruments if the portfolio managers' judgement proves incorrect.
 
When the Fund invests in a derivative instrument, it may be required to
segregate cash and other liquid assets or certain portfolio securities with its
custodian to "cover" the Fund's position. Assets segregated or set aside
generally may not be disposed of so long as the Fund maintains the positions
requiring segregation or cover. Segregating assets could diminish the Fund's
return due to the opportunity losses of foregoing other potential investments
with the segregated assets.
 
HIGH-YIELD/HIGH-RISK SECURITIES
High-yield/high-risk securities (or "junk" bonds) are debt securities rated
below investment grade by the primary rating agencies such as Standard & Poor's
Ratings Services ("Standard & Poor's") and Moody's Investors Service, Inc.
("Moody's").
 
The value of lower quality securities generally is more dependent on the ability
of the company to meet interest and principal payments (i.e., credit risk) than
is the case for higher quality securities. Conversely, the value of higher
quality securities may be more sensitive to interest rate movements than lower
quality securities. In addition, companies issuing high-yield securities may be
more vulnerable to real or perceived economic changes, political changes or
other developments adverse to the company and lower quality securities may have
less liquid markets than higher quality securities. Investments
 
   
 14   JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998
    
<PAGE>   
 
in companies issuing high-yield securities are considered to be more speculative
than higher quality investments.
 
Issuers of high-yield securities are more vulnerable to real or perceived
economic changes (for instance, an economic downturn or prolonged period of
rising interest rates), political changes or adverse developments specific to
the issuer. The market for lower quality securities is generally less liquid
than the market for higher quality securities. Adverse publicity and investor
perceptions as well as new or proposed laws may also have a greater negative
impact on the market for lower quality securities.
 
Please refer to the SAI for a description of bond rating categories.
 
SHORT SALES
   
The Fund may engage in "short sales against the box." This technique involves
selling either a security that the Fund owns, or a security equivalent in kind
and amount to the security sold short that the Fund has the right to obtain, for
delivery at a specified date in the future. The Fund may enter into a short sale
against the box to hedge against anticipated declines in the market price of
portfolio securities. If the value of the securities sold short increases prior
to the scheduled delivery date, the Fund loses the opportunity to participate in
the gain.
    
 
See Appendix A for risks associated with certain other investments.
 
                               PERFORMANCE TERMS
 
This section will help you understand various terms that are commonly used to
describe the Fund's performance. You may see references to these terms in our
newsletters, advertisements and in media articles. Our newsletters and
advertisements may include comparisons of the Fund's performance to the
performance of other mutual funds, mutual fund averages or recognized stock
market indices. The Fund generally measures performance in terms of total
return.
 
CUMULATIVE TOTAL RETURN represents the actual rate of return on an investment
for a specified period. The Financial Highlights table shows total return for a
single fiscal period. Cumulative total return is generally quoted for more than
one year (e.g., the life of the Fund). A cumulative total return does not show
interim fluctuations in the value of an investment.
 
   
AVERAGE ANNUAL TOTAL RETURN represents the average annual percentage change of
an investment over a specified period. It is calculated by taking the cumulative
total return for the stated period and determining what constant annual return
would have produced the same cumulative return. Average annual returns for more
than one year tend to smooth out variations in the Fund's return and are not the
same as actual annual results.
    
 
THE FUND IMPOSES NO SALES OR OTHER CHARGES THAT WOULD AFFECT TOTAL RETURN
COMPUTATIONS. FUND PERFORMANCE FIGURES ARE BASED UPON HISTORICAL RESULTS AND ARE
NOT INTENDED TO INDICATE FUTURE PERFORMANCE. INVESTMENT RETURNS AND NET ASSET
VALUE WILL FLUCTUATE SO THAT AN INVESTOR'S SHARES, WHEN REDEEMED, MAY BE WORTH
MORE OR LESS THAN THEIR ORIGINAL COST.
 
   
JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998    15
    
<PAGE>   
 
                              SHAREHOLDER'S MANUAL
 
This section will help you become familiar with the different types of accounts
you can establish with Janus. This section also explains in detail the wide
array of services and features you can establish on your account. These services
and features may be modified or discontinued without shareholder approval or
prior notice.
 
Although the Fund has discontinued public sales of its shares to new investors,
shareholders who maintain open accounts will be able to continue to purchase
shares and reinvest any dividends and capital gains distributions in additional
shares. In addition, the Fund will continue to accept new accounts which are
opened under taxpayer identification numbers that are identical to those for
existing Fund accounts.
 
   
Once a Fund account is closed, it may not be reopened. An account may be
considered closed and subject to redemption by the Fund in the circumstances
discussed under "Involuntary Redemptions" on page 25.
    
 
   
    MINIMUM INVESTMENTS*
    
 
   
<TABLE>
      <S>                                                  <C>
      To open a new account..............................   $2,500
      To open a new retirement, education or UGMA/UTMA
        account..........................................   $  500
      To open a new account with an Automatic Investment
        Program..........................................   $  500**
      To add to any type of an account...................   $  100+
</TABLE>
    
 
   
     * THE FUND RESERVES THE RIGHT TO CHANGE THE AMOUNT OF THESE MINIMUMS
       FROM TIME TO TIME OR TO WAIVE THEM IN WHOLE OR IN PART FOR CERTAIN
       TYPES OF ACCOUNTS.
    
   
    ** AN AUTOMATIC INVESTMENT PROGRAM REQUIRES A $100 MINIMUM AUTOMATIC
       INVESTMENT PER MONTH UNTIL THE ACCOUNT BALANCE REACHES $2,500.
    
   
     + THE MINIMUM SUBSEQUENT INVESTMENT FOR IRA UGMA/UTMA ACCOUNTS IS $50.
    
 
HOW TO GET IN TOUCH WITH JANUS
   
If you have any questions while reading this Prospectus, please call one of our
Investor Service Representatives at 1-800-525-3713 Monday-Friday: 8:00 a.m.-8:00
p.m., and Saturday: 10:00 a.m.-4:00 p.m., New York time. The Quick Address and
Telephone Reference below includes other ways to get in touch with Janus.
    
 
   
   QUICK ADDRESS AND TELEPHONE REFERENCE
    
 
   
<TABLE>
    <S>                                     <C>
    MAILING ADDRESS                         JANUS XPRESS
    Janus                                   LINE(TM)     1-888-979-7737
    P.O. Box 173375                         For 24-hour access to account and
    Denver, CO 80217-3375                   fund information, exchanges and
                                            purchases, automated daily quotes
    FOR OVERNIGHT CARRIER                   on fund share prices, yields and
    Janus                                   total refunds.
    Suite 101
    3773 Cherry Creek North Drive           TDD                  1-800-525-0056
    Denver, CO 80209-3811                   A telecommunications device for
                                            our hearing- and speech-impaired
    JANUS INTERNET ADDRESS                  shareholders.
    http://www.Janus.com
                                            JANUS LITERATURE
                                            LINE    1-800-525-8983
                                            To request a prospectus,
                                            shareholder reports or marketing
                                            materials.
</TABLE>
    
 
   
 16   JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998
    
<PAGE>   
 
TYPES OF ACCOUNT OWNERSHIP
   
As discussed above, the Fund will accept new accounts opened under taxpayer
identification numbers identical to those on current Fund accounts. You can
establish the following types of accounts by completing a New Account
Application. To request an application, call 1-800-525-3713.
    
 
- - INDIVIDUAL OR JOINT OWNERSHIP. Individual accounts are owned by one person.
  Joint accounts have two or more owners.
 
- - A GIFT OR TRANSFER TO MINOR (UGMA OR UTMA). An UGMA/ UTMA account is a
  custodial account managed for the benefit of a minor. To open an UGMA or UTMA
  account, you must include the minor's Social Security number on the
  application.
 
- - TRUST. An established trust can open an account. The names of each trustee,
  the name of the trust and the date of the trust agreement must be included on
  the application.
 
   
- - BUSINESS ACCOUNTS. Corporations and partnerships may also open an account. The
  application must be signed by an authorized officer of the corporation or a
  general partner of the partnership.
    
 
   
TAX-DEFERRED ACCOUNTS
    
   
If you are eligible, you may set up one or more tax-deferred accounts. A
tax-deferred account allows you to shelter your investment income and capital
gains from current income taxes. A contribution to certain of these plans may
also be tax deductible. Tax-deferred accounts include retirement plans and the
Education IRA. Distributions from these plans are generally subject to income
tax and may be subject to an additional tax if withdrawn prior to age 59 1/2 or
used for a nonqualifying purpose. Investors should consult their tax advisor or
legal counsel before selecting a tax-deferred account.
    
 
   
Investors Fiduciary Trust Company serves as custodian for the tax-deferred
accounts offered by the Fund. There is an annual $12 fee per account to maintain
your tax-deferred account. The maximum annual fee is $24 per taxpayer
identification number. You may pay the fee by check or have it automatically
deducted from your account (usually in December). The Fund reserves the right to
change the amount of this fee or to waive it in whole or in part for certain
types of accounts.
    
 
   
The following plans require a special application. For an application and more
details about our Retirement Plans, call 1-800-525-3713.
    
 
   
- - REGULAR AND ROTH INDIVIDUAL RETIREMENT ACCOUNTS ("IRAS"): Both types of IRAs
  allow most individuals with earned income to contribute up to the lesser of
  $2,000 ($4,000 for most married couples) or 100% of compensation annually.
  Please refer to the Janus IRA booklet for complete information regarding the
  different types of IRAs.
    
 
   
- - EDUCATION IRA: This plan allows individuals, subject to certain income
  limitations, to contribute up to $500 annually on behalf of any child under
  the age of 18. Please refer to the Janus IRA booklet for complete information
  regarding the Education IRA.
    
 
   
JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998    17
    
<PAGE>   
 
   
- - SIMPLIFIED EMPLOYEE PENSION PLAN ("SEP"): This plan allows small business
  owners (including sole proprietors) to make tax-deductible contributions for
  themselves and any eligible employee(s). A SEP requires an IRA (a SEP-IRA) to
  be set up for each SEP participant.
    
 
- - PROFIT SHARING OR MONEY PURCHASE PENSION PLAN: These plans are open to
  corporations, partnerships and sole proprietors to benefit their employees and
  themselves.
 
   
- - SECTION 403(B)(7) PLAN: Employees of educational organizations or other
  qualifying, tax-exempt organizations may be eligible to participate in a
  Section 403(b)(7) Plan.
    
 
HOW TO OPEN YOUR JANUS ACCOUNT
   
If you are a current Fund shareholder and want to open another Fund account,
complete and sign the appropriate application. Please be sure to provide your
Social Security or taxpayer identification number on the application and make
your check payable to Janus. The Fund is available only to U.S. citizens or
residents, and your application will be returned to you if you do not meet these
criteria. Send all items to one of following addresses:
    
 
   
For Overnight Carrier
    
   
- --------------------
    
Janus
 
Suite 101
3773 Cherry Creek North Drive
Denver, CO 80209-3811
 
   
For All Other Inquiries
    
   
- ---------------------
    
   
Janus
    
 
   
P.O. Box 173375
    
   
Denver, CO 80217-3375
    
 
INVESTOR SERVICE CENTERS
   
Janus offers two Investor Service Centers for those individuals who would like
to conduct their investing in person. Our representatives will be happy to
assist you at either of the following locations: Monday-Friday 7:00 a.m. to 6:00
p.m. Mountain time and Saturday 9:00 a.m. to 1:00 p.m. Mountain time.
    
 
100 Fillmore Street, Suite 100
Denver, CO 80206
 
3773 Cherry Creek North Drive, Suite 101
Denver, CO 80209
 
HOW TO PURCHASE SHARES
PAYING FOR SHARES
When you purchase shares, your request will be processed at the next NAV
calculated after your order is received and accepted. Please note the following:
 
- - Cash, credit cards, third party checks and credit card checks will not be
  accepted.
 
   
 18   JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998
    
<PAGE>   
 
- - All purchases must be made in U.S. dollars.
 
- - Checks must be drawn on a U.S. bank and made payable to Janus.
 
- - If a check does not clear your bank, the Fund reserves the right to cancel the
  purchase.
 
- - If the Fund is unable to debit your predesignated bank account on the day of
  purchase, it may make additional attempts or cancel the purchase.
 
- - The Fund reserves the right to reject any specific purchase request.
 
If your purchase is cancelled you will be responsible for any losses or fees
imposed by your bank and losses that may be incurred as a result of any decline
in the value of the cancelled purchase. The Fund (or its agents) has the
authority to redeem shares in your account(s) to cover any such losses due to
fluctuations in share price. Any profit on such cancellation will accrue to the
Fund.
 
   
ONCE YOU HAVE OPENED YOUR JANUS ACCOUNT, THE MINIMUM AMOUNT FOR AN ADDITIONAL
INVESTMENT IS $100 ($50 FOR IRAS OR UGMA/UTMA ACCOUNTS). You may add to your
account at any time through any of the following options:
    
 
BY MAIL
Complete the remittance slip attached at the bottom of your confirmation
statement. If you are making a purchase into a retirement account, please
indicate whether the purchase is a rollover or a current or prior year
contribution. Send your check and remittance slip or written instructions to one
of the addresses listed previously. You may also request a booklet of remittance
slips for non-retirement accounts.
 
BY TELEPHONE
   
This service allows you to purchase additional shares quickly and conveniently
through an electronic transfer of money. To purchase shares by telephone, call
an Investor Service Representative at 1-800-525-3713 during normal business
hours or call the Janus Xpress Line, 1-888-979-7737, for access to this option
24 hours a day. When you make an additional purchase by telephone, Janus will
automatically debit your predesignated bank account for the desired amount. To
establish the telephone purchase option on your new account, complete the
"Telephone Purchase of Shares Option" section on the application and attach a
"voided" check or deposit slip from your bank account. If your account is
already established, call 1-800-525-3713 to request the appropriate form. This
option will become effective ten business days after the form is received.
    
 
BY WIRE
Purchases may also be made by wiring money from your bank account to your Janus
account. Call 1-800-525-3713 to receive wiring instructions.
 
AUTOMATIC INVESTMENT PROGRAMS
   
Janus offers several automatic investment programs to help you achieve your
financial goals as simply and conveniently as possible. You may open a new
account with a $500 initial purchase and $100 automatic subsequent investments.
    
 
   
JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998    19
    
<PAGE>   
 
   
- - AUTOMATIC MONTHLY INVESTMENT PROGRAM
    
  You select the day each month that your money ($100 minimum) will be
  electronically transferred from your bank account to your Fund account. To
  establish this option, complete the "Automatic Monthly Investment Program"
  section on the application and attach a "voided" check or deposit slip from
  your bank account. If your Fund account is already established, call
  1-800-525-3713 to request the appropriate form.
 
- - PAYROLL DEDUCTION
   
  If your employer can initiate an automatic payroll deduction, you may have all
  or a portion of your paycheck ($100 minimum) invested directly into your Fund
  account. To obtain information on establishing this option, call
  1-800-525-3713.
    
 
- - SYSTEMATIC EXCHANGE
  With a Systematic Exchange you determine the amount of money ($100 minimum)
  you would like automatically exchanged from one Janus account to another on
  any day of the month. For more information on how to establish this option,
  call 1-800-525-3713.
 
HOW TO EXCHANGE SHARES
On any business day, you may exchange all or a portion of your shares into any
other available Janus fund.
 
IN WRITING
   
To request an exchange in writing, please follow the instructions for written
requests on page 22.
    
 
BY TELEPHONE
   
All accounts are automatically eligible for the telephone exchange option. To
exchange shares by telephone, call an Investor Service Representative at
1-800-525-3713 during normal business hours or call the Janus Xpress Line,
1-888-979-7737, for access to this option 24 hours a day.
    
 
BY SYSTEMATIC EXCHANGE
   
As noted above, you may establish a Systematic Exchange for as little as $100
per month on established accounts. You may establish a new account with a $500
initial purchase and subsequent $100 systematic exchanges. If the balance in the
account you are exchanging from falls below the systematic exchange amount, all
remaining shares will be exchanged and the program will be discontinued.
    
 
EXCHANGE POLICIES
- - Except for Systematic Exchanges, new accounts established by exchange must be
  opened with $2,500 or the total account value if the value of the account you
  are exchanging from is less than $2,500.
 
- - Exchanges between existing accounts must meet the $100 subsequent investment
  requirement.
 
- - You may make four exchanges out of the Fund during a calendar year (exclusive
  of Systematic Exchanges) free of charge.
 
- - Exchanges between accounts will be accepted only if the registrations are
  identical.
 
   
 20   JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998
    
<PAGE>   
 
- - If the shares you are exchanging are held in certificate form, you must return
  the certificate to the Fund prior to making any exchanges.
 
- - Be sure to read the prospectus for the fund into which you are exchanging.
 
- - The Fund reserves the right to reject any exchange request and to modify or
  terminate the exchange privilege at any time. For example, the Fund may reject
  exchanges from accounts engaged in excessive trading (including market timing
  transactions) that are believed to be detrimental to the Fund.
 
- - An exchange represents the sale of shares from one fund and the purchase of
  shares of another fund, which may produce a taxable gain or loss in a non-tax
  deferred account.
 
   
HOW TO REDEEM SHARES
    
On any business day, you may redeem all or a portion of your shares. REMEMBER
THAT THE FUND IS CLOSED TO NEW INVESTORS AND IF A TOTAL REDEMPTION IS MADE
ADDITIONAL INVESTMENTS IN YOUR FUND ACCOUNT MIGHT NOT BE POSSIBLE.
 
If the shares are held in certificate form, the certificate must be returned
with or before your redemption request. Your transaction will be processed at
the next NAV calculated after your order is received and accepted.
 
IN WRITING
   
To request a redemption in writing, please follow the instructions for written
requests noted on page 22.
    
 
BY TELEPHONE
   
Most accounts have the telephone redemption option, unless this option was
specifically declined on the application or in writing. This option enables you
to request redemptions daily from your account by calling 1-800-525-3713 by the
close of the regular trading session of the New York Stock Exchange ("NYSE")
normally 4:00 p.m. New York time. You may also use Janus Xpress Line,
1-888-979-7737, for access to this option 24 hours a day. Redemption requests
received through Janus Xpress Line will be processed at the NAV next calculated
after receipt and acceptance of the request. (There is a daily limit of $100,000
per account for redemptions payable by check.)
    
 
SYSTEMATIC REDEMPTION OPTION
Systematic Redemption Options allow you to redeem a specific dollar amount from
your Fund account on a regular basis. For more information or to request the
appropriate form, please call 1-800-525-3713.
 
PAYMENT OF REDEMPTION PROCEEDS
- - BY CHECK
  Redemption proceeds will be sent to the shareholder(s) of record at the
  address of record within seven days after receipt of a valid redemption
  request.
 
   
- - BY ELECTRONIC TRANSFER
    
   
  If you have established the electronic redemption option, your redemption
  proceeds can be electronically transferred to your predesignated bank account
  on the next bank business day after receipt of your redemption request (wire
  transfer) or the second
    
 
   
JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998    21
    
<PAGE>   
 
   
  bank business day after receipt of your redemption request (ACH transfer).
  Wire transfers will be charged an $8 fee per wire and your bank may charge an
  additional fee to receive the wire. ACH transfers are made free of charge.
  Wire redemptions are not available for retirement accounts.
    
 
   
  If you would like to establish the electronic redemption option on an existing
  account, please call 1-800-525-3713 to request the appropriate form.
    
 
   
IF THE SHARES BEING REDEEMED WERE PURCHASED BY CHECK, TELEPHONE OR THROUGH THE
AUTOMATIC MONTHLY INVESTMENT PROGRAM, THE FUND MAY DELAY THE PAYMENT OF YOUR
REDEMPTION PROCEEDS FOR UP TO 15 DAYS FROM THE DAY OF PURCHASE TO ALLOW THE
PURCHASE TO CLEAR. Unless you provide alternate instructions, your proceeds will
be invested in Janus Money Market Fund - Investor Shares during the 15 day hold
period.
    
 
WRITTEN INSTRUCTIONS
   
To redeem all or part of your shares in writing, your request should be sent to
one of the addresses listed on page 18 and must include the following
information:
    
 
- - the name of the Fund
 
- - the account number
 
- - the amount of money or number of shares being redeemed
 
- - the name(s) on the account registration
 
- - the signature(s) of all registered account owners
 
- - your daytime telephone number
 
SIGNATURE REQUIREMENTS BASED ON ACCOUNT TYPE
   
- - Individual, Joint Tenants, Tenants in Common: Written instructions must be
 --------------------------------------------
    
   
signed by each shareholder, exactly as the names appear in the account
 registration.
    
 
   
- - UGMA or UTMA: Written instructions must be signed by the custodian in
 ------------------
    
   
his/her capacity as it appears in the account registration.
    
 
   
- - Sole Proprietor, General Partner: Written instructions must be signed by an
 --------------------------------
    
   
authorized individual in his/her capacity as it appears on the account
 registration.
    
 
   
- - Corporation, Association: Written instructions must be signed by the
 ------------------------
    
   
person(s) authorized to act on the account. In addition, a certified copy of the
 corporate resolution authorizing the signer to act must accompany the request.
    
 
   
- - Trust: Written instructions must be signed by the trustee(s). If the name(s)
of
 ------
    
   
the current trustee(s) does not appear in the account registration, a
certificate of incumbency dated within 60 days must also be submitted.
    
 
   
- - IRA: Written instructions must be signed by the account owner. If you do
 -----
    
   
not want federal income tax withheld from your redemption, you must state that
you elect not to have such withholding apply. In addition, your instructions
 must state
    
 
   
 22   JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998
    
<PAGE>   
 
   
whether the distribution is normal (after age 59 1/2) or premature (before age
59 1/2) and, if premature, whether any exceptions such as death or disability
apply with regard to the 10% additional tax on early distributions.
    
 
   
SIGNATURE GUARANTEE
    
In addition to the signature requirements, A SIGNATURE GUARANTEE IS ALSO
REQUIRED if any of the following is applicable:
 
   
- - You request a redemption that exceeds $100,000.
    
 
- - You would like the check made payable to anyone other than the shareholder(s)
  of record.
 
- - You would like the check mailed to an address which has been changed within 10
  days of the redemption request.
 
- - You would like the check mailed to an address other than the address of
  record.
 
THE FUNDS RESERVE THE RIGHT TO REQUIRE A SIGNATURE GUARANTEE UNDER OTHER
CIRCUMSTANCES OR TO REJECT OR DELAY A REDEMPTION ON CERTAIN LEGAL GROUNDS. FOR
MORE INFORMATION PERTAINING TO SIGNATURE GUARANTEES, PLEASE CALL 1-800-525-3713.
 
HOW TO OBTAIN A SIGNATURE GUARANTEE
   
A signature guarantee assures that a signature is genuine. The signature
guarantee protects shareholders from unauthorized account transfers. The
following financial institutions may guarantee signatures: banks, savings and
loan associations, trust companies, credit unions, broker-dealers, and member
firms of a national securities exchange. Call your financial institution to see
if they have the ability to guarantee a signature. A signature guarantee may not
be provided by a notary public.
    
 
If you live outside the United States, a foreign bank properly authorized to do
business in your country of residence or a U.S. consulate may be able to
authenticate your signature.
 
   
PRICING OF FUND SHARES
    
   
All purchases, redemptions and exchanges will be processed at the NAV next
calculated after your request is received and approved by the Fund (or its
designated agent). The Fund's NAV is calculated at the close of the regular
trading session of the NYSE (normally 4:00 p.m. New York time) each day that the
NYSE is open. In order to receive a day's price, your order must be received by
the close of the regular trading session of the NYSE. Securities are valued at
market value or, if a market quotation is not readily available, at their fair
value determined in good faith under procedures established by and under the
supervision of the Trustees. Short-term instruments maturing within 60 days are
valued at amortized cost, which approximates market value. See the SAI for more
detailed information.
    
 
SHAREHOLDER SERVICES AND ACCOUNT POLICIES
   
JANUS XPRESS LINE(TM)
    
   
Janus Xpress Line, our electronic telephone service, offers you 24-hour access
by TouchTone(TM) telephone to obtain information on account balances, Fund
performance or
    
 
   
JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998    23
    
<PAGE>   
 
   
dividends. You can also make exchanges, purchases, redemptions and electronic
transfers in existing accounts, request literature about any Janus fund, or
order duplicate statements. Janus Xpress Line is accessed by calling
1-888-979-7737. Calls are limited to five minutes.
    
 
JANUS WEB SITE
   
Janus maintains a Web site located at http://www.Janus.com. You can access
information such as your account balance and the Fund's NAV through the Web
site. In addition, you may request and/or download a prospectus for any Janus
fund.
    
 
ACCOUNT MINIMUMS
   
Minimum account sizes are noted on page 16. An account established on or before
February 18, 1996 is required to meet the minimum balances in effect when the
account was established ($1,000 for regular accounts and $250 for retirement and
UGMA/UTMA accounts). An active Automatic Monthly Investment (AMI) on any such
account exempted it from any minimum initial investment requirement and
continues to do so. In addition, an active AMI on these accounts may continue at
$50 per month, provided there is no interruption in the AMI program. All other
subsequent investments must meet the $100 required minimum.
    
 
   
Due to the proportionately higher costs of maintaining small accounts, Janus
reserves the right to deduct a $10 minimum balance fee (or the value of the
account if less than $10) from accounts with values below the minimums described
on page 16 or to close such accounts. This policy will apply to accounts
participating in the Automatic Monthly Investment Program only if your account
balance does not reach the required minimum initial investment or falls below
such minimum and you have discontinued monthly investments. This policy does not
apply to accounts that fall below the minimums solely as a result of market
value fluctuations. It is expected that, for purposes of this policy, accounts
will be valued in September, and the $10 fee will be assessed on the second
Friday of September of each year. You will receive notice before we charge the
$10 fee or close your account so that you may increase your account balance to
the required minimum.
    
 
TRANSACTIONS THROUGH PROCESSING ORGANIZATIONS
You may purchase or sell Fund shares through a broker-dealer, bank or other
financial institution, or an organization that provides recordkeeping and
consulting services to 401(k) plans or other employee benefit plans (a
"Processing Organization"). Processing Organizations may charge you a fee for
this service and may require different minimum initial and subsequent
investments than the Fund. Processing Organizations may also impose other
charges or restrictions different from those applicable to shareholders who
invest in the Fund directly. A Processing Organization, rather than its
customer, may be the shareholder of record of your shares. The Fund is not
responsible for the failure of any Processing Organization to carry out its
obligations to its customers. Certain Processing Organizations may receive
compensation from Janus Capital or its affiliates and certain Processing
Organizations may receive compensation from the Fund for shareholder
recordkeeping and similar services.
 
   
 24   JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998
    
<PAGE>   
 
TAXPAYER IDENTIFICATION NUMBER
On your application or other appropriate form, you will be asked to certify that
your Social Security or taxpayer identification number is correct and that you
are not subject to backup withholding for failing to report income to the IRS.
If you are subject to the 31% backup withholding or you did not certify your
taxpayer identification, the IRS requires the Fund to withhold 31% of any
dividends paid and redemption or exchange proceeds. In addition to the 31%
backup withholding, you may be subject to a $50 fee to reimburse the Fund for
any penalty that the IRS may impose.
 
SHARE CERTIFICATES
Most shareholders choose not to hold their shares in certificate form because
account transactions such as exchanges and redemptions cannot be completed until
the certificate has been returned to the Fund. The Fund will issue share
certificates upon written request only. Share certificates will not be issued
until the shares have been held for at least 15 days and will not be issued for
accounts that do not meet the minimum investment requirements. Share
certificates cannot be issued for retirement accounts. In addition, if the
certificate is lost, there may be a replacement charge.
 
INVOLUNTARY REDEMPTIONS
The Fund reserves the right to close an account if the shareholder is deemed to
engage in activities which are illegal or otherwise believed to be detrimental
to the Fund.
 
TELEPHONE TRANSACTIONS
You may initiate many transactions by telephone. The Fund and its agents will
not be responsible for any losses resulting from unauthorized transactions when
procedures designed to verify the identity of the caller are followed.
 
   
It may be difficult to reach an Investor Service Representative by telephone
during periods of unusual market activity. If you are unable to reach a
representative by telephone, please consider sending written instructions,
stopping by a Service Center, or in the case of purchases, exchanges,
redemptions and electronic transfers, calling the Janus Xpress Line.
    
 
TEMPORARY SUSPENSION OF SERVICES
The Fund or its agents may, in case of emergency, temporarily suspend telephone
transactions or other shareholder services.
 
ADDRESS CHANGES
To change the address on your account, call 1-800-525-3713 or send a written
request signed by all account owners. Include the name of the Fund, the account
number(s), the name(s) on the account and both the old and new addresses.
Certain options may be suspended for 10 days following an address change unless
a signature guarantee is provided.
 
REGISTRATION CHANGES
To change the name on an account, the shares are generally transferred to a new
account. In some cases, legal documentation may be required. For more
information call 1-800-525-3713.
 
   
JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998    25
    
<PAGE>   
 
STATEMENTS AND REPORTS
   
Investors participating in an automatic investment program will receive
quarterly confirmations of all transactions. (Dividend information will be
distributed annually.) In addition, the Fund will send you an immediate
transaction confirmation statement after every non-systematic transaction.
    
 
Financial reports for the Fund, which include a list of the Fund's portfolio
holdings, will be mailed semiannually to all shareholders. To reduce expenses,
only one copy of most financial reports will be mailed to accounts with the same
record address. Upon request, such reports will be mailed to all accounts in the
same household. Please call 1-800-525-3713 if you would like to receive
additional reports.
 
   
 26   JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998
    
<PAGE>   
 
                             MANAGEMENT OF THE FUND
 
TRUSTEES
The Trustees oversee the business affairs of the Trust and are responsible for
major decisions relating to the Fund's investment objective and policies. The
Trustees delegate the day-to-day management of the Fund to the officers of the
Trust and meet at least quarterly to review the Fund's investment policies,
performance, expenses and other business affairs.
 
INVESTMENT ADVISER
Janus Capital, 100 Fillmore Street, Denver, Colorado 80206-4928, is the
investment adviser to the Fund and is responsible for the day-to-day management
of its investment portfolio and other business affairs.
 
Janus Capital began serving as investment adviser to certain series of the Trust
in 1970 and currently serves as investment adviser to all of the Janus funds, as
well as adviser or subadviser to other mutual funds and individual, corporate,
charitable and retirement accounts.
 
Kansas City Southern Industries, Inc. ("KCSI") owns approximately 83% of the
outstanding voting stock of Janus Capital, most of which it acquired in 1984.
KCSI is a publicly traded holding company whose primary subsidiaries are engaged
in transportation, information processing and financial services. Thomas H.
Bailey, President and Chairman of the Board of Janus Capital, owns approximately
12% of its voting stock and, by agreement with KCSI, selects a majority of Janus
Capital's Board.
 
Janus Capital furnishes continuous advice and recommendations concerning the
Fund's investments. Janus Capital also furnishes certain administrative,
compliance and accounting services for the Fund, and may be reimbursed by the
Fund for its costs in providing those services. In addition, Janus Capital
employees serve as officers of the Trust and Janus Capital provides office space
for the Fund and pays the salaries, fees and expenses of all Fund officers and
those Trustees who are affiliated with Janus Capital.
 
PORTFOLIO MANAGERS
   
The Fund is managed by a management team consisting of James P. Craig, William
Bales and Jonathan Coleman, each of whom also serves as Executive Vice President
of the Fund. The management team began managing the Fund on February 1, 1997.
The portfolio managers' other primary responsibilities and education are set
forth below.
    
 
JAMES P. CRAIG, III is Chief Investment Officer of Janus Capital. He is
Executive Vice President and portfolio manager of Janus Fund, which he has
managed since 1986. Mr. Craig previously managed the Fund from its inception to
December 1993 and Janus Balanced Fund from December 1993 to December 1995. He
holds a Bachelor of Arts in Business from the University of Alabama and a Master
of Arts in Finance from the Wharton School of the University of Pennsylvania.
 
   
WILLIAM H. BALES has been a research analyst with Janus Capital since 1993,
focusing primarily on the transportation, consumer products and restaurant
industries. He began
    
 
   
JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998    27
    
<PAGE>   
 
   
his career at Janus in September 1991 as an Investor Service Representative. Mr.
Bales holds a Bachelor of Science in Marketing and a Master of Science in
Marketing and Finance from the University of Colorado. He is seeking the
Chartered Financial Analyst designation.
    
 
   
JONATHAN D. COLEMAN has been a research analyst with Janus Capital since July
1994, focusing primarily on the railroad, computer, healthcare and financial
services industries. Prior to joining Janus, Mr. Coleman was a Fulbright Fellow
from August 1993 until June 1994. He holds a Bachelor of Arts in Political
Economy and Spanish from Williams College (1991-1993) and is seeking the
Chartered Financial Analyst designation.
    
 
   
PERSONAL INVESTING
    
   
Janus Capital does not permit portfolio managers to purchase and sell securities
for their own accounts, except under the limited exceptions contained in Janus
Capital's policy governing personal investing. Janus Capital's policy requires
investment and other personnel to conduct their personal investment activities
in a manner that Janus Capital believes is not detrimental to the Fund or Janus
Capital's other advisory clients. See the SAI for more detailed information.
    
 
BREAKDOWN OF MANAGEMENT EXPENSES
   
The Fund pays Janus Capital a management fee which is calculated daily and paid
monthly. The advisory agreement with the Fund spells out the management fee and
other expenses that the Fund must pay. The Fund is subject to the following
management fee schedule (expressed as an annual rate):
    
 
   
<TABLE>
<CAPTION>
    AVERAGE DAILY NET ASSETS OF FUND            ANNUAL RATE PERCENTAGE (%)
    <S>                                         <C>
</TABLE>
    
 
   
- --------------------------------------------------------------------------------
    
 
   
<TABLE>
    <S>                                        <C>
    First $300 Million                                    0.75
    Next $200 Million                                     0.70
    Over $500 Million                                     0.65
</TABLE>
    
 
- --------------------------------------------------------------------------------
 
   
The actual management fee paid by the Fund for the fiscal year ended October 31,
1997 was 0.68% of the value of the Fund's average daily net assets. The Fund
incurs expenses not assumed by Janus Capital, including transfer agent and
custodian fees and expenses, legal and auditing fees, printing and mailing costs
of sending reports and other information to existing shareholders, and
independent Trustees' fees and expenses.
    
 
   
PORTFOLIO TRANSACTIONS
    
   
Purchases and sales of securities on behalf of the Fund are executed by
broker-dealers selected by Janus Capital. Broker-dealers are selected on the
basis of their ability to obtain best price and execution for the Fund's
transactions and recognizing brokerage, research and other services provided to
the Fund and to Janus Capital. Janus Capital may also consider payments made by
brokers effecting transactions for the Fund i) to the Fund or ii) to other
persons on behalf of the Fund for services provided to the Fund for which it
would be obligated to pay. Janus Capital may also consider sales of shares of a
Janus fund as a factor in the selection of broker-dealers to execute
transactions. The Fund's Trustees have authorized Janus Capital to place
portfolio transactions on an agency basis with a broker-dealer affiliated with
Janus Capital. When transactions for the
    
 
   
 28   JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998
    
<PAGE>   
 
Fund are effected with that broker-dealer, the commissions payable by the Fund
are credited against certain Fund operating expenses serving to reduce those
expenses. The SAI further explains the selection of broker-dealers.
 
OTHER SERVICE PROVIDERS
The following parties provide the Fund with administrative and other services.
 
CUSTODIAN
State Street Bank and Trust Company
P.O. Box 0351
Boston, Massachusetts 02117-0351
 
TRANSFER AGENT
Janus Service Corporation
P.O. Box 173375
Denver, Colorado 80217-3375
 
DISTRIBUTOR
Janus Distributors, Inc.
100 Fillmore Street
Denver, Colorado 80206-4928
 
Janus Service Corporation and Janus Distributors, Inc. are wholly-owned
subsidiaries of Janus Capital.
 
OTHER INFORMATION
ORGANIZATION
The Trust is a "mutual fund" that was organized as a Massachusetts business
trust on February 11, 1986. A mutual fund is an investment vehicle that pools
money from numerous investors and invests the money to achieve a specified
objective.
 
   
As of the date of this Prospectus, the Trust offers 19 separate series, three of
which currently offer three classes of shares. The Fund became a series of the
Trust on August 7, 1992. It was previously known as Janus Venture Fund, Inc., a
Maryland corporation. All references in this Prospectus to the Fund prior to the
above date are to its predecessor entity and all references after such date are
to the series of the Trust.
    
 
   
The Trust currently offers the other 18 series by other prospectuses.
    
 
SHAREHOLDER MEETINGS
   
The Trust does not intend to hold annual shareholder meetings. However, special
meetings may be called specifically for the Fund or for the Trust as a whole for
purposes such as electing or removing Trustees, terminating or reorganizing the
Trust, changing fundamental policies, or for any other purpose requiring a
shareholder vote under the 1940 Act. Separate votes are taken by the Fund only
if a matter affects or requires the vote of just the Fund or the Fund's interest
in the matter differs from the interest of other portfolios of the Trust. As a
shareholder, you are entitled to one vote for each share that you own.
    
 
   
JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998    29
    
<PAGE>   
 
SIZE OF THE FUND
The Fund has discontinued sales of its shares because its management believes
that a substantial increase in size may adversely affect the Fund's ability to
achieve its investment objective by reducing its flexibility in making
investments and in effecting portfolio changes. Although sales to new investors
have been discontinued, existing shareholders are permitted to continue to
purchase shares and to reinvest any dividends or capital gains distributions.
See the Shareholder's Manual beginning on page 16.
 
MASTER/FEEDER OPTION
   
The Trust may in the future seek to achieve the Fund's investment objective by
investing all of the Fund's assets in another investment company having the same
investment objective and substantially the same investment policies and
restrictions as those applicable to the Fund. Unless otherwise required by law,
this policy may be implemented by the Trustees without shareholder approval.
    
 
   
YEAR 2000
    
   
Many computer systems use six-digit fields to store dates. With the approach of
the year 2000, these fields must be converted to eight-digit fields in order to
recognize the difference between 1900 and 2000. Failure to adequately address
this issue could have potentially serious repercussions. Preparing for Year 2000
is a high priority for Janus Capital, which has established a dedicated group to
address this issue and has entered into a consulting arrangement with one of the
foremost experts in Year 2000 compliance to assess systems implications for
Janus Capital. Janus Capital does not anticipate that the move to Year 2000 will
have a material impact on its ability to continue to provide the Fund with
service at current levels.
    
 
   
 30   JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998
    
<PAGE>   
 
   
                            DISTRIBUTIONS AND TAXES
    
 
DISTRIBUTIONS
   
TO AVOID TAXATION, THE INTERNAL REVENUE CODE REQUIRES THE FUND TO DISTRIBUTE NET
INCOME AND ANY NET CAPITAL GAINS REALIZED BY ITS INVESTMENTS ANNUALLY. THE
FUND'S INCOME FROM DIVIDENDS AND INTEREST AND ANY NET REALIZED SHORT-TERM
CAPITAL GAINS ARE PAID TO SHAREHOLDERS AS ORDINARY INCOME DIVIDENDS. NET
REALIZED LONG-TERM GAINS ARE PAID TO SHAREHOLDERS AS CAPITAL GAINS
DISTRIBUTIONS.
    
 
HOW DISTRIBUTIONS AFFECT THE FUND'S NAV
Distributions are paid to shareholders as of the record date of the distribution
of the Fund, regardless of how long the shares have been held. Dividends and
capital gains awaiting distribution are included in the Fund's daily NAV. The
share price of the Fund drops by the amount of the distribution, net of any
subsequent market fluctuations. As an example, assume that on December 31, the
Fund declared a dividend in the amount of $0.25 per share. If the Fund's share
price was $10.00 on December 30, the Fund's share price on December 31 would be
$9.75, barring market fluctuations. Shareholders should be aware that
distributions from a taxable mutual fund are not value-enhancing and may create
income tax obligations.
 
"BUYING A DIVIDEND"
If you purchase shares of the Fund just before the distribution, you will pay
the full price for the shares and receive a portion of the purchase price back
as a taxable distribution. This is referred to as "buying a dividend." In the
above example, if you bought shares on December 30, you would have paid $10.00
per share. On December 31, the Fund would pay you $0.25 per share as a dividend
and your shares would now be worth $9.75 per share. Unless your account is set
up as a tax-deferred account, dividends paid to you would be included in your
gross income for tax purposes, even though you may not have participated in the
increase in NAV of the Fund, whether or not you reinvested the dividends.
 
DISTRIBUTION OPTIONS
   
When you open an account, you must specify on your application how you want to
receive your distributions. You may change your distribution option at any time
by writing the Fund at one of the addresses on page 18 or calling
1-800-525-3713. The Fund offers the following options:
    
 
1. REINVESTMENT OPTION. You may reinvest your income dividends and capital gains
   distributions in additional shares. This option is assigned automatically if
   no other choice is made.
 
2. CASH OPTION. You may receive your income dividends and capital gains
   distributions in cash.
 
3. REINVEST AND CASH OPTION. You may receive either your income dividends or
   capital gains distributions in cash and reinvest the other in additional
   shares.
 
   
JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998    31
    
<PAGE>   
 
4. REDIRECT OPTION. You may direct your dividends or capital gains to purchase
   shares of another Janus fund.
 
The Fund reserves the right to reinvest into your account undeliverable and
uncashed dividend and distribution checks that remain outstanding for six months
in shares of the Fund at the NAV next computed after the check is cancelled.
Subsequent distributions may also be reinvested.
 
TAXES
   
As with any investment, you should consider the tax consequences of investing in
the Fund. The following discussion does not apply to tax-deferred accounts, nor
is it a complete analysis of the federal tax implications of investing in the
Fund. You may wish to consult your own tax adviser. Additionally, state or local
taxes may apply to your investment, depending upon the laws of your state of
residence.
    
 
TAXES ON DISTRIBUTIONS
   
Dividends and distributions by the Fund are subject to federal income tax,
regardless of whether the distribution is made in cash or reinvested in
additional shares of the Fund. In certain states, a portion of the dividends and
distributions (depending on the source of the Fund's income) may be exempt from
state and local taxes. Information regarding the tax status of income dividends
and capital gains distributions will be mailed to shareholders on or before
January 31st of each year. Account tax information will also be sent to the IRS.
    
 
TAXATION OF THE FUND
   
The Fund may from year to year make the election permitted under section 853 of
the Internal Revenue Code to pass through such taxes to shareholders as a
foreign tax credit. If such an election is not made, any foreign taxes paid or
accrued will represent an expense to the Fund which will reduce its investment
income.
    
 
The Fund does not expect to pay any federal income or excise taxes because it
intends to meet certain requirements of the Internal Revenue Code. It is
important that the Fund meet these requirements so that any earnings on your
investment will not be taxed twice.
 
   
 32   JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998
    
<PAGE>   
 
                                   APPENDIX A
 
GLOSSARY OF INVESTMENT TERMS
This glossary provides a more detailed description of some of the types of
securities and other instruments in which the Fund may invest. The Fund may
invest in these instruments to the extent permitted by its investment objective
and policies. The Fund is not limited by this discussion and may invest in any
other types of instruments not precluded by the policies discussed elsewhere in
this Prospectus. Please refer to the SAI for a more detailed discussion of
certain instruments.
 
I. EQUITY AND DEBT SECURITIES
   
BONDS are debt securities issued by a company, municipality, government or
government agency. The issuer of a bond is required to pay the holder the amount
of the loan (or par value of the bond) at a specified maturity and to make
scheduled interest payments.
    
 
COMMERCIAL PAPER is a short-term debt obligation with a maturity ranging from 1
to 270 days issued by banks, corporations and other borrowers to investors
seeking to invest idle cash. For example, the Fund may purchase commercial paper
issued under Section 4(2) of the Securities Act of 1933.
 
COMMON STOCK represents a share of ownership in a company, and usually carries
voting rights and earns dividends. Unlike preferred stock, dividends on common
stocks are not fixed but are declared at the discretion of the issuer's board of
directors.
 
CONVERTIBLE SECURITIES are preferred stocks or bonds that pay a fixed dividend
or interest payment and are convertible into common stock at a specified price
or conversion ratio.
 
DEPOSITARY RECEIPTS are receipts for shares of a foreign-based corporation that
entitle the holder to dividends and capital gains on the underlying security.
Receipts include those issued by domestic banks (American Depositary Receipts),
foreign banks (Global or European Depositary Receipts) and broker-dealers
(depositary shares).
 
   
FIXED-INCOME SECURITIES are securities that pay a specified rate of return. The
term generally includes short- and long-term government, corporate and municipal
obligations that pay a specified rate of interest or coupons for a specified
period of time, and preferred stock, which pays fixed dividends. Coupon and
dividend rates may be fixed for the life of the issue or, in the case of
adjustable and floating rate securities, for a shorter period.
    
 
HIGH-YIELD/HIGH-RISK SECURITIES are securities that are rated below investment
grade by the primary rating agencies (e.g., BB or lower by Standard & Poor's and
Ba or lower by Moody's). Other terms commonly used to describe such securities
include "lower rated bonds," "noninvestment grade bonds" and "junk bonds."
 
MORTGAGE- AND ASSET-BACKED SECURITIES are shares in a pool of mortgages or other
debt. These securities are generally pass-through securities, which means that
principal and interest payments on the underlying securities (less servicing
fees) are passed
 
   
JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998    33
    
<PAGE>   
 
through to shareholders on a pro rata basis. These securities involve prepayment
risk, which is the risk that the underlying mortgages or other debt may be
refinanced or paid off prior to their maturities during periods of declining
interest rates. In that case, the portfolio managers may have to reinvest the
proceeds from the securities at a lower rate. Potential market gains on a
security subject to prepayment risk may be more limited than potential market
gains on a comparable security that is not subject to prepayment risk.
 
   
PASSIVE FOREIGN INVESTMENT COMPANIES (PFICS) are any foreign corporations which
generate certain amounts of passive income or hold certain amounts of assets for
the production of passive income. Passive income includes dividends, interest,
royalties, rents and annuities. To avoid taxes and interest that the Fund must
pay if these investments are profitable, the Fund may make various elections
permitted by the tax laws. These elections could require that the Fund recognize
taxable income, which in turn must be distributed, before the securities are
sold and before cash is received to pay the distributions.
    
 
PAY-IN-KIND BONDS are debt securities that normally give the issuer an option to
pay cash at a coupon payment date or give the holder of the security a similar
bond with the same coupon rate and a face value equal to the amount of the
coupon payment that would have been made.
 
PREFERRED STOCK is a class of stock that generally pays dividends at a specified
rate and has preference over common stock in the payment of dividends and
liquidation. Preferred stock generally does not carry voting rights.
 
REPURCHASE AGREEMENTS involve the purchase of a security by the Fund and a
simultaneous agreement by the seller (generally a bank or dealer) to repurchase
the security from the Fund at a specified date or upon demand. This technique
offers a method of earning income on idle cash. These securities involve the
risk that the seller will fail to repurchase the security, as agreed. In that
case, the Fund will bear the risk of market value fluctuations until the
security can be sold and may encounter delays and incur costs in liquidating the
security.
 
   
REVERSE REPURCHASE AGREEMENTS involve the sale of a security by the Fund to
another party (generally a bank or dealer) in return for cash and an agreement
by the Fund to buy the security back at a specified price and time. This
technique will be used primarily to provide cash to satisfy unusually heavy
redemption requests, or for other temporary or emergency purposes.
    
 
RULE 144A SECURITIES are securities that are not registered for sale to the
general public under the Securities Act of 1933, but that may be resold to
certain institutional investors.
 
STANDBY COMMITMENTS are obligations purchased by the Fund from a dealer that
give the Fund the option to sell a security to the dealer at a specified price.
 
STEP COUPON BONDS are debt securities that trade at a discount from their face
value and pay coupon interest. The discount from their face value depends on the
time remaining until cash payments begin, prevailing interest rates, liquidity
of the security and the perceived credit quality of the issuer.
 
   
 34   JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998
    
<PAGE>   
 
STRIP BONDS are debt securities that are stripped of their interest (usually by
a financial intermediary) after the securities are issued. The market value of
these securities generally fluctuates more in response to changes in interest
rates than interest-paying securities of comparable maturity.
 
U.S. GOVERNMENT SECURITIES include direct obligations of the U.S. government
that are supported by its full faith and credit. Treasury bills have initial
maturities of less than one year, Treasury notes have initial maturities of one
to ten years and Treasury bonds may be issued with any maturity but generally
have maturities of at least ten years. U.S. government securities also include
indirect obligations of the U.S. government that are issued by federal agencies
and government sponsored entities. Unlike Treasury securities, agency securities
generally are not backed by the full faith and credit of the U.S. government.
Some agency securities are supported by the right of the issuer to borrow from
the Treasury, others are supported by the discretionary authority of the U.S.
government to purchase the agency's obligations and others are supported only by
the credit of the sponsoring agency.
 
WARRANTS are securities, typically issued with preferred stocks or bonds, that
give the holder the right to buy a proportionate amount of common stock at a
specified price, usually at a price that is higher than the market price at the
time of issuance of the warrant. The right may last for a period of years or
indefinitely.
 
WHEN-ISSUED, DELAYED DELIVERY AND FORWARD TRANSACTIONS generally involve the
purchase of a security with payment and delivery at some time in the
future - i.e., beyond normal settlement. The Fund does not earn interest on such
securities until settlement and bears the risk of market value fluctuations in
between the purchase and settlement dates. New issues of stocks and bonds,
private placements and U.S. government securities may be sold in this manner.
 
ZERO COUPON BONDS are debt securities that do not pay interest at regular
intervals, but are issued at a discount from face value. The discount
approximates the total amount of interest the security will accrue from the date
of issuance to maturity. The market value of these securities generally
fluctuates more in response to changes in interest rates than interestpaying
securities of comparable maturity.
 
II. FUTURES, OPTIONS AND OTHER DERIVATIVES
   
FORWARD CONTRACTS are contracts to purchase or sell a specified amount of a
financial instrument for an agreed upon price at a specified time. Forward
contracts are not currently exchange traded and are typically negotiated on an
individual basis. The Fund may enter into forward currency contracts to hedge
against declines in the value of securities denominated in, or whose value is
tied to, a currency other than the U.S. dollar or to reduce the impact of
currency appreciation on purchases of such securities. It may also enter into
forward contracts to purchase or sell securities or other financial indices.
    
 
FUTURES CONTRACTS are contracts that obligate the buyer to receive and the
seller to deliver an instrument or money at a specified price on a specified
date. The Fund may buy and sell futures contracts on foreign currencies,
securities and financial indices including interest rates or an index of U.S.
government, foreign government, equity or fixed-income securities. The Fund may
also buy options on futures contracts. An option
   
JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998    35
    
<PAGE>   
 
on a futures contract gives the buyer the right, but not the obligation, to buy
or sell a futures contract at a specified price on or before a specified date.
Futures contracts and options on futures are standardized and traded on
designated exchanges.
 
INDEXED/STRUCTURED SECURITIES are typically short- to intermediate-term debt
securities whose value at maturity or interest rate is linked to currencies,
interest rates, equity securities, indices, commodity prices or other financial
indicators. Such securities may be positively or negatively indexed (i.e., their
value may increase or decrease if the reference index or instrument
appreciates). Indexed/structured securities may have return characteristics
similar to direct investments in the underlying instrument and may be more
volatile than the underlying instrument. The Fund bears the market risk of an
investment in the underlying instrument, as well as the credit risk of the
issuer.
 
INTEREST RATE SWAPS involve the exchange by two parties of their respective
commitments to pay or receive interest (e.g., an exchange of floating rate
payments for fixed rate payments).
 
OPTIONS are the right, but not the obligation, to buy or sell a specified amount
of securities or other assets on or before a fixed date at a predetermined
price. The Fund may purchase and write put and call options on securities,
securities indices and foreign currencies.
 
   
 36   JANUS VENTURE FUND PROSPECTUS                            FEBRUARY 17, 1998
    
<PAGE>   
 
                       This page intentionally left blank
<PAGE>   
 
                       This page intentionally left blank


<PAGE>   
 
                            JANUS MONEY MARKET FUND
                       JANUS GOVERNMENT MONEY MARKET FUND
                       JANUS TAX-EXEMPT MONEY MARKET FUND
 
                              Institutional Shares
                              100 Fillmore Street
                             Denver, CO 80206-4928
                                 (800) 29JANUS
 
   
                               FEBRUARY 17, 1998
    
 
Janus Money Market Fund, Janus Government Money Market Fund, and Janus Tax-
Exempt Money Market Fund (individually, a "Fund" and, collectively, the "Funds")
are designed for investors who seek maximum current income consistent with
stability of capital. This prospectus offers a separate class of shares of each
Fund (collectively, the "Shares") exclusively to institutional and individual
clients meeting minimum investment requirements. Each Fund is a separate series
of Janus Investment Fund (the "Trust"), an open-end management investment
company.
 
Each Fund invests exclusively in high quality money market instruments. AN
INVESTMENT IN A FUND IS NEITHER INSURED NOR GUARANTEED BY THE U.S. GOVERNMENT.
THERE IS NO ASSURANCE THAT A FUND WILL BE ABLE TO MAINTAIN A STABLE NET ASSET
VALUE OF $1.00 PER SHARE.
 
   
The Shares are offered with no sales charges, commissions, redemption fees, Rule
12b-1 fees or deferred sales charges. The minimum initial investment is
$250,000. There is no minimum amount required for subsequent investments. For
complete details on how to purchase, redeem and exchange Shares, please see the
Shareholder's Guide beginning at page 18.
    
 
   
This prospectus contains information about the Shares that prospective investors
should consider before investing and should be read carefully and retained for
future reference. Additional information about the Shares is contained in the
Statement of Additional Information ("SAI") dated February 17, 1998, which is
filed with the Securities and Exchange Commission ("SEC") and is incorporated by
reference into this Prospectus. The SAI is available upon request and without
charge by writing or calling the Funds at the address or telephone number shown
above. The SEC maintains a Web site located at http://www.sec.gov that contains
the SAI, material incorporated by reference, and other information regarding the
Funds.
    
 
   
THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SEC OR ANY STATE
SECURITIES COMMISSION NOR HAS THE SEC OR ANY STATE SECURITIES COMMISSION PASSED
UPON THE ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE
CONTRARY IS A CRIMINAL OFFENSE.
    
 
THIS PROSPECTUS DOES NOT CONSTITUTE AN OFFER TO SELL SECURITIES IN ANY STATE OR
OTHER JURISDICTION TO ANY PERSON TO WHOM IT IS UNLAWFUL TO MAKE SUCH AN OFFER IN
SUCH STATE OR OTHER JURISDICTION.
 
   
JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS          FEBRUARY 17,
                                                                       1998    1
    
<PAGE>   
 
                                    CONTENTS
 
   
<TABLE>
<S>                                            <C>
FEE TABLE....................................    3
FINANCIAL HIGHLIGHTS.........................    4
INVESTMENT OBJECTIVES, POLICIES AND
  TECHNIQUES.................................    6
INVESTMENT ADVISER AND
  ADMINISTRATOR..............................   13
DISTRIBUTIONS AND TAXES......................   14
PERFORMANCE..................................   16
MISCELLANEOUS INFORMATION....................   16
SHAREHOLDER'S GUIDE
How to Open an Account.......................   18
Purchasing Shares............................   18
How to Exchange Shares.......................   20
How to Redeem Shares.........................   20
Special Shareholder Services and Other
  Information................................   21
</TABLE>
    
 
   
 2   JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS     FEBRUARY 17,
1998
    
<PAGE>   
 
                                   FEE TABLE
 
    SHAREHOLDER TRANSACTION EXPENSES (Applicable to each Fund)
 
<TABLE>
         <S>                                              <C>
         Sales Load Imposed on Purchases                  None
         Sales Load Imposed on Reinvested Dividends       None
         Deferred Sales Load                              None
         Redemption Fees                                  None
         Exchange Fee                                     None
</TABLE>
 
ANNUAL OPERATING EXPENSES*
(Expressed as a percentage of average net assets)
 
   
<TABLE>
<CAPTION>
- -----------------------------------------------------------------------------
                                      MANAGEMENT    OTHER     TOTAL OPERATING
                                         FEE       EXPENSES      EXPENSES
- -----------------------------------------------------------------------------
<S>                                   <C>          <C>        <C>
 
Janus Money Market Fund -
  Institutional Shares                  0.10%       0.05%         0.15%
Janus Government Money Market Fund -
  Institutional Shares                  0.10%       0.05%         0.15%
Janus Tax-Exempt Money Market Fund -
  Institutional Shares                  0.10%       0.05%         0.15%
</TABLE>
    
 
- --------------------------------------------------------------------------------
 
   
* The information in the table above is based on expenses for the fiscal year
  ended October 31, 1997, net of fee waivers from the investment adviser.
  Without such waivers, the Management Fee, Other Expenses and Total Operating
  Expenses would have been 0.20%, 0.15% and 0.35%, respectively. Janus Capital
  may modify or terminate the waivers at any time upon at least 90 days' notice
  to the Trustees. See "Investment Adviser and Administrator" for a more
  detailed discussion of the fees.
    
 
EXAMPLE
You would indirectly pay the following expenses on a $1,000 investment, assuming
expense ratios remain as listed above and assuming a 5% annual return, with or
without redemption at the end of each period:
 
   
<TABLE>
<CAPTION>
                                          1 YEAR  3 YEARS  5 YEARS  10 YEARS
<S>                                       <C>     <C>      <C>      <C>
============================================================================
 
Janus Money Market Fund - Institutional
  Shares                                    $2      $5       $8       $19
Janus Government Money Market Fund -
  Institutional Shares                      $2      $5       $8       $19
Janus Tax-Exempt Money Market Fund -
  Institutional Shares                      $2      $5       $8       $19
</TABLE>
    
 
- --------------------------------------------------------------------------------
 
THE EXPENSES IN THE EXAMPLE ABOVE SHOULD NOT BE CONSIDERED A REPRESENTATION OF
PAST OR FUTURE EXPENSES AND ACTUAL EXPENSES MAY BE GREATER OR LESS THAN THOSE
SHOWN. THE ASSUMED 5% ANNUAL RETURN IS HYPOTHETICAL AND SHOULD NOT BE CONSIDERED
A REPRESENTATION OF PAST OR FUTURE ANNUAL RETURNS, WHICH MAY BE GREATER OR LESS
THAN THE ASSUMED AMOUNT.
 
The purpose of the preceding table and example is to assist the investor in
understanding the various costs and expenses that an investor in each Fund will
bear directly or indirectly. These expenses are described in greater detail
under "Investment Adviser and Administrator."
   
JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS          FEBRUARY 17,
                                                                       1998    3
    
<PAGE>   
 
                              FINANCIAL HIGHLIGHTS
 
The information below is for fiscal periods ending October 31 of each year. The
accounting firm of Price Waterhouse LLP has audited the Funds' financial
statements and their report is included in the Funds' Annual Report, which is
incorporated by reference into the SAI.
 
   
<TABLE>
<CAPTION>
                                                   JANUS                   JANUS GOVERNMENT
                                                MONEY MARKET                 MONEY MARKET
                                                    FUND                         FUND
         INSTITUTIONAL SHARES            1997+     1996     1995(1)    1997+    1996     1995(1)
<S>                                      <C>       <C>      <C>        <C>      <C>      <C>
- ------------------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF
    PERIOD                                         $1.00     $1.00              $1.00    $1.00
- ------------------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income                            .05       .03               .05       .03
 3. Net gains or (losses) on securities
    (both realized and unrealized)                    --        --                --        --
- ------------------------------------------------------------------------------------------------
 4. Total from investment operations                 .05       .03               .05       .03
- ------------------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment
    income)                                        (.05)     (.03)              (.05)     (.03)
 6. Distributions (from capital gains)                --        --                --        --
- ------------------------------------------------------------------------------------------------
 7. Total distributions                            (.05)     (.03)              (.05)     (.03)
- ------------------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                 $1.00     $1.00              $1.00    $1.00
- ------------------------------------------------------------------------------------------------
 9. Total return*                                  5.61%     3.25%              5.50%     3.20%
- ------------------------------------------------------------------------------------------------
10. Net assets, end of period (in
    thousands)                                     $1,706     $305               $59       $44
11. Average net assets for the period
    (millions)                                      $874      $202               $53       $25
12. Ratio of expenses to average net
    assets**                                       0.15%(2)  0.15%(2)           0.15%(2)  0.15%(2)
13. Ratio of net investment income to
    average net assets**                           5.41%     5.86%              5.34%     5.75%
- ------------------------------------------------------------------------------------------------
</TABLE>
    
 
(1) Period from April 17, 1995 (inception) through October 31, 1995.
(2) The ratio was .35% before voluntary reduction of fees.
 * Total return is not annualized for periods of less than one full year.
** Annualized for periods of less than one full year.
   
 + [To be filed by Amendment]
    
 
   
 4   JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS     FEBRUARY 17,
1998
    
<PAGE>   
 
   
(continued)
    
 
   
<TABLE>
<CAPTION>
                                                                   JANUS TAX-EXEMPT
                                                                     MONEY MARKET
                                                                         FUND
                    INSTITUTIONAL SHARES                      1997+     1996     1995(1)
<S>                                                           <C>       <C>      <C>
- ----------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD                                $1.00    $1.00
- ----------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income                                                 .04      .02
 3. Net gains or (losses) on securities (both realized and
    unrealized)                                                            --       --
- ----------------------------------------------------------------------------------------
 4. Total from investment operations                                      .04      .02
- ----------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)                              (.04)     (.02)
 6. Distributions (from capital gains)                                     --       --
- ----------------------------------------------------------------------------------------
 7. Total distributions                                                 (.04)     (.02)
- ----------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD                                      $1.00    $1.00
- ----------------------------------------------------------------------------------------
 9. Total return*                                                       3.74%     2.09%
- ----------------------------------------------------------------------------------------
10. Net assets, end of period (in thousands)                               $2      $11
11. Average net assets for the period (millions)                           $2       $1
12. Ratio of expenses to average net assets**                           0.15%(2)  0.15%(2)
13. Ratio of net investment income to average net assets**              3.82%     3.82%
- ----------------------------------------------------------------------------------------
</TABLE>
    
 
(1) Period from April 17, 1995 (inception) through October 31, 1995.
(2) The ratio was .35% before voluntary reduction of fees.
 * Total return is not annualized for periods of less than one full year.
** Annualized for periods of less than one full year.
   
    + [To be filed by Amendment]
    
 
   
JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS          FEBRUARY 17,
                                                                       1998    5
    
<PAGE>   
 
                             INVESTMENT OBJECTIVES,
                            POLICIES AND TECHNIQUES
 
Unless otherwise stated, the investment objectives and policies set forth in
this Prospectus are not fundamental and may be changed by the Trustees of the
Trust (the "Trustees") without shareholder approval. Shareholders will be
notified of material changes in investment objectives or policies. If there is a
change in the investment objective or policies of any Fund, shareholders should
consider whether that Fund remains an appropriate investment in light of their
then current financial position and needs. The Funds are subject to additional
investment policies and restrictions described in the SAI, some of which are
fundamental and may not be changed without shareholder approval.
 
INVESTMENT OBJECTIVES
The investment objective of Janus Money Market Fund and Janus Government Money
Market Fund is to seek maximum current income to the extent consistent with
stability of capital. The investment objective of Janus Tax-Exempt Money Market
Fund is to seek maximum current income that is exempt from federal income taxes
to the extent consistent with stability of capital. There can be no assurance
that a Fund will achieve its investment objective or that the Shares will be
able to maintain a stable net asset value of $1.00 per share.
 
COMMON INVESTMENT POLICIES
The Funds will invest only in eligible high quality, short-term money market
instruments that present minimal credit risks, as determined by Janus Capital
Corporation, the Funds' investment adviser ("Janus Capital"), pursuant to
procedures adopted by the Trustees. Each Fund may invest only in U.S.
dollar-denominated instruments that have a remaining maturity of 397 days or
less (as calculated pursuant to Rule 2a-7 under the Investment Company Act of
1940 ("1940 Act")) and will maintain a dollar-weighted average portfolio
maturity of 90 days or less.
 
Except to the limited extent permitted by Rule 2a-7 and except for U.S.
Government Securities (as defined below), each Fund will not invest more than 5%
of its total assets in the securities of any one issuer. A guarantor is not
considered an issuer for the purpose of this limit, provided that the value of
all securities held by a Fund that are issued or guaranteed by that institution
does not exceed 10% of the Fund's total assets. Until pending amendments to Rule
2a-7 become effective, up to 25% of Janus Tax-Exempt Money Market Fund's total
assets may be invested without regard to the foregoing limitations. A Fund may
not invest more than 25% of its total assets in any one industry, except that
this limit does not apply to U.S. Government Securities, bank obligations or
municipal securities. To ensure adequate liquidity, no Fund may invest more than
10% of its net assets in illiquid investments, including repurchase agreements
maturing in more than seven days (unless subject to a demand feature) and
certain time deposits that are subject to early withdrawal penalties and mature
in more than seven days. Because the Funds are typically used as a cash
management vehicle, they intend to
 
   
 6   JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS     FEBRUARY 17,
1998
    
<PAGE>   
 
maintain a high degree of liquidity. Janus Capital determines and monitors the
liquidity of portfolio securities under the supervision of the Trustees.
 
RATINGS
High quality money market instruments include those that (i) are rated (or, if
unrated, are issued by an issuer with comparable outstanding short-term debt
that is rated) in one of the two highest rating categories for short-term debt
by any two nationally recognized statistical rating organizations ("NRSROs") or,
if only one NRSRO has issued a rating, by that NRSRO or (ii) are otherwise
unrated and determined by Janus Capital to be of comparable quality. Each Fund,
except Janus Tax-Exempt Money Market Fund, will invest at least 95% of its total
assets in securities in the highest rating category (as determined pursuant to
Rule 2a-7). Descriptions of the rating categories of Standard & Poor's Ratings
Services, Moody's Investors Service, Inc., and certain other NRSROs are
contained in the SAI, as is a further description of the Funds' investment
policies.
 
Although each Fund only invests in high quality money market instruments, an
investment in a Fund is subject to risk even if all securities in its portfolio
are paid in full at maturity. All money market instruments, including U.S.
Government Securities, can change in value as a result of changes in interest
rates, the issuer's actual or perceived creditworthiness or the issuer's ability
to meet its obligations.
 
TYPES OF INVESTMENTS
 
JANUS MONEY MARKET FUND
Janus Money Market Fund pursues its objective by investing primarily in high
quality debt obligations and obligations of financial institutions. The Fund may
also invest in U.S. Government Securities (as defined below) and municipal
securities, although the Fund expects to invest in such securities to a lesser
degree.
 
DEBT OBLIGATIONS
The Fund may invest in debt obligations of domestic issuers, including
commercial paper (short-term promissory notes issued by companies to finance
their, or their affiliates', current obligations), notes and bonds, and variable
amount master demand notes. The payment obligations on these instruments may be
backed by securities, swap agreements or other assets, by the guarantee of a
third party or solely by the unsecured promise of the issuer to make payments
when due. The Fund may invest in privately issued commercial paper or other
securities that are restricted as to disposition under the federal securities
laws. In general, sales of these securities may not be made absent registration
under the Securities Act of 1933 (the "1933 Act") or the availability of an
appropriate exemption. Pursuant to Section 4(2) of the 1933 Act or Rule 144A
adopted under the 1933 Act, however, some of these securities are eligible for
resale to institutional investors, and accordingly, Janus Capital may determine
that a liquid market exists for such a security pursuant to guidelines adopted
by the Trustees.
 
OBLIGATIONS OF FINANCIAL INSTITUTIONS
   
The Fund may invest in obligations of financial institutions. Examples of
obligations in which the Fund may invest include negotiable certificates of
deposit, bankers' acceptances, time deposits and other obligations of U.S. banks
(including savings and loan associations) having total assets in excess of one
billion dollars and U.S. branches of
    
 
   
JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS          FEBRUARY 17,
                                                                       1998    7
    
<PAGE>   
 
   
foreign banks having total assets in excess of ten billion dollars. The Fund may
also invest in Eurodollar and Yankee bank obligations as discussed below and
other U.S. dollar-denominated obligations of foreign banks having total assets
in excess of ten billion dollars that Janus Capital believes are of an
investment quality comparable to obligations of U.S. banks in which the Fund may
invest.
    
 
Certificates of deposit represent an institution's obligation to repay funds
deposited with it that earn a specified interest rate over a given period.
Bankers' acceptances are negotiable obligations of a bank to pay a draft which
has been drawn by a customer and are usually backed by goods in international
trade. Time deposits are non-negotiable deposits with a banking institution that
earn a specified interest rate over a given period. Fixed time deposits, which
are payable at a stated maturity date and bear a fixed rate of interest,
generally may be withdrawn on demand by the Fund but may be subject to early
withdrawal penalties that could reduce the Fund's yield. Unless there is a
readily available market for them, time deposits that are subject to early
withdrawal penalties and that mature in more than seven days will be treated as
illiquid securities.
 
   
Eurodollar bank obligations are dollar-denominated certificates of deposit or
time deposits issued outside the U.S. capital markets by foreign branches of
U.S. banks and by foreign banks. Yankee bank obligations are dollar-denominated
obligations issued in the U.S. capital markets by foreign banks.
    
 
   
Foreign, Eurodollar (and to a limited extent, Yankee) bank obligations are
subject to certain sovereign risks. One such risk is the possibility that a
foreign government might prevent dollar-denominated funds from flowing across
its borders. Other risks include: adverse political and economic developments in
a foreign country; the extent and quality of government regulation of financial
markets and institutions; the imposition of foreign withholding taxes; and
expropriation or nationalization of foreign issuers.
    
 
U.S. GOVERNMENT SECURITIES
The Fund may invest without limit in U.S. Government Securities as described
below under "Janus Government Money Market Fund."
 
MUNICIPAL SECURITIES
The Fund may invest in obligations of states, territories or possessions of the
United States and their subdivisions, authorities and corporations as described
below under "Janus Tax-Exempt Money Market Fund." These obligations may pay
interest that is exempt from federal income taxation.
 
JANUS GOVERNMENT MONEY MARKET FUND
Janus Government Money Market Fund pursues its objective by investing
exclusively in obligations issued and/or guaranteed as to principal and interest
by the United States government or by its agencies and instrumentalities and
repurchase agreements secured by such obligations.
 
U.S. GOVERNMENT SECURITIES
U.S. Government Securities shall have the meaning set forth in the 1940 Act. The
1940 Act defines U.S. Government Securities to include securities issued or
guaranteed by the U.S. government, its agencies and instrumentalities. U.S.
Government Securities may also include repurchase agreements collateralized by
and municipal securities escrowed
 
   
 8   JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS     FEBRUARY 17,
1998
    
<PAGE>   
 
with or refunded with U.S. government securities. U.S. Government Securities in
which the Fund may invest include U.S. Treasury securities and obligations
issued or guaranteed by U.S. government agencies and instrumentalities that are
backed by the full faith and credit of the U.S. government, such as those
guaranteed by the Small Business Administration or issued by the Government
National Mortgage Association. In addition, U.S. Government Securities in which
the Fund may invest include securities supported primarily or solely by the
creditworthiness of the issuer, such as securities of the Federal National
Mortgage Association, the Federal Home Loan Mortgage Corporation and the
Tennessee Valley Authority. There is no guarantee that the U.S. government will
support securities not backed by its full faith and credit. Accordingly,
although these securities have historically involved little risk of loss of
principal if held to maturity, they may involve more risk than securities backed
by the full faith and credit of the U.S. government.
 
JANUS TAX-EXEMPT MONEY MARKET FUND
Janus Tax-Exempt Money Market Fund pursues its objective by investing primarily
in municipal securities whose interest is exempt from federal income taxes,
including the federal alternative minimum tax. Although the Fund will attempt to
invest substantially all of its assets in municipal securities whose interest is
exempt from federal income taxes, the Fund reserves the right to invest up to
20% of its net assets in securities whose interest is federally taxable.
Additionally, when its portfolio manager is unable to locate investment
opportunities with desirable risk/reward characteristics, the Fund may invest
without limit in cash and cash equivalents, including obligations that may be
federally taxable (see "Taxable Investments").
 
MUNICIPAL SECURITIES
The municipal securities in which the Fund may invest include municipal notes
and short-term municipal bonds. Municipal notes are generally used to provide
for the issuer's short-term capital needs and generally have maturities of 397
days or less. Examples include tax anticipation and revenue anticipation notes,
which generally are issued in anticipation of various seasonal revenues, bond
anticipation notes, construction loan notes and tax-exempt commercial paper.
Short-term municipal bonds may include "general obligation bonds," which are
secured by the issuer's pledge of its faith, credit and taxing power for payment
of principal and interest; "revenue bonds," which are generally paid from the
revenues of a particular facility or a specific excise tax or other source; and
"industrial development bonds," which are issued by or on behalf of public
authorities to provide funding for various privately operated industrial and
commercial facilities. The Fund may also invest in high quality participation
interests in municipal securities. A more detailed description of various types
of municipal securities is contained in Appendix B in the SAI.
 
When the assets and revenues of an agency, authority, instrumentality or other
political subdivision are separate from those of the government creating the
issuing entity and a security is backed only by the assets and revenues of the
issuing entity, that entity will be deemed to be the sole issuer of the
security. Similarly, in the case of an industrial development bond backed only
by the assets and revenues of the non-governmental issuer, the non-governmental
issuer will be deemed to be the sole issuer of the bond.
 
   
JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS          FEBRUARY 17,
                                                                       1998    9
    
<PAGE>   
 
At times, the Fund may invest more than 25% of its total assets in tax-exempt
securities that are related in such a way that an economic, business, or
political development or change affecting one such security could similarly
affect the other securities; for example, securities whose issuers are located
in the same state, or securities whose interest is derived from revenues of
similar type projects. The Fund may also invest more than 25% of its assets in
industrial development bonds or participation interests therein.
 
Yields on municipal securities are dependent on a variety of factors, including
the general conditions of the money market and of the municipal bond and
municipal note markets, the size of a particular offering, the maturity of the
obligation and the rating of the issue. The achievement of the Fund's investment
objective is dependent in part on the continuing ability of the issuers of
municipal securities in which the Fund invests to meet their obligations for the
payment of principal and interest when due. Obligations of issuers of municipal
securities are subject to the provisions of bankruptcy, insolvency and other
laws affecting the rights and remedies of creditors, such as the Bankruptcy
Reform Act of 1978, as amended. Therefore, the possibility exists that, as a
result of litigation or other conditions, the ability of any issuer to pay, when
due, the principal of and interest on its municipal securities may be materially
affected.
 
MUNICIPAL LEASES
The Fund may invest in municipal leases or participation interests therein.
Municipal leases are municipal securities which may take the form of a lease or
an installment purchase or conditional sales contract. Municipal leases are
issued by state and local governments and authorities to acquire a wide variety
of equipment and facilities. Lease obligations may not be backed by the issuing
municipality's credit and may involve risks not normally associated with general
obligation bonds and other revenue bonds. For example, their interest may become
taxable if the lease is assigned and the holders may incur losses if the issuer
does not appropriate funds for the lease payment on an annual basis, which may
result in termination of the lease and possible default. Janus Capital may
determine that a liquid market exists for municipal lease obligations pursuant
to guidelines established by the Trustees.
 
TAXABLE INVESTMENTS
As discussed above, although the Fund will attempt to invest substantially all
of its assets in municipal securities whose interest is exempt from federal
income tax, the Fund may under certain circumstances invest in certain
securities whose interest is subject to such taxation. These securities include:
(i) short-term obligations of the U.S. government, its agencies or
instrumentalities, (ii) certificates of deposit, bankers' acceptances and
interest-bearing savings deposits of banks having total assets of more than one
billion dollars and whose deposits are insured by the Federal Deposit Insurance
Corporation, (iii) commercial paper and (iv) repurchase agreements as described
below covering any of the securities described in items (i)-(iii) above or any
other obligations of the U.S. government, its agencies or instrumentalities.
 
   
 10   JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS    FEBRUARY 17,
1998
    
<PAGE>   
 
COMMON INVESTMENT TECHNIQUES
PARTICIPATION INTERESTS
The Funds may invest in participation interests in any type of security in which
the Funds may invest. A participation interest gives a Fund an undivided
interest in the underlying securities in the proportion that the Fund's
participation interest bears to the total principal amount of the underlying
securities. Participation interests usually carry a demand feature, as described
below, backed by a letter of credit or guarantee of the institution that issued
the interests permitting the holder to tender them back to the institution.
 
DEMAND FEATURES
The Funds may invest in securities that are subject to puts and stand-by
commitments ("demand features"). Demand features give the Fund the right to
resell securities at specified periods prior to their maturity dates to the
seller or to some third party at an agreed-upon price or yield. Securities with
demand features may involve certain expenses and risks, including the inability
of the issuer of the instrument to pay for the securities at the time the
instrument is exercised, non-marketability of the instrument and differences
between the maturity of the underlying security and the maturity of the
instrument. Securities may cost more with demand features than without them.
Demand features can serve three purposes: to shorten the maturity of a variable
or floating rate security, to enhance the instrument's credit quality and to
provide a source of liquidity. Demand features are often issued by third party
financial institutions, generally domestic and foreign banks. Accordingly, the
credit quality and liquidity of the Funds' investments may be dependent in part
on the credit quality of the banks supporting the Funds' investments. This will
result in exposure to risks pertaining to the banking industry, including the
foreign banking industry. Brokerage firms and insurance companies also provide
certain liquidity and credit support. A substantial portion of the Janus Tax-
Exempt Money Market Fund's portfolio in particular may consist of securities
backed by banks and other financial institutions, and thus adverse changes in
the credit quality of these institutions could cause losses to the Fund and
affect its share price.
 
VARIABLE AND FLOATING RATE SECURITIES
The securities in which the Funds invest may have variable or floating rates of
interest. These securities pay interest at rates that are adjusted periodically
according to a specified formula, usually with reference to some interest rate
index or market interest rate. Securities with ultimate maturities of greater
than 397 days may be purchased only pursuant to Rule 2a-7. Under that Rule, only
those long-term instruments that have demand features which comply with certain
requirements and certain variable rate U.S. Government Securities may be
purchased. Similar to fixed rate debt instruments, variable and floating rate
instruments are subject to changes in value based on changes in market interest
rates or changes in the issuer's or guarantor's creditworthiness. The rate of
interest on securities purchased by a Fund may be tied to short-term Treasury or
other government securities or indices on securities that are permissible
investments of the Funds, as well as other money market rates of interest. The
Funds will not purchase securities whose values are tied to interest rates or
indices that are not appropriate for the duration and volatility standards of a
money market fund.
 
   
JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS          FEBRUARY 17,
                                                                      1998    11
    
<PAGE>   
 
MORTGAGE- AND ASSET-BACKED SECURITIES
Janus Money Market Fund and Janus Government Money Market Fund may purchase
fixed or adjustable rate mortgage-backed securities issued by the Government
National Mortgage Association, Federal National Mortgage Association, the
Federal Home Loan Mortgage Corporation, or other governmental or
government-related entities. In addition, Janus Money Market Fund may purchase
other asset-backed securities, including securities backed by automobile loans,
equipment leases or credit card receivables. These securities directly or
indirectly represent a participation in, or are secured by and payable from,
fixed or adjustable rate mortgage or other loans which may be secured by real
estate or other assets. Unlike traditional debt instruments, payments on these
securities include both interest and a partial payment of principal. Prepayments
of the principal of underlying loans may shorten the effective maturities of
these securities and may result in a Fund having to reinvest proceeds at a lower
interest rate.
 
REPURCHASE AGREEMENTS
Each Fund may seek additional income by entering into collateralized repurchase
agreements. Repurchase agreements are transactions in which a Fund purchases
securities and simultaneously commits to resell those securities to the seller
at an agreed-upon price on an agreed-upon future date. The resale price reflects
a market rate of interest that is not related to the coupon rate or maturity of
the purchased securities. If the seller of the securities underlying a
repurchase agreement fails to pay the agreed resale price on the agreed delivery
date, a Fund may incur costs in disposing of the collateral and may experience
losses if there is any delay in its ability to do so.
 
REVERSE REPURCHASE AGREEMENTS
Each Fund may enter into reverse repurchase agreements. Reverse repurchase
agreements are transactions in which a Fund sells a security and simultaneously
commits to repurchase that security from the buyer at an agreed upon price on an
agreed upon future date. This technique will be used primarily for temporary or
emergency purposes, such as meeting redemption requests.
 
DELAYED DELIVERY SECURITIES
Each Fund may purchase securities on a when-issued or delayed delivery basis.
Securities so purchased are subject to market price fluctuation from the time of
purchase but no interest on the securities accrues to a Fund until delivery and
payment for the securities take place. Accordingly, the value of the securities
on the delivery date may be more or less than the purchase price. Forward
commitments will be entered into only when a Fund has the intention of taking
possession of the securities, but a Fund may sell the securities before the
settlement date if deemed advisable.
 
BORROWING AND LENDING
   
Each Fund may borrow money for temporary or emergency purposes in amounts up to
25% of its total assets. A Fund may not mortgage or pledge securities except to
secure permitted borrowings. As a fundamental policy, a Fund will not lend
securities or other assets if, as a result, more than 25% of its total assets
would be lent to other parties. The Funds do not currently intend to engage in
securities lending; however, under the terms of an exemptive order received from
the SEC, each of the Funds may borrow
    
 
   
 12   JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS    FEBRUARY 17,
1998
    
<PAGE>   
 
   
money from or lend money to other funds that permit such transactions and are
advised by Janus Capital.
    
 
                             INVESTMENT ADVISER AND
                                 ADMINISTRATOR
 
INVESTMENT ADVISER
Each Fund has a separate Investment Advisory Agreement with Janus Capital, 100
Fillmore Street, Denver, Colorado 80206-4923. Janus Capital has served as
investment adviser to Janus Fund since 1970 and currently serves as investment
adviser to all of the Janus funds, as well as adviser or subadviser to other
mutual funds and individual, corporate, charitable and retirement accounts.
Kansas City Southern Industries, Inc., a publicly traded holding company whose
primary subsidiaries are engaged in transportation, information processing and
financial services ("KCSI"), owns approximately 83% of the outstanding voting
stock of Janus Capital. Thomas H. Bailey, the President and Chairman of the
Board of Janus Capital, owns approximately 12% of its voting stock and, by
agreement with KCSI, selects a majority of Janus Capital's Board.
 
Pursuant to the Investment Advisory Agreements, Janus Capital furnishes
continuous advice and recommendations concerning each Fund's investments. Each
of the Funds has agreed to compensate Janus Capital for its advisory services by
the monthly payment of a fee at the annual rate of 0.20% of the value of the
average daily net assets of each Fund. Janus Capital has agreed to waive a
portion of its fee and accordingly, the advisory fee of each Fund will be
calculated at the annual rate of 0.10% of the value of each Fund's average daily
net assets. Janus Capital may modify or terminate the waiver at any time upon at
least 90 days' notice to the Trustees.
 
ADMINISTRATOR
Each of the Funds has also entered into an Administration Agreement with Janus
Capital, pursuant to which Janus Capital furnishes certain administrative,
compliance and accounting services for the Funds, pays the costs of printing
reports and prospectuses for existing shareholders, provides office space for
the Funds and pays the salaries, fees and expenses of all Fund officers and of
those Trustees who are affiliated with Janus Capital. Administrative services
provided by Janus Capital under the Administration Agreements include custody
and transfer agency services. Janus Capital is paid an administration fee,
calculated daily and paid monthly, at the annual rate of 0.15% of the value of
the average daily net assets of each Fund attributable to Shares for services
rendered pursuant to the Administration Agreements. Janus Capital has agreed to
waive a portion of its fee and accordingly, the administration fee paid by the
Shares will be calculated at the annual rate of 0.05% of the value of each
Fund's average daily net assets attributable to the Shares. Janus Capital may
modify or terminate this waiver upon at least 90 days' notice to the Trustees.
 
Each Fund pays all of its expenses not assumed by Janus Capital, including
auditing fees and independent Trustees' fees and expenses.
 
   
JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS          FEBRUARY 17,
                                                                      1998    13
    
<PAGE>   
 
PORTFOLIO TRANSACTIONS
Purchases and sales of securities on behalf of each Fund are executed by brokers
and dealers selected by Janus Capital. Broker-dealers are selected on the basis
of their ability to obtain best price and execution for the Funds' transactions
and recognizing brokerage, research and other services provided to the Fund and
to Janus Capital. Janus Capital may also consider payments made by brokers
effecting transactions for a Fund (i) to the Fund or (ii) to other persons on
behalf of the Fund for services provided to the Fund for which it would be
obligated to pay. The Funds' Trustees have also authorized the Funds to place
portfolio transactions on an agency basis with a broker-dealer that is
affiliated with Janus Capital. Agency trades, if any, that are placed with such
affiliated party serve to reduce certain expenses of the Funds. The SAI further
explains the selection of broker-dealers.
 
PERSONAL INVESTING
Janus Capital does not permit portfolio managers to purchase and sell securities
for their own accounts, except under the limited exceptions contained in Janus
Capital's policy governing personal investing. Janus Capital's policy requires
investment and other personnel to conduct their personal investment activities
in a manner that Janus Capital believes is not detrimental to the Funds and
Janus Capital's other advisory clients. See the SAI for more detailed
information.
 
   
YEAR 2000
    
   
Many computer systems use six-digit fields to store dates. With the approach of
the year 2000, these fields must be converted to eight-digit fields in order to
recognize the difference between 1900 and 2000. Failure to adequately address
this issue could have potentially serious repercussions. Preparing for Year 2000
is a high priority for Janus Capital, which has established a dedicated group to
address this issue and has entered into a consulting arrangement with one of the
foremost experts in Year 2000 compliance to assess systems implications for
Janus Capital. Janus Capital does not anticipate that the move to Year 2000 will
have a material impact on its ability to continue to provide the Funds with
service at current levels.
    
 
                            DISTRIBUTIONS AND TAXES
 
Dividends representing substantially all of the net investment income and any
net realized gains on sales of securities are declared daily, Saturdays, Sundays
and holidays included, and distributed on the last business day of each month.
If a month begins on a Saturday, Sunday or holiday, dividends for those days are
declared at the end of the preceding month and distributed on the first business
day of the month. Distributions will be reinvested in Shares of a Fund or wired
to a predesignated bank account at the election of the shareholder. If no
election is made, all distributions will be reinvested in additional Shares of a
Fund.
 
Shares purchased by wire on a day on which the Funds calculate their net asset
value and the Federal Reserve Banks are open ("bank business day") will receive
that day's dividend if the purchase is effected prior to 3:00 p.m. (New York
time) for the Janus
 
   
 14   JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS    FEBRUARY 17,
1998
    
<PAGE>   
 
Money Market and Janus Government Money Market Funds and 12:00 p.m. (New York
time) for the Janus Tax-Exempt Money Market Fund. Otherwise, such Shares begin
to accrue dividends on the first bank business day following receipt of the
order.
 
Redemption orders effected on any particular day will generally receive
dividends declared through the day of redemption. However, redemptions made by
wire which are received prior to 3:00 p.m. (New York time) for the Janus Money
Market and Janus Government Money Market Funds and 12:00 p.m. (New York time)
for Janus Tax-Exempt Money Market Fund will result in Shares being redeemed that
day. Proceeds of such a redemption will normally be sent to the predesignated
account on that day and that day's dividend will not be received. Requests for
redemptions made by wire which are received after 3:00 p.m. (12:00 p.m. for
Janus Tax-Exempt Money Market Fund) will be processed on that day and receive
that day's dividend, but will not be wired until the following bank business
day.
 
The Funds reserve the right to require purchase and redemption requests prior to
these times on days when the bond market closes before 4:00 p.m. (New York
time).
 
Distributions for all of the Funds (except Janus Tax-Exempt Money Market Fund)
are taxable income and are subject to federal income tax (except for
shareholders exempt from income tax), whether such distributions are received in
cash or are reinvested in additional Shares. Full information regarding the tax
status of income dividends and any capital gains distributions will be mailed to
shareholders for tax purposes on or before January 31st of each year. Because
the Funds are money market funds, they do not anticipate making any capital
gains distributions.
 
Janus Tax-Exempt Money Market Fund anticipates that substantially all income
dividends it pays will be exempt from federal income tax. However, dividends
attributable to interest on taxable investments, together with distributions
from any net realized capital gains, are taxable. In addition, interest on
certain private activity bonds is a preference item for purposes of the
individual and corporate alternative minimum taxes. To the extent that the Fund
earns such income, shareholders who are subject to the alternative minimum tax
must include such income as a preference item. The Fund will advise shareholders
of the percentage of dividends, if any, subject to the alternative minimum tax.
 
Dividends and capital gains distributions may also be subject to state and local
taxes. In certain states some portion of dividends and distributions (depending
on the sources of the Fund's net income) of Janus Tax-Exempt Money Market Fund
may be exempt from state and local taxes. Shareholders should consult their own
tax advisor regarding exemption from any applicable state and local tax, as well
as the tax treatment of any dividends or distributions from the Shares.
 
The Funds intend to comply with provisions of the Internal Revenue Code
applicable to investment companies, and thus it is not expected that any of the
Funds will be required to pay any federal income or excise taxes. The SAI
further explains the Funds' tax status.
 
   
JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS          FEBRUARY 17,
                                                                      1998    15
    
<PAGE>   
 
                                  PERFORMANCE
 
The Shares may measure performance in several ways, including "yield,"
"effective yield," and "tax equivalent yield" (for Janus Tax-Exempt Money Market
Fund only). Yield is a way of showing the rate of income the Shares earn on
investments as a percentage of the Share price. Yield represents the income,
less expenses generated by an investment, in the Shares over a seven-day period
expressed as an annual percentage rate. Effective yield is similar in that it is
calculated over the same time frame, but instead the net investment income is
compounded and then annualized. Due to the compounding effect, the effective
yield will normally be higher than the yield.
 
Shares of Janus Tax-Exempt Money Market Fund may also quote tax-equivalent
yield, which shows the taxable yield an investor would have to earn before taxes
to equal such Shares' tax-free yield. A tax-equivalent yield is calculated by
dividing such Shares' tax-exempt yield by the result of one minus a stated
federal tax rate. Only that portion of the Fund's income that is tax-exempt is
adjusted in this calculation.
 
Performance figures are based upon historical results and are not intended to
indicate future performance.
 
                           MISCELLANEOUS INFORMATION
 
ORGANIZATION
Each Fund is an open-end management investment company registered under the 1940
Act as a series of the Trust, which was created on February 11, 1986. Each Fund
currently offers three classes of shares by separate prospectuses. The Shares
offered by this Prospectus are available only to institutional clients,
including corporations, foundations and trusts, and individuals meeting certain
initial investment requirements. A second class of shares of each Fund, Service
Shares, are available only through Financial Institutions that meet minimum
investment requirements in connection with trust accounts, cash management
programs and similar programs. A third class of shares of each Fund, Investor
Shares, are available to the general public. Because the expenses of each class
may differ, the performance of each class is expected to differ. If you would
like additional information, please call Janus Extended Services at
1-800-29JANUS.
 
   
TRUSTEES
    
The Trustees oversee the business affairs of the Trust and are responsible for
major decisions relating to each Fund's investment objective and policies. The
Trustees delegate the day-to-day management of the Funds to the officers of the
Trust and meet at least quarterly to review the Funds' investment policies,
performance, expenses and other business affairs.
 
VOTING RIGHTS
The Trust is not required to hold annual shareholder meetings. However, special
meetings may be called for a specific class of shares, a specific Fund, or for
the Trust as a whole, for purposes such as electing or removing Trustees,
terminating or reorganizing
 
   
 16   JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS    FEBRUARY 17,
1998
    
<PAGE>   
 
the Trust, changing fundamental policies or voting on matters when required by
the 1940 Act. Separate votes are taken by a separate Fund (or a separate class
of shares) only if a matter affects or requires the vote of just that Fund (or
those shares). Shareholders are entitled to cast one vote for each Share they
own.
 
CUSTODIAN, TRANSFER AGENT AND DISTRIBUTOR
   
UMB Bank, N.A., P.O. Box 419226, Kansas City, Missouri 64141-6226, is the
custodian of the Funds' assets. The custodian holds each Fund's assets in
safekeeping and collects and remits the income thereon subject to the
instructions of each Fund.
    
 
Janus Service Corporation, P.O. Box 173375, Denver, Colorado 80217-3375, a
wholly-owned subsidiary of Janus Capital, provides transfer agency and
shareholder services for the Funds.
 
Janus Distributors, Inc., 100 Fillmore Street, Denver, Colorado 80206-4928, a
wholly-owned subsidiary of Janus Capital, is a distributor of the Shares.
 
   
JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS          FEBRUARY 17,
                                                                      1998    17
    
<PAGE>   
 
                              SHAREHOLDER'S GUIDE
 
HOW TO OPEN AN ACCOUNT
 
ESTABLISHING YOUR ACCOUNT
The Application enclosed with this Prospectus describes the options available to
you as an institutional shareholder of the Funds. After reviewing the
Application carefully, complete, sign and forward it to:
 
<TABLE>
<S>                      <C>
Via Regular Mail         Via Express Mail - Overnight Delivery
Janus                                                    Janus
P.O. Box 173375                            100 Fillmore Street
Denver, CO 80217-3375                    Denver, CO 80206-4928
Attn: Extended Services                Attn: Extended Services
</TABLE>
 
Do not include any purchase money with the Application. All purchases of Shares
should be effected by wire transfer. See "Purchasing Shares." The Funds reserve
the right to suspend the offering of the Shares for a period of time and to
reject any specific purchase request.
 
You may set up your account for Investment Retirement Plan rollovers (in excess
of $250,000) under a tax-sheltered retirement plan. A retirement plan allows you
to shelter your investment income from current income taxes. A contribution to
these plans may also be tax deductible. Distributions from a retirement plan are
generally subject to income tax and may be subject to an additional tax if
withdrawn prior to age 59 1/2.
 
   
Please refer to the Janus IRA booklet for complete information regarding IRAs.
You will need a special application to be enrolled in the plan. For an
application and more details, call 1-800-525-3713.
    
 
TAXPAYER IDENTIFICATION NUMBERS
On the application or other appropriate form, you will be asked to certify that
your Social Security or taxpayer identification number is correct and that you
are not subject to backup withholding for failing to report income to the IRS.
If you are subject to the 31% backup withholding or you did not certify your
taxpayer identification, the IRS requires the Funds to withhold 31% of any
dividends paid and redemption or exchange proceeds. In addition, to the 31%
backup withholding, you may be subject to a $50 fee to reimburse the Funds for
any penalty that the IRS may impose.
 
DISTRIBUTION OPTIONS
Shareholders have the option of having their dividends and distributions
automatically reinvested in Shares of a Fund or wired to a predesignated bank
account. If no election is made, all dividends and distributions will be
reinvested in additional Shares.
 
PURCHASING SHARES
You must establish a Fund account and receive an account number before making
purchases by wire. Requests to purchase Janus Money Market Fund and Janus
 
   
 18   JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS    FEBRUARY 17,
1998
    
<PAGE>   
 
   
Government Money Market Fund received before 3:00 p.m. (New York time) on a
business day will receive dividends declared on the purchase date. Requests to
purchase Janus Tax-Exempt Money Market Fund must be received before 12:00 p.m.
(New York time) on a business day in order to receive the dividend declared on
the day of purchase. In addition, the Funds' transfer agent must receive payment
in federal funds by 6:00 p.m. (New York time). If your payment on a purchase
order is not received by this time, your purchase may be canceled. You will be
responsible for any losses or expenses incurred by the Fund, Janus Capital,
Janus Service Corporation or Janus Distributors, Inc., and the Fund can redeem
shares you own in this or another identically registered Janus fund as
reimbursement. The Funds and their agent have the right to reject or cancel any
purchase, exchange, or redemption due to nonpayment. The Funds also reserve the
right to require purchase requests and payments prior to these times on days
when the bond market closes before 4:00 p.m. (New York time). Purchase orders
received after these times will receive the dividend declared the following day.
    
 
WIRE INSTRUCTIONS:
Request your bank to transmit immediately available funds by wire for purchase
of Shares to the Funds' custodian bank as follows:
 
United Missouri Bank, N.A., Kansas City, Missouri
ABA # 101000695
BNF = Janus Money Market Funds Account # 9870610000
For credit to: Name of Shareholder:
- -----------------------------------------------
               Shareholder Account No.:
             ---------------------------------------------------------
               Name of Fund(s):
             ----------------------------------------------------------------
 
Complete information regarding your account must be included in all wire
instructions in order to facilitate prompt and accurate handling of investments.
Please contact the Janus Extended Services Team at 1-800-29JANUS when you intend
to make a wire purchase.
 
The Funds do not charge any fees for transactions by wire in Shares of the
Funds.
 
Once you have established a Fund account, you may purchase Shares for such
account or open additional accounts with other Funds at any time. The Funds
reserve the right to suspend the offering of Shares for a period of time and to
reject any specific purchase request. If you have any questions, please call
1-800-29JANUS.
 
MINIMUM INVESTMENT
The minimum initial investment in the Shares is $250,000. The Funds may, in
their discretion, waive this minimum under certain circumstances but, in such
event, the minimum must be reached within 90 days of opening the account.
Shareholders who do not maintain the $250,000 minimum will be given the option
of exchanging into Investor Shares or having their Shares redeemed.
 
NET ASSET VALUE
The net asset value ("NAV") of the Shares is determined at the close of the
regular trading session of the New York Stock Exchange (normally 4:00 p.m., New
York time)
   
JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS          FEBRUARY 17,
                                                                      1998    19
    
<PAGE>   
 
each day that both the Exchange and the New York Federal Reserve Bank are open.
NAV per share is determined by dividing the total value of the securities and
other assets, less liabilities, by the total number of Shares outstanding.
Portfolio securities are valued at their amortized cost. Amortized cost
valuation involves valuing an instrument at its cost and thereafter assuming a
constant amortization to maturity (or such other date as permitted by Rule 2a-7)
of any discount or premium. If fluctuating interest rates cause the market value
of a portfolio to deviate more than 1/2 of 1% from the value determined on the
basis of amortized cost, the Trustees will consider whether any action, such as
adjusting the Share's NAV to reflect current market conditions, should be
initiated to prevent any material dilutive effect on shareholders.
 
SHARE CERTIFICATES
Share certificates are not available for the Shares in order to maintain the
general liquidity that is representative of a money market fund and to help
facilitate transactions in shareholder accounts.
 
HOW TO EXCHANGE SHARES
The Janus funds include several funds with a variety of investment objectives.
You may exchange your Shares for shares of any other Janus fund that is
available to the public and registered in your state of residence. There are
certain procedures which should be followed to effect the transfer of the entire
or partial balance in your Shares to one of the other Janus funds. The Funds
reserve the right to reject any exchange request and to modify or terminate the
exchange privilege at any time. For example, the Funds may reject exchanges from
accounts engaged in excessive trading (including market timing transactions)
that are detrimental to the Funds. If you would like more information regarding
this option, please call the Janus Extended Services Team at 1-800-29JANUS.
 
HOW TO REDEEM SHARES
PARTIAL OR COMPLETE REDEMPTIONS
You may redeem all or a portion of your Shares on any business day. Your Shares
will be redeemed at the NAV next calculated after your Fund has received your
redemption request in good order and meeting all the requirements of this
Prospectus. Proceeds of such redemption generally will be wired to your
predesignated bank account as of the day of redemption, or, if that day is a
bank holiday, on the next bank business day.
 
IN WRITING
To redeem all or part of your Shares in writing, send a letter of instruction to
the following address:
 
<TABLE>
<S>                      <C>
Via Regular Mail         Via Express Mail - Overnight Delivery
Janus                                                    Janus
P.O. Box 173375                            100 Fillmore Street
Denver, CO 80217-3375                    Denver, CO 80206-4928
Attn: Extended Services                Attn: Extended Services
</TABLE>
 
The letter should be on company letterhead (in the case of institutional
clients) and should specify the name of the Fund, the number of Shares or
dollars being redeemed,
 
   
 20   JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS    FEBRUARY 17,
1998
    
<PAGE>   
 
the account number, appropriate wiring instructions, the name(s) on the account,
your name and your daytime telephone number. The letter must be signed by an
authorized person whose signature is on file with the Fund.
 
   
For IRA shareholders, written instructions must be signed by the account owner.
If you do not want federal income tax withheld from your redemption, you must
state that you elect not to have such withholding apply. In addition, your
instructions must state whether the distribution is normal (after age 59 1/2) or
premature (before age 59 1/2) and, if premature, whether any exceptions apply
with regard to the 10% additional tax on early distributions.
    
 
BY TELEPHONE
Shares may be redeemed by telephone. If a request for a redemption is received
by 3:00 p.m. (New York time) for Janus Money Market Fund and Janus Government
Money Market Fund and by 12:00 p.m. (New York time) for Janus Tax-Exempt Money
Market Fund, Shares will be redeemed and the redemption amount wired in federal
funds to the shareholder's predesignated bank account that day. After 3:00 p.m.
(12:00 p.m. for Janus Tax-Exempt Money Market Fund), a redemption request will
be processed at that day's NAV and will include that day's dividends, but
generally will not be wired until the next bank business day. The Funds reserve
the right to require redemption requests prior to these times on days when the
bond market closes before 4:00 p.m. (New York time). There is no fee for
redemptions by wire.
 
BY A FUND
Your account may be terminated by your Fund if, due to the transfer or
redemption of Shares, the value of the remaining Shares in your account falls
below the minimum investment required to open a new account, or if you engage in
illegal or other conduct detrimental to the Funds. In the case of insufficient
account size, your Fund will notify you that you have 60 days to increase your
account to the minimum required before redeeming your account.
 
SPECIAL SHAREHOLDER SERVICES AND OTHER INFORMATION
 
PORTFOLIO INFORMATION
You may call 1-800-29JANUS by TouchTone(TM) telephone for access to certain
information regarding your account, including current yield and dividend rate
information, Monday through Friday from 7:00 a.m. to 10:00 p.m. (New York time).
 
TELEPHONE INSTRUCTIONS
You may initiate many transactions by telephone. The Funds and their agents will
not be responsible for any losses resulting from unauthorized transactions when
procedures designed to verify the identity of the caller are followed.
 
ACCOUNT ADDRESS AND NAME CHANGES
To change the address on your account, you may call 1-800-29JANUS or send a
written request signed by all registered owners of your account. Please include
the name of the Fund(s), the account number(s), the name(s) on the account and
both the old and new addresses. Within the first 10 days of an address change,
redemptions by institutional clients are permissible only if the redemption
proceeds are wired to a pre-designated
 
   
JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS          FEBRUARY 17,
                                                                      1998    21
    
<PAGE>   
 
bank account or you provide the Funds with appropriate corporate resolutions
changing wire instructions. Please call 1-800-29JANUS for additional
information.
 
To change the name on an account, the Shares must be transferred to a new
account. Such a change generally requires written instructions with the
guaranteed signatures of all registered owners, as well as an Application and
supporting legal documentation, if applicable. Please call 1-800-29JANUS for
additional information.
 
STATEMENTS AND REPORTS
Each shareholder will receive daily confirmations of purchases and redemptions
made in the Funds. On the last day of each month, the shareholder will receive a
statement reporting all purchases and redemptions made during that month, and
dividends paid during the month.
 
Twice each year you will receive the financial statements of the Funds,
including a statement listing portfolio securities. To reduce expenses, only one
copy of most reports (such as the Funds' Annual Report) may be mailed to all
accounts with the same tax identification number. Please call 1-800-29JANUS if
you need additional reports sent each time.
 
TEMPORARY SUSPENSION OF SERVICES
The Funds or their agents may temporarily suspend telephone transactions and
other shareholder services described in this Prospectus upon reasonable notice
or to the extent that any circumstance reasonably beyond the control of the
Funds or their agents materially hampers the provision of such services.
 
   
TRANSACTIONS THROUGH PROCESSING ORGANIZATIONS
    
   
You may purchase or sell Fund shares through a broker-dealer, bank or other
financial institution, or an organization that provides recordkeeping and
consulting services to retirement or other employee benefit plans (a "Processing
Organization"). Processing Organizations may charge you a fee for this service
and may require different minimum initial and subsequent investments than the
Funds. Processing Organizations may also impose other charges or restrictions
different from those applicable to shareholders who invest in the Funds
directly. A Processing Organization, rather than its customers, may be the
shareholder of record of your shares. The Funds are not responsible for the
failure of any Processing Organization to carry out its obligations to its
customers. Janus Capital or its affiliates, from their own assets, may
compensate certain Processing Organizations for providing administrative,
recordkeeping and similar services, as well as distribution-related services.
    
 
   
 22   JANUS MONEY MARKET FUNDS - INSTITUTIONAL SHARES PROSPECTUS    FEBRUARY 17,
1998
    

<PAGE>   
 
                            JANUS MONEY MARKET FUND
                       JANUS GOVERNMENT MONEY MARKET FUND
                       JANUS TAX-EXEMPT MONEY MARKET FUND
 
                                 Service Shares
                              100 Fillmore Street
                             Denver, CO 80206-4923
 
   
                               FEBRUARY 17, 1998
    
 
Janus Money Market Fund, Janus Government Money Market Fund, and Janus Tax-
Exempt Money Market Fund (individually, a "Fund" and, collectively, the "Funds")
are designed for investors who seek maximum current income consistent with
stability of capital. This prospectus offers a separate class of shares of each
Fund (collectively, the "Shares") exclusively through banks and other financial
institutions ("Financial Institutions") in connection with trust accounts, cash
management programs and similar programs provided to their customers. Each Fund
is a separate series of Janus Investment Fund (the "Trust"), an open-end
management investment company.
 
Each Fund invests exclusively in high quality money market instruments. AN
INVESTMENT IN A FUND IS NEITHER INSURED NOR GUARANTEED BY THE U.S. GOVERNMENT.
THERE IS NO ASSURANCE THAT A FUND WILL BE ABLE TO MAINTAIN A STABLE NET ASSET
VALUE OF $1.00 PER SHARE.
 
   
The Shares are offered with no sales charges, commissions, redemption fees, Rule
12b-1 fees or deferred sales charges. There is a $250,000 initial investment
minimum by each Financial Institution. The Financial Institution may aggregate
investments by all of its customers to achieve this minimum. There is no minimum
amount required for subsequent investments. For complete details on how to
purchase, redeem and exchange Shares, please see the Shareholder's Guide
beginning at page 18.
    
 
   
This prospectus contains information about the Shares that prospective investors
should consider before investing and should be read carefully and retained for
future reference. Additional information about the Shares is contained in the
Statement of Additional Information ("SAI") dated February 17, 1998, which is
filed with the Securities and Exchange Commission ("SEC") and is incorporated by
reference into this Prospectus. The SAI is available upon request and without
charge by writing or calling your Financial Institution. The SEC maintains a Web
site located at http://www.sec.gov that contains the SAI, material incorporated
by reference, and other information regarding the Funds.
    
 
   
THE FUNDS' SHARES ARE NOT BANK DEPOSITS, ARE NOT ENDORSED OR GUARANTEED BY ANY
BANK, AND ARE NOT INSURED BY THE FEDERAL DEPOSIT INSURANCE CORPORATION, THE
FEDERAL RESERVE BOARD, OR ANY OTHER GOVERNMENT AGENCY.
    
 
   
THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SEC OR ANY STATE
SECURITIES COMMISSION NOR HAS THE SEC OR ANY STATE SECURITIES COMMISSION PASSED
UPON THE ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE
CONTRARY IS A CRIMINAL OFFENSE.
    
 
THIS PROSPECTUS DOES NOT CONSTITUTE AN OFFER TO SELL SECURITIES IN ANY STATE OR
OTHER JURISDICTION TO ANY PERSON TO WHOM IT IS UNLAWFUL TO MAKE SUCH AN OFFER IN
SUCH STATE OR OTHER JURISDICTION.
 
   
JANUS MONEY MARKET FUNDS - SERVICE SHARES PROSPECTUS      FEBRUARY 17, 1998    1
    
<PAGE>   
 
                                    CONTENTS
 
   
<TABLE>
<S>                                            <C>
FEE TABLE....................................    3
FINANCIAL HIGHLIGHTS.........................    5
INVESTMENT OBJECTIVES, POLICIES AND
  TECHNIQUES.................................    6
INVESTMENT ADVISER AND
  ADMINISTRATOR..............................   13
DISTRIBUTIONS AND TAXES......................   15
PERFORMANCE..................................   16
MISCELLANEOUS INFORMATION....................   16
SHAREHOLDER'S GUIDE
Purchases....................................   18
Redemptions..................................   19
Shareholder Communications...................   19
</TABLE>
    
 
   
 2   JANUS MONEY MARKET FUNDS - SERVICE SHARES PROSPECTUS      FEBRUARY 17, 1998
    
<PAGE>   
 
                                   FEE TABLE
 
    SHAREHOLDER TRANSACTION EXPENSES
    (Applicable to each Fund)
 
<TABLE>
         <S>                                              <C>
         Sales Load Imposed on Purchases                  None
         Sales Load Imposed on Reinvested Dividends       None
         Deferred Sales Load                              None
         Redemption Fees                                  None
         Exchange Fee                                     None
</TABLE>
 
ANNUAL OPERATING EXPENSES(1)
(Expressed as a percentage of average net assets)
 
<TABLE>
<CAPTION>
- -------------------------------------------------------------------------------
                                   MANAGEMENT       OTHER       TOTAL OPERATING
                                     FEE(1)     EXPENSES(1,2)     EXPENSES(1)
- -------------------------------------------------------------------------------
<S>                                <C>          <C>             <C>
Janus Money Market Fund - Service
  Shares                             0.10%         0.30%            0.40%
Janus Government Money Market
  Fund - Service Shares              0.10%         0.30%            0.40%
Janus Tax-Exempt Money Market
  Fund - Service Shares              0.10%         0.30%            0.40%
</TABLE>
 
- --------------------------------------------------------------------------------
 
   
(1) The information in the table above is based on expenses for the fiscal
    period ended October 31, 1997, net of fee waivers from the investment
    adviser. Without such waivers, the Management Fee, Other Expenses and Total
    Operating Expenses for Service Shares would have been 0.20%, 0.40% and
    0.60%, respectively. Janus Capital may modify or terminate the waivers at
    any time upon at least 90 days' notice to the Trustees. See "Investment
    Adviser and Administrator" for a more detailed discussion of the fees.
    
 
   
(2) A portion of the administration fee included in "other expenses" may be used
    to compensate Financial Institutions for providing administrative services
    to their customers who invest in the Shares. See "Administrator" for more
    details. Certain Financial Institutions may charge additional fees directly
    to their customers for other services. Consult your Financial Institution to
    determine whether it charges any additional fees.
    
 
   
JANUS MONEY MARKET FUNDS - SERVICE SHARES PROSPECTUS      FEBRUARY 17, 1998    3
    
<PAGE>   
 
EXAMPLE
You would indirectly pay the following expenses on a $1,000 investment, assuming
expense ratios remain as listed above and assuming a 5% annual return, with or
without redemption at the end of each period:
 
   
<TABLE>
<CAPTION>
- ---------------------------------------------------------------------------
                                         1 YEAR  3 YEARS  5 YEARS  10 YEARS
- ---------------------------------------------------------------------------
<S>                                      <C>     <C>      <C>      <C>
Janus Money Market Fund - Service
  Shares                                   $4      $13      $22      $51
Janus Government Money Market Fund -
  Service Shares                           $4      $13      $22      $51
Janus Tax-Exempt Money Market Fund -
  Service Shares                           $4      $13      $22      $51
</TABLE>
    
 
- --------------------------------------------------------------------------------
 
THE EXPENSES IN THE EXAMPLE ABOVE SHOULD NOT BE CONSIDERED A REPRESENTATION OF
PAST OR FUTURE EXPENSES AND ACTUAL EXPENSES MAY BE GREATER OR LESS THAN THOSE
SHOWN. THE ASSUMED 5% ANNUAL RETURN IS HYPOTHETICAL AND SHOULD NOT BE CONSIDERED
A REPRESENTATION OF PAST OR FUTURE ANNUAL RETURNS, WHICH MAY BE GREATER OR LESS
THAN THE ASSUMED AMOUNT.
 
The purpose of the preceding table and example is to assist the investor in
understanding the various costs and expenses that an investor in each Fund will
bear directly or indirectly. These expenses are described in greater detail
under "Investment Adviser and Administrator."
 
   
 4   JANUS MONEY MARKET FUNDS - SERVICE SHARES PROSPECTUS      FEBRUARY 17, 1998
    
<PAGE>   
 
                              FINANCIAL HIGHLIGHTS
 
   
The information below is for the fiscal period ended October 31. The accounting
firm of Price Waterhouse LLP has audited the Funds' financial statements and
their report is included in the Funds' Annual Report, which is incorporated by
reference into the SAI.
    
 
   
<TABLE>
<CAPTION>
                                                              JANUS          JANUS
                                               JANUS        GOVERNMENT     TAX-EXEMPT
                                            MONEY MARKET   MONEY MARKET   MONEY MARKET
                                                FUND           FUND           FUND
                                            ------------   ------------   ------------
              SERVICE SHARES                  1997(1)        1997(1)        1997(1)
<S>                                         <C>            <C>            <C>
- ------------------------------------------------------------------------------------
 1. NET ASSET VALUE, BEGINNING OF PERIOD       $1.00
- ------------------------------------------------------------------------------------
   INCOME FROM INVESTMENT OPERATIONS:
 2. Net investment income
 3. Net gains or (losses) on securities
    (both realized and unrealized)                --
- ------------------------------------------------------------------------------------
 4. Total from investment operations
- ------------------------------------------------------------------------------------
   LESS DISTRIBUTIONS:
 5. Dividends (from net investment income)
 6. Distributions (from capital gains)            --
- ------------------------------------------------------------------------------------
 7. Total distributions
- ------------------------------------------------------------------------------------
 8. NET ASSET VALUE, END OF PERIOD             $1.00
- ------------------------------------------------------------------------------------
 9. Total return*                                  %
- ------------------------------------------------------------------------------------
10. Net assets, end of period (in
    thousands)                                     $
11. Average net assets for the period
    (millions)                                     $
12. Ratio of expenses to average net
    assets**                                    %(2)
13. Ratio of net investment income to
    average net assets**                           %
- ------------------------------------------------------------------------------------
</TABLE>
    
 
   
(1) Period from November 22, 1996 (inception) to October 31, 1997.
    
   
(2) The ratio was     % before voluntary reduction of fees.
    
   
 * Total return is not annualized for periods of less than one full year.
    
   
** Annualized for periods of less than one full year.
    
   
 + [To be filed by Amendment]
    
 
   
JANUS MONEY MARKET FUNDS - SERVICE SHARES PROSPECTUS      FEBRUARY 17, 1998    5
    
<PAGE>   
 
                             INVESTMENT OBJECTIVES,
                            POLICIES AND TECHNIQUES
 
Unless otherwise stated, the investment objectives and policies set forth in
this Prospectus are not fundamental and may be changed by the Trustees of the
Trust (the "Trustees") without shareholder approval. Shareholders will be
notified of material changes in investment objectives or policies. If there is a
change in the investment objective or policies of any Fund, shareholders should
consider whether that Fund remains an appropriate investment in light of their
then current financial position and needs. The Funds are subject to additional
investment policies and restrictions described in the SAI, some of which are
fundamental and may not be changed without shareholder approval.
 
INVESTMENT OBJECTIVES
The investment objective of Janus Money Market Fund and Janus Government Money
Market Fund is to seek maximum current income to the extent consistent with
stability of capital. The investment objective of Janus Tax-Exempt Money Market
Fund is to seek maximum current income that is exempt from federal income taxes
to the extent consistent with stability of capital. There can be no assurance
that a Fund will achieve its investment objective or that the Shares will be
able to maintain a stable net asset value of $1.00 per share.
 
COMMON INVESTMENT POLICIES
The Funds will invest only in eligible high quality, short-term money market
instruments that present minimal credit risks, as determined by Janus Capital
Corporation, the Funds' investment adviser ("Janus Capital"), pursuant to
procedures adopted by the Trustees. Each Fund may invest only in U.S.
dollar-denominated instruments that have a remaining maturity of 397 days or
less (as calculated pursuant to Rule 2a-7 under the Investment Company Act of
1940 ("1940 Act")) and will maintain a dollar-weighted average portfolio
maturity of 90 days or less.
 
Except to the limited extent permitted by Rule 2a-7 and except for U.S.
Government Securities (as defined below), each Fund will not invest more than 5%
of its total assets in the securities of any one issuer. A guarantor is not
considered an issuer for the purpose of this limit, provided that the value of
all securities held by a Fund that are issued or guaranteed by that institution
does not exceed 10% of the Fund's total assets. Until pending amendments to Rule
2a-7 become effective, up to 25% of Janus Tax-Exempt Money Market Fund's total
assets may be invested without regard to the foregoing limitations. A Fund may
not invest more than 25% of its total assets in any one industry, except that
this limit does not apply to U.S. Government Securities, bank obligations or
municipal securities. To ensure adequate liquidity, no Fund may invest more than
10% of its net assets in illiquid investments, including repurchase agreements
maturing in more than seven days (unless subject to a demand feature) and
certain time deposits that are subject to early withdrawal penalties and mature
in more than seven days. Because the Funds are typically used as a cash
management vehicle, they intend to
 
   
 6   JANUS MONEY MARKET FUNDS - SERVICE SHARES PROSPECTUS      FEBRUARY 17, 1998
    
<PAGE>   
 
maintain a high degree of liquidity. Janus Capital determines and monitors the
liquidity of portfolio securities under the supervision of the Trustees.
 
RATINGS
High quality money market instruments include those that (i) are rated (or, if
unrated, are issued by an issuer with comparable outstanding short-term debt
that is rated) in one of the two highest rating categories for short-term debt
by any two nationally recognized statistical rating organizations ("NRSROs") or,
if only one NRSRO has issued a rating, by that NRSRO or (ii) are otherwise
unrated and determined by Janus Capital to be of comparable quality. Each Fund,
except Janus Tax-Exempt Money Market Fund, will invest at least 95% of its total
assets in securities in the highest rating category (as determined pursuant to
Rule 2a-7). Descriptions of the rating categories of Standard & Poor's Ratings
Services, Moody's Investors Service, Inc., and certain other NRSROs are
contained in the SAI, as is a further description of the Funds' investment
policies.
 
Although each Fund only invests in high quality money market instruments, an
investment in a Fund is subject to risk even if all securities in its portfolio
are paid in full at maturity. All money market instruments, including U.S.
Government Securities, can change in value as a result of changes in interest
rates, the issuer's actual or perceived creditworthiness or the issuer's ability
to meet its obligations.
 
   
TYPES OF INVESTMENTS
    
 
JANUS MONEY MARKET FUND
Janus Money Market Fund pursues its objective by investing primarily in high
quality debt obligations and obligations of financial institutions. The Fund may
also invest in U.S. Government Securities (as defined below) and municipal
securities, although the Fund expects to invest in such securities to a lesser
degree.
 
DEBT OBLIGATIONS
The Fund may invest in debt obligations of domestic issuers, including
commercial paper (short-term promissory notes issued by companies to finance
their, or their affiliates', current obligations), notes and bonds, and variable
amount master demand notes. The payment obligations on these instruments may be
backed by securities, swap agreements or other assets, by the guarantee of a
third party or solely by the unsecured promise of the issuer to make payments
when due. The Fund may invest in privately issued commercial paper or other
securities that are restricted as to disposition under the federal securities
laws. In general, sales of these securities may not be made absent registration
under the Securities Act of 1933 (the "1933 Act") or the availability of an
appropriate exemption. Pursuant to Section 4(2) of the 1933 Act or Rule 144A
adopted under the 1933 Act, however, some of these securities are eligible for
resale to institutional investors, and accordingly, Janus Capital may determine
that a liquid market exists for such a security pursuant to guidelines adopted
by the Trustees.
 
OBLIGATIONS OF FINANCIAL INSTITUTIONS
   
The Fund may invest in obligations of financial institutions. Examples of
obligations in which the Fund may invest include negotiable certificates of
deposit, bankers' acceptances, time deposits and other obligations of U.S. banks
(including savings and loan associations) having total assets in excess of one
billion dollars and U.S. branches of
    
 
   
JANUS MONEY MARKET FUNDS - SERVICE SHARES PROSPECTUS      FEBRUARY 17, 1998    7
    
<PAGE>   
 
   
foreign banks having total assets in excess of ten billion dollars. The Fund may
also invest in Eurodollar and Yankee bank obligations as discussed below and
other U.S. dollar-denominated obligations of foreign banks having total assets
in excess of ten billion dollars that Janus Capital believes are of an
investment quality comparable to obligations of U.S. banks in which the Fund may
invest.
    
 
Certificates of deposit represent an institution's obligation to repay funds
deposited with it that earn a specified interest rate over a given period.
Bankers' acceptances are negotiable obligations of a bank to pay a draft which
has been drawn by a customer and are usually backed by goods in international
trade. Time deposits are non-negotiable deposits with a banking institution that
earn a specified interest rate over a given period. Fixed time deposits, which
are payable at a stated maturity date and bear a fixed rate of interest,
generally may be withdrawn on demand by the Fund but may be subject to early
withdrawal penalties that could reduce the Fund's yield. Unless there is a
readily available market for them, time deposits that are subject to early
withdrawal penalties and that mature in more than seven days will be treated as
illiquid securities.
 
   
Eurodollar bank obligations are dollar-denominated certificates of deposit or
time deposits issued outside the U.S. capital markets by foreign branches of
U.S. banks and by foreign banks. Yankee bank obligations are dollar-denominated
obligations issued in the U.S. capital markets by foreign banks.
    
 
   
Foreign, Eurodollar (and to a limited extent, Yankee) bank obligations are
subject to certain sovereign risks. One such risk is the possibility that a
foreign government might prevent dollar-denominated funds from flowing across
its borders. Other risks include: adverse political and economic developments in
a foreign country; the extent and quality of government regulation of financial
markets and institutions; the imposition of foreign withholding taxes; and
expropriation or nationalization of foreign issuers.
    
 
U.S. GOVERNMENT SECURITIES
The Fund may invest without limit in U.S. Government Securities as described
below under "Janus Government Money Market Fund."
 
MUNICIPAL SECURITIES
The Fund may invest in obligations of states, territories or possessions of the
United States and their subdivisions, authorities and corporations as described
below under "Janus Tax-Exempt Money Market Fund." These obligations may pay
interest that is exempt from federal income taxation.
 
JANUS GOVERNMENT MONEY MARKET FUND
Janus Government Money Market Fund pursues its objective by investing
exclusively in obligations issued and/or guaranteed as to principal and interest
by the United States government or by its agencies and instrumentalities and
repurchase agreements secured by such obligations.
 
U.S. GOVERNMENT SECURITIES
U.S. Government Securities shall have the meaning set forth in the 1940 Act. The
1940 Act defines U.S. Government Securities to include securities issued or
guaranteed by the U.S. government, its agencies and instrumentalities. U.S.
Government Securities may also include repurchase agreements collateralized by
and municipal securities escrowed
 
   
 8   JANUS MONEY MARKET FUNDS - SERVICE SHARES PROSPECTUS      FEBRUARY 17, 1998
    
<PAGE>   
 
with or refunded with U.S. government securities. U.S. Government Securities in
which the Fund may invest include U.S. Treasury securities and obligations
issued or guaranteed by U.S. government agencies and instrumentalities that are
backed by the full faith and credit of the U.S. government, such as those
guaranteed by the Small Business Administration or issued by the Government
National Mortgage Association. In addition, U.S. Government Securities in which
the Fund may invest include securities supported primarily or solely by the
creditworthiness of the issuer, such as securities of the Federal National
Mortgage Association, the Federal Home Loan Mortgage Corporation and the
Tennessee Valley Authority. There is no guarantee that the U.S. government will
support securities not backed by its full faith and credit. Accordingly,
although these securities have historically involved little risk of loss of
principal if held to maturity, they may involve more risk than securities backed
by the full faith and credit of the U.S. government.
 
JANUS TAX-EXEMPT MONEY MARKET FUND
Janus Tax-Exempt Money Market Fund pursues its objective by investing primarily
in municipal securities whose interest is exempt from federal income taxes,
including the federal alternative minimum tax. Although the Fund will attempt to
invest substantially all of its assets in municipal securities whose interest is
exempt from federal income taxes, the Fund reserves the right to invest up to
20% of its net assets in securities whose interest is federally taxable.
Additionally, when its portfolio manager is unable to locate investment
opportunities with desirable risk/reward characteristics, the Fund may invest
without limit in cash and cash equivalents, including obligations that may be
federally taxable (see "Taxable Investments").
 
MUNICIPAL SECURITIES
The municipal securities in which the Fund may invest include municipal notes
and short-term municipal bonds. Municipal notes are generally used to provide
for the issuer's short-term capital needs and generally have maturities of 397
days or less. Examples include tax anticipation and revenue anticipation notes,
which generally are issued in anticipation of various seasonal revenues, bond
anticipation notes, construction loan notes and tax-exempt commercial paper.
Short-term municipal bonds may include "general obligation bonds," which are
secured by the issuer's pledge of its faith, credit and taxing power for payment
of principal and interest; "revenue bonds," which are generally paid from the
revenues of a particular facility or a specific excise tax or other source; and
"industrial development bonds," which are issued by or on behalf of public
authorities to provide funding for various privately operated industrial and
commercial facilities. The Fund may also invest in high quality participation
interests in municipal securities. A more detailed description of various types
of municipal securities is contained in Appendix B in the SAI.
 
When the assets and revenues of an agency, authority, instrumentality or other
political subdivision are separate from those of the government creating the
issuing entity and a security is backed only by the assets and revenues of the
issuing entity, that entity will be deemed to be the sole issuer of the
security. Similarly, in the case of an industrial development bond backed only
by the assets and revenues of the non-governmental issuer, the non-governmental
issuer will be deemed to be the sole issuer of the bond.
 
   
JANUS MONEY MARKET FUNDS - SERVICE SHARES PROSPECTUS      FEBRUARY 17, 1998    9
    
<PAGE>   
 
At times, the Fund may invest more than 25% of its total assets in tax-exempt
securities that are related in such a way that an economic, business, or
political development or change affecting one such security could similarly
affect the other securities; for example, securities whose issuers are located
in the same state, or securities whose interest is derived from revenues of
similar type projects. The Fund may also invest more than 25% of its assets in
industrial development bonds or participation interests therein.
 
Yields on municipal securities are dependent on a variety of factors, including
the general conditions of the money market and of the municipal bond and
municipal note markets, the size of a particular offering, the maturity of the
obligation and the rating of the issue. The achievement of the Fund's investment
objective is dependent in part on the continuing ability of the issuers of
municipal securities in which the Fund invests to meet their obligations for the
payment of principal and interest when due. Obligations of issuers of municipal
securities are subject to the provisions of bankruptcy, insolvency and other
laws affecting the rights and remedies of creditors, such as the Bankruptcy
Reform Act of 1978, as amended. Therefore, the possibility exists that, as a
result of litigation or other conditions, the ability of any issuer to pay, when
due, the principal of and interest on its municipal securities may be materially
affected.
 
MUNICIPAL LEASES
The Fund may invest in municipal leases or participation interests therein.
Municipal leases are municipal securities which may take the form of a lease or
an installment purchase or conditional sales contract. Municipal leases are
issued by state and local governments and authorities to acquire a wide variety
of equipment and facilities. Lease obligations may not be backed by the issuing
municipality's credit and may involve risks not normally associated with general
obligation bonds and other revenue bonds. For example, their interest may become
taxable if the lease is assigned and the holders may incur losses if the issuer
does not appropriate funds for the lease payment on an annual basis, which may
result in termination of the lease and possible default. Janus Capital may
determine that a liquid market exists for municipal lease obligations pursuant
to guidelines established by the Trustees.
 
TAXABLE INVESTMENTS
As discussed above, although the Fund will attempt to invest substantially all
of its assets in municipal securities whose interest is exempt from federal
income tax, the Fund may under certain circumstances invest in certain
securities whose interest is subject to such taxation. These securities include:
(i) short-term obligations of the U.S. government, its agencies or
instrumentalities, (ii) certificates of deposit, bankers' acceptances and
interest-bearing savings deposits of banks having total assets of more than one
billion dollars and whose deposits are insured by the Federal Deposit Insurance
Corporation, (iii) commercial paper and (iv) repurchase agreements as described
below covering any of the securities described in items (i)-(iii) above or any
other obligations of the U.S. government, its agencies or instrumentalities.
 
   
 10   JANUS MONEY MARKET FUNDS - SERVICE SHARES PROSPECTUS     FEBRUARY 17, 1998
    
<PAGE>   
 
COMMON INVESTMENT TECHNIQUES
PARTICIPATION INTERESTS
The Funds may invest in participation interests in any type of security in which
the Funds may invest. A participation interest gives a Fund an undivided
interest in the underlying securities in the proportion that the Fund's
participation interest bears to the total principal amount of the underlying
securities. Participation interests usually carry a demand feature, as described
below, backed by a letter of credit or guarantee of the institution that issued
the interests permitting the holder to tender them back to the institution.
 
DEMAND FEATURES
The Funds may invest in securities that are subject to puts and stand-by
commitments ("demand features"). Demand features give the Fund the right to
resell securities at specified periods prior to their maturity dates to the
seller or to some third party at an agreed-upon price or yield. Securities with
demand features may involve certain expenses and risks, including the inability
of the issuer of the instrument to pay for the securities at the time the
instrument is exercised, non-marketability of the instrument and differences
between the maturity of the underlying security and the maturity of the
instrument. Securities may cost more with demand features than without them.
Demand features can serve three purposes: to shorten the maturity of a variable
or floating rate security, to enhance the instrument's credit quality and to
provide a source of liquidity. Demand features are often issued by third party
financial institutions, generally domestic and foreign banks. Accordingly, the
credit quality and liquidity of the Funds' investments may be dependent in part
on the credit quality of the banks supporting the Funds' investments. This will
result in exposure to risks pertaining to the banking industry, including the
foreign banking industry. Brokerage firms and insurance companies also provide
certain liquidity and credit support. A substantial portion of the Janus Tax-
Exempt Money Market Fund's portfolio in particular may consist of securities
backed by banks and other financial institutions, and thus adverse changes in
the credit quality of these institutions could cause losses to the Fund and
affect its share price.
 
VARIABLE AND FLOATING RATE SECURITIES
The securities in which the Funds invest may have variable or floating rates of
interest. These securities pay interest at rates that are adjusted periodically
according to a specified formula, usually with reference to some interest rate
index or market interest rate. Securities with ultimate maturities of greater
than 397 days may be purchased only pursuant to Rule 2a-7. Under that Rule, only
those long-term instruments that have demand features which comply with certain
requirements and certain variable rate U.S. Government Securities may be
purchased. Similar to fixed rate debt instruments, variable and floating rate
instruments are subject to changes in value based on changes in market interest
rates or changes in the issuer's or guarantor's creditworthiness. The rate of
interest on securities purchased by a Fund may be tied to short-term Treasury or
other government securities or indices on securities that are permissible
investments of the Funds, as well as other money market rates of interest. The
Funds will not purchase securities whose values are tied to interest rates or
indices that are not appropriate for the duration and volatility standards of a
money market fund.
 
   
JANUS MONEY MARKET FUNDS - SERVICE SHARES PROSPECTUS     FEBRUARY 17, 1998    11
    
<PAGE>   
 
MORTGAGE- AND ASSET-BACKED SECURITIES
Janus Money Market Fund and Janus Government Money Market Fund may purchase
fixed or adjustable rate mortgage-backed securities issued by the Government
National Mortgage Association, Federal National Mortgage Association, the
Federal Home Loan Mortgage Corporation, or other governmental or
government-related entities. In addition, Janus Money Market Fund may purchase
other asset-backed securities, including securities backed by automobile loans,
equipment leases or credit card receivables. These securities directly or
indirectly represent a participation in, or are secured by and payable from,
fixed or adjustable rate mortgage or other loans which may be secured by real
estate or other assets. Unlike traditional debt instruments, payments on these
securities include both interest and a partial payment of principal. Prepayments
of the principal of underlying loans may shorten the effective maturities of
these securities and may result in a Fund having to reinvest proceeds at a lower
interest rate.
 
REPURCHASE AGREEMENTS
Each Fund may seek additional income by entering into collateralized repurchase
agreements. Repurchase agreements are transactions in which a Fund purchases
securities and simultaneously commits to resell those securities to the seller
at an agreed-upon price on an agreed-upon future date. The resale price reflects
a market rate of interest that is not related to the coupon rate or maturity of
the purchased securities. If the seller of the securities underlying a
repurchase agreement fails to pay the agreed resale price on the agreed delivery
date, a Fund may incur costs in disposing of the collateral and may experience
losses if there is any delay in its ability to do so.
 
REVERSE REPURCHASE AGREEMENTS
Each Fund may enter into reverse repurchase agreements. Reverse repurchase
agreements are transactions in which a Fund sells a security and simultaneously
commits to repurchase that security from the buyer at an agreed upon price on an
agreed upon future date. This technique will be used primarily for temporary or
emergency purposes, such as meeting redemption requests.
 
DELAYED DELIVERY SECURITIES
Each Fund may purchase securities on a when-issued or delayed delivery basis.
Securities so purchased are subject to market price fluctuation from the time of
purchase but no interest on the securities accrues to a Fund until delivery and
payment for the securities take place. Accordingly, the value of the securities
on the delivery date may be more or less than the purchase price. Forward
commitments will be entered into only when a Fund has the intention of taking
possession of the securities, but a Fund may sell the securities before the
settlement date if deemed advisable.
 
BORROWING AND LENDING
   
Each Fund may borrow money for temporary or emergency purposes in amounts up to
25% of its total assets. A Fund may not mortgage or pledge securities except to
secure permitted borrowings. As a fundamental policy, a Fund will not lend
securities or other assets if, as a result, more than 25% of its total assets
would be lent to other parties. The Funds do not currently intend to engage in
securities lending; however, under the terms of an exemptive order received from
the SEC, each of the Funds may borrow
    
 
   
 12   JANUS MONEY MARKET FUNDS - SERVICE SHARES PROSPECTUS     FEBRUARY 17, 1998
    
<PAGE>   
 
money from or lend money to other funds that permit such transactions and are
advised by Janus Capital. There is no assurance that such permission will be
granted.
 
                             INVESTMENT ADVISER AND
                                 ADMINISTRATOR
 
INVESTMENT ADVISER
Each Fund has a separate Investment Advisory Agreement with Janus Capital, 100
Fillmore Street, Denver, Colorado 80206-4923. Janus Capital has served as
investment adviser to Janus Fund since 1970 and currently serves as investment
adviser to all of the Janus funds, as well as adviser or subadviser to other
mutual funds and individual, corporate, charitable and retirement accounts.
Kansas City Southern Industries, Inc., a publicly traded holding company whose
primary subsidiaries are engaged in transportation, information processing and
financial services ("KCSI"), owns approximately 83% of the outstanding voting
stock of Janus Capital. Thomas H. Bailey, the President and Chairman of the
Board of Janus Capital, owns approximately 12% of its voting stock and, by
agreement with KCSI, selects a majority of Janus Capital's Board.
 
Pursuant to the Investment Advisory Agreements, Janus Capital furnishes
continuous advice and recommendations concerning each Fund's investments. Each
of the Funds has agreed to compensate Janus Capital for its advisory services by
the monthly payment of a fee at the annual rate of 0.20% of the value of the
average daily net assets of each Fund. Janus Capital has agreed to waive a
portion of its fee and accordingly, the advisory fee of each Fund will be
calculated at the annual rate of 0.10% of the value of each Fund's average daily
net assets. Janus Capital may modify or terminate the waiver at any time upon at
least 90 days' notice to the Trustees.
 
ADMINISTRATOR
Each of the Funds has also entered into an Administration Agreement with Janus
Capital, pursuant to which Janus Capital furnishes certain administrative,
compliance and accounting services for the Funds, pays the costs of printing
reports and prospectuses for existing shareholders, provides office space for
the Funds and pays the salaries, fees and expenses of all Fund officers and of
those Trustees who are affiliated with Janus Capital. Administrative services
provided by Janus Capital under the Administration Agreements include custody
and transfer agency services. Janus Capital is paid an administration fee,
calculated daily and paid monthly, at the annual rate of 0.40% of the value of
the average daily net assets of each Fund attributable to Shares for services
rendered pursuant to the Administration Agreements. Janus Capital has agreed to
waive a portion of its fee and accordingly, the administration fee paid by the
Shares will be calculated at the annual rate of 0.30% of the value of each
Fund's average daily net assets attributable to the Shares. Janus Capital may
modify or terminate this waiver at any time upon at least 90 days' notice to the
Trustees.
 
Each Fund pays all of its expenses not assumed by Janus Capital, including
auditing fees and independent Trustees' fees and expenses.
 
   
JANUS MONEY MARKET FUNDS - SERVICE SHARES PROSPECTUS     FEBRUARY 17, 1998    13
    
<PAGE>   
 
Janus Capital may use all or a portion of its administration fee to compensate
Financial Institutions for providing administrative services to their customers
who invest in the Shares. The types of services that the Financial Institutions
would provide include serving as the sole shareholder of record, shareholder
recordkeeping, processing and aggregating purchase and redemption transactions,
providing periodic statements, forwarding shareholder reports and other
materials, providing tax information, and providing other similar services that
the Funds would have to perform if they were dealing directly with the
beneficial owners, rather than the Financial Institutions, as shareholders of
record.
 
The Glass-Steagall Act prohibits a depository institution (such as a commercial
bank or a savings and loan association) from being an underwriter or distributor
of most securities. In the event the Glass-Steagall Act is deemed to prohibit
depository institutions from acting in the administrative capacities described
above or should Congress relax current restrictions on depository institutions,
the Trustees will consider appropriate changes in the services.
 
PORTFOLIO TRANSACTIONS
Purchases and sales of securities on behalf of each Fund are executed by brokers
and dealers selected by Janus Capital. Broker-dealers are selected on the basis
of their ability to obtain best price and execution for the Funds' transactions
and recognizing brokerage, research and other services provided to the Fund and
to Janus Capital. Janus Capital may also consider payments made by brokers
effecting transactions for a Fund (i) to the Fund or (ii) to other persons on
behalf of the Fund for services provided to the Fund for which it would be
obligated to pay. The Funds' Trustees have also authorized the Funds to place
portfolio transactions on an agency basis with a broker-dealer that is
affiliated with Janus Capital. Agency trades, if any, that are placed with such
affiliated party serve to reduce certain expenses of the Funds. The SAI further
explains the selection of broker-dealers.
 
PERSONAL INVESTING
Janus Capital does not permit portfolio managers to purchase and sell securities
for their own accounts, except under the limited exceptions contained in Janus
Capital's policy governing personal investing. Janus Capital's policy requires
investment and other personnel to conduct their personal investment activities
in a manner that Janus Capital believes is not detrimental to the Funds and
Janus Capital's other advisory clients. See the SAI for more detailed
information.
 
   
YEAR 2000
    
   
Many computer systems use six-digit fields to store dates. With the approach of
the year 2000, these fields must be converted to eight-digit fields in order to
recognize the difference between 1900 and 2000. Failure to adequately address
this issue could have potentially serious repercussions. Preparing for Year 2000
is a high priority for Janus Capital, which has established a dedicated group to
address this issue and has entered into a consulting arrangement with one of the
foremost experts in Year 2000 compliance to assess systems implications for
Janus Capital. Janus Capital does not
    
 
   
 14   JANUS MONEY MARKET FUNDS - SERVICE SHARES PROSPECTUS     FEBRUARY 17, 1998
    
<PAGE>   
 
   
anticipate that the move to Year 2000 will have a material impact on its ability
to continue to provide the Funds with service at current levels.
    
 
                            DISTRIBUTIONS AND TAXES
 
Dividends representing substantially all of the net investment income and any
net realized gains on sales of securities are declared daily, Saturdays, Sundays
and holidays included, and distributed on the last business day of each month.
If a month begins on a Saturday, Sunday or holiday, dividends for those days are
declared at the end of the preceding month and distributed on the first business
day of the month. Distributions will be reinvested in Shares of a Fund unless
otherwise elected by the shareholder pursuant to the options offered by the
Financial Institution.
 
Distributions for all of the Funds (except Janus Tax-Exempt Money Market Fund)
are taxable income and are subject to federal income tax (except for
shareholders exempt from income tax), whether such distributions are received in
cash or are reinvested in additional Shares. Full information regarding the tax
status of income dividends and any capital gains distributions will be mailed to
Financial Institutions who will forward the information to their customers for
tax purposes on or before January 31st of each year. Because the Funds are money
market funds, they do not anticipate making any capital gains distributions.
 
Janus Tax-Exempt Money Market Fund anticipates that substantially all income
dividends it pays will be exempt from federal income tax. However, dividends
attributable to interest on taxable investments, together with distributions
from any net realized capital gains, are taxable. In addition, interest on
certain private activity bonds is a preference item for purposes of the
individual and corporate alternative minimum taxes. To the extent that the Fund
earns such income, shareholders who are subject to the alternative minimum tax
must include such income as a preference item. The Fund will advise shareholders
of the percentage of dividends, if any, subject to the alternative minimum tax.
 
Dividends and capital gains distributions may also be subject to state and local
taxes. In certain states some portion of dividends and distributions (depending
on the sources of the Fund's net income) of Janus Tax-Exempt Money Market Fund
may be exempt from state and local taxes. Shareholders should consult their own
tax advisor regarding exemption from any applicable state and local tax, as well
as the tax treatment of any dividends or distributions from the Shares.
 
The Funds intend to comply with provisions of the Internal Revenue Code
applicable to investment companies, and thus it is not expected that any of the
Funds will be required to pay any federal income or excise taxes. The SAI
further explains the Funds' tax status.
 
   
JANUS MONEY MARKET FUNDS - SERVICE SHARES PROSPECTUS     FEBRUARY 17, 1998    15
    
<PAGE>   
 
                                  PERFORMANCE
 
The Shares may measure performance in several ways, including "yield,"
"effective yield," and "tax equivalent yield" (for Janus Tax-Exempt Money Market
Fund only). Yield is a way of showing the rate of income the Shares earn on
investments as a percentage of the Share price. Yield represents the income,
less expenses generated by an investment, in the Shares over a seven-day period
expressed as an annual percentage rate. Effective yield is similar in that it is
calculated over the same time frame, but instead the net investment income is
compounded and then annualized. Due to the compounding effect, the effective
yield will normally be higher than the yield.
 
Shares of Janus Tax-Exempt Money Market Fund may also quote tax-equivalent
yield, which shows the taxable yield an investor would have to earn before taxes
to equal such Shares' tax-free yield. A tax-equivalent yield is calculated by
dividing such Shares' tax-exempt yield by the result of one minus a stated
federal tax rate. Only that portion of the Fund's income that is tax-exempt is
adjusted in this calculation.
 
Performance figures are based upon historical results and are not intended to
indicate future performance.
 
                           MISCELLANEOUS INFORMATION
 
ORGANIZATION
Each Fund is an open-end management investment company registered under the 1940
Act as a series of the Trust, which was created on February 11, 1986. Each Fund
currently offers three classes of shares by separate prospectuses. The Shares
offered by this Prospectus are available only through Financial Institutions
that meet minimum investment requirements in connection with trust accounts,
cash management programs and similar programs provided to their customers. A
second class of shares, Institutional Shares of each Fund, are available only to
institutional clients, including corporations, foundations and trusts, and
individuals meeting certain initial investment requirements. A third class of
shares, Investor Shares of each Fund, are available to the general public.
Because the expenses of each class may differ, the performance of each class is
expected to differ. If you would like additional information, please call
1-800-29JANUS.
 
TRUSTEES
The Trustees oversee the business affairs of the Trust and are responsible for
major decisions relating to each Fund's investment objective and policies. The
Trustees delegate the day-to-day management of the Funds to the officers of the
Trust and meet at least quarterly to review the Funds' investment policies,
performance, expenses and other business affairs.
 
VOTING RIGHTS
The Trust is not required to hold annual shareholder meetings. However, special
meetings may be called for a specific class of shares, a specific Fund, or for
the Trust as a whole, for purposes such as electing or removing Trustees,
terminating or reorganizing
 
   
 16   JANUS MONEY MARKET FUNDS - SERVICE SHARES PROSPECTUS     FEBRUARY 17, 1998
    
<PAGE>   
 
the Trust, changing fundamental policies or voting on matters when required by
the 1940 Act. Separate votes are taken by a separate Fund (or a separate class
of shares) only if a matter affects or requires the vote of just that Fund (or
those shares). Shareholders are entitled to cast one vote for each Share they
own.
 
CUSTODIAN, TRANSFER AGENT AND DISTRIBUTOR
   
UMB Bank, N.A., P.O. Box 419226, Kansas City, Missouri 64141-6226, is the
custodian of the Funds' assets. The custodian holds each Fund's assets in
safekeeping and collects and remits the income thereon subject to the
instructions of each Fund.
    
 
Janus Service Corporation, P.O. Box 173375, Denver, Colorado 80217-3375, a
wholly-owned subsidiary of Janus Capital, provides transfer agency and
shareholder services for the Funds.
 
Janus Distributors, Inc., 100 Fillmore Street, Denver, Colorado 80206-4928, a
wholly-owned subsidiary of Janus Capital, is a distributor of the Shares.
 
   
JANUS MONEY MARKET FUNDS - SERVICE SHARES PROSPECTUS     FEBRUARY 17, 1998    17
    
<PAGE>   
 
                              SHAREHOLDER'S GUIDE
 
INVESTORS MAY NOT PURCHASE OR REDEEM SHARES OF THE FUNDS DIRECTLY. SHARES MAY BE
PURCHASED OR REDEEMED ONLY THROUGH FINANCIAL INSTITUTIONS IN CONNECTION WITH
TRUST ACCOUNTS, CASH MANAGEMENT PROGRAMS AND SIMILAR PROGRAMS. YOUR FINANCIAL
INSTITUTION WILL PROVIDE YOU WITH INSTRUCTIONS ON PURCHASING OR REDEEMING
SHARES.
 
The Financial Institutions are responsible for promptly transmitting purchase,
redemption and other requests to the Funds under the arrangements made between
the Financial Institutions and their customers. The Funds are not responsible
for the failure of any Financial Institution to carry out its obligations to its
customers.
 
PURCHASES
   
Purchases of Fund Shares may be made only through omnibus accounts of Financial
Institutions in connection with trust accounts, cash management programs and
similar programs. Your Financial Institution will provide you with instructions
on purchasing Shares. The following information applies to purchase orders from
Financial Institutions to Janus (Check with your Financial Institution directly
for deadlines for purchase orders from you to your Financial Institution).
Requests to purchase Janus Money Market Fund and Janus Government Money Market
Fund received from a Financial Institution before 3:00 p.m. (New York time) on a
business day will receive dividends declared on the purchase date. Requests to
purchase Janus Tax-Exempt Money Market Fund must be received from a Financial
Institution before 12:00 p.m. (New York time) on a business day in order to
receive the dividend declared on the day of purchase. In addition, the Funds'
transfer agent must receive payment from the Financial Institution in federal
funds by 6:00 p.m. (New York time). The Funds also reserve the right to require
purchase requests and payments from the Financial Institution prior to these
times on days when the bond market closes before 4:00 p.m. (New York time).
Purchase orders received after these times will receive the dividend declared
the following day.
    
 
The Financial Institutions may impose charges and restrictions different from
those imposed by the Funds. The Financial Institutions may also require
different minimum initial and subsequent investments than required by the Funds.
 
   
Each Fund reserves the right to reject any specific purchase order. Purchase
orders may be refused if, in Janus Capital's opinion, they are of a size that
would disrupt the management of a Fund. Any Fund may discontinue sales of its
Shares if management believes that a substantial further increase may adversely
affect that Fund's ability to achieve its investment objective. In such event,
however, it is anticipated that existing Financial Institution customers in that
Fund would be permitted to continue to authorize investment in such Fund and to
reinvest any dividends or capital gains distributions.
    
 
MINIMUM INVESTMENT
There is a $250,000 initial aggregate investment minimum by each Financial
Institution. The Funds may, in their discretion, waive this minimum under
certain circumstances but, in such event, the minimum must be reached within 90
days of opening the
 
   
 18   JANUS MONEY MARKET FUNDS - SERVICE SHARES PROSPECTUS     FEBRUARY 17, 1998
    
<PAGE>   
 
account. Financial Institutions who do not maintain the $250,000 minimum will be
given the option of requesting their customers to exchange into Investor Shares
if the required minimum investment for Investor Shares is met or having their
customers' Shares redeemed.
 
NET ASSET VALUE
The net asset value ("NAV") of the Shares is determined at the close of the
regular trading session of the New York Stock Exchange (normally 4:00 p.m., New
York time) each day that both the Exchange and the New York Federal Reserve Bank
are open. NAV per share is determined by dividing the total value of the
securities and other assets, less liabilities, by the total number of Shares
outstanding. Portfolio securities are valued at their amortized cost. Amortized
cost valuation involves valuing an instrument at its cost and thereafter
assuming a constant amortization to maturity (or such other date as permitted by
Rule 2a-7) of any discount or premium. If fluctuating interest rates cause the
market value of a portfolio to deviate more than 1/2 of 1% from the value
determined on the basis of amortized cost, the Trustees will consider whether
any action, such as adjusting the Share's NAV to reflect current market
conditions, should be initiated to prevent any material dilutive effect on
shareholders.
 
SHARE CERTIFICATES
Share certificates are not available for the Shares in order to maintain the
general liquidity that is representative of a money market fund and to help
facilitate transactions in shareholder accounts.
 
REDEMPTIONS
   
Redemptions, like purchases, may be effected only through the accounts of
participating Financial Institutions. Your Financial Institution will provide
you with instructions on redeeming shares. The following information applies to
redemption orders from Financial Institutions to Janus (Check with your
Financial Institution directly for deadlines for redemption orders from you to
your Financial Institution). If a request for a redemption is received from a
Financial Institution by 3:00 p.m. (New York time) for Janus Money Market Fund
and Janus Government Money Market Fund and by 12:00 p.m. (New York time) for
Janus Tax-Exempt Money Market Fund. Shares will be redeemed and the redemption
amount wired in federal funds to the Financial Institution's omnibus account
that day. After 3:00 p.m. (12:00 p.m. for Janus Tax Exempt Money Market Fund), a
redemption request will be processed at that day's NAV and will include that
day's dividends, but generally will not be wired until the next bank business
day. The Funds reserve the right to require redemption requests prior to these
times on days when the bond market closes before 4:00 p.m. (New York time).
    
 
   
Shares of any Fund may be redeemed on any business day.
    
 
SHAREHOLDER COMMUNICATIONS
Shareholders will receive annual and semiannual reports including the financial
statements of the Funds that they have authorized for investment from their
Financial Institution. Each report will show the investments owned by each Fund
and the market values thereof, as well as other information about the Funds and
their operations. The Trust's fiscal year ends October 31.
 
   
JANUS MONEY MARKET FUNDS - SERVICE SHARES PROSPECTUS     FEBRUARY 17, 1998    19
    

<PAGE>   
 
                             JANUS INVESTMENT FUND
 
                              100 Fillmore Street
                             Denver, CO 80206-4928
                                 (800) 525-3713
 
                      STATEMENT OF ADDITIONAL INFORMATION
   
                               FEBRUARY 17, 1998
    
 
                                  GROWTH FUNDS
                                   Janus Fund
                             Janus Enterprise Fund
                               Janus Mercury Fund
                               Janus Olympus Fund
                              Janus Overseas Fund
   
                         Janus Special Situations Fund
    
                               Janus Twenty Fund
                              Janus Worldwide Fund
 
                               COMBINATION FUNDS
                              Janus Balanced Fund
                            Janus Equity Income Fund
                          Janus Growth and Income Fund
                               FIXED-INCOME FUNDS
                           Janus Flexible Income Fund
                             Janus High-Yield Fund
                         Janus Federal Tax-Exempt Fund
                           Janus Short-Term Bond Fund
 
     This Statement of Additional Information ("SAI") pertains to the funds
listed above, each of which is a separate series of Janus Investment Fund, a
Massachusetts business trust (the "Trust"). Each of these series of the Trust
represents shares of beneficial interest in a separate portfolio of securities
and other assets with its own objective and policies (individually, a "Fund" and
collectively, the "Funds"). Each Fund is managed separately by Janus Capital
Corporation ("Janus Capital").
 
   
     This SAI is not a Prospectus and should be read in conjunction with the
Funds' Prospectuses dated February 17, 1998, which are incorporated by reference
into this SAI and may be obtained from the Trust at the above phone number or
address. This SAI contains additional and more detailed information about the
Funds' operations and activities than the Prospectuses.
    
 
                                  [JANUS LOGO]
<PAGE>   
 
                             JANUS INVESTMENT FUND
                      STATEMENT OF ADDITIONAL INFORMATION
                               TABLE OF CONTENTS
Investment Policies, Restrictions and Techniques.............................. 3
     Investment Objectives.................................................... 3
     Portfolio Policies....................................................... 4
   
     Investment Restrictions Applicable to All Funds.......................... 5
    
   
     Investment Policies Applicable to Certain Funds.......................... 8
    
   
Types of Securities and Investment Techniques................................. 8
    
   
     Illiquid Investments..................................................... 8
    
   
     Zero Coupon, Pay-In-Kind and Step Coupon Securities...................... 9
    
   
     Pass-Through Securities.................................................. 9
    
   
     Investment Company Securities........................................... 11
    
   
     Depositary Receipts..................................................... 11
    
   
     Municipal Obligations................................................... 11
    
   
     Other Income-Producing Securities....................................... 12
    
   
     Repurchase and Reverse Repurchase Agreements............................ 12
    
   
     High-Yield/High-Risk Securities......................................... 13
    
   
     Futures, Options and Other Derivative Instruments....................... 14
    
   
Investment Adviser........................................................... 26
    
   
Custodian, Transfer Agent and Certain Affiliations........................... 29
    
   
Portfolio Transactions and Brokerage......................................... 30
    
   
Officers and Trustees........................................................ 34
    
   
Purchase of Shares........................................................... 38
    
   
     Net Asset Value Determination........................................... 38
    
   
     Reinvestment of Dividends and Distributions............................. 39
    
   
Redemption of Shares......................................................... 40
    
   
Shareholder Accounts......................................................... 40
    
   
     Telephone Transactions.................................................. 40
    
   
     Systematic Redemptions.................................................. 40
    
   
Tax-Deferred Accounts........................................................ 41
    
   
Income Dividends, Capital Gains Distributions and Tax Status................. 42
    
   
Principal Shareholders....................................................... 42
    
   
Miscellaneous Information.................................................... 42
    
   
     Shares of the Trust..................................................... 43
    
   
     Voting Rights........................................................... 44
    
   
     Independent Accountants................................................. 44
    
   
     Registration Statement.................................................. 44
    
   
Performance Information...................................................... 44
    
   
Financial Statements......................................................... 47
    
   
Appendix A................................................................... 48
    
   
     Explanation of Rating Categories........................................ 48
    
- --------------------------------------------------------------------------------
 
                                        2
<PAGE>   
 
                              INVESTMENT POLICIES,
                          RESTRICTIONS AND TECHNIQUES
 
   
     Each Fund's investment objective is discussed in the Prospectus and
summarized below. There is no assurance that any Fund will achieve its
respective objective. The investment objectives of the Funds are not fundamental
and may be changed by the Trustees without shareholder approval.
    
 
INVESTMENT OBJECTIVES
   
     JANUS FUND is a diversified fund that seeks long-term growth of capital in
a manner consistent with the preservation of capital by investing primarily in
common stocks of issuers of any size. Generally, this Fund emphasizes issuers
with larger market capitalizations.
    
 
     JANUS ENTERPRISE FUND is a nondiversified fund that seeks long-term growth
of capital by investing primarily in common stocks. The Fund intends to normally
invest at least 50% of its equity assets in securities issued by medium-sized
companies (as defined in the Prospectus).
 
   
     JANUS MERCURY FUND is a diversified fund that seeks long-term growth of
capital by investing primarily in common stocks of issuers of any size,
including larger, well-established companies and/or smaller, emerging growth
companies.
    
 
     JANUS OLYMPUS FUND is a nondiversified fund that seeks long-term growth of
capital by investing primarily in common stocks of issuers of any size,
including larger, well-established companies and/or smaller, emerging growth
companies.
 
     JANUS OVERSEAS FUND is a diversified fund that seeks long-term growth of
capital by investing primarily in common stocks of foreign issuers of any size.
The Fund normally invests at least 65% of its total assets in issuers from at
least five different countries excluding the United States.
 
   
     JANUS SPECIAL SITUATIONS FUND is a nondiversified fund that seeks capital
appreciation by investing primarily in common stocks of domestic and foreign
issuers. The Fund seeks investments in issuers that its portfolio manager
believes have been overlooked or undervalued by other investors.
    
 
     JANUS TWENTY FUND is a nondiversified fund that seeks long-term growth of
capital. Under normal conditions, this Fund concentrates its investments in a
core position of 20-30 common stocks.
 
   
     JANUS WORLDWIDE FUND is a diversified fund that seeks long-term growth of
capital in a manner consistent with the preservation of capital by investing
primarily in common stocks of foreign and domestic issuers of any size. Janus
Worldwide Fund normally invests in issuers from at least five different
countries including the United States.
    
 
     JANUS BALANCED FUND is a diversified fund that seeks long-term capital
growth, consistent with preservation of capital and balanced by current income.
Janus Balanced Fund normally invests 40-60% of its assets in securities selected
primarily for growth potential and 40-60% of its assets in securities selected
for their income potential.
 
                                        3
<PAGE>   
 
     JANUS EQUITY INCOME FUND is a diversified fund that seeks current income
and long-term growth of capital by investing primarily in income-producing
equity securities.
 
   
     JANUS GROWTH AND INCOME FUND is a diversified fund that seeks both long-
term capital growth and current income. Janus Growth and Income Fund places a
stronger emphasis on the growth objective and normally invests up to 75% of its
assets in equity securities selected primarily for their growth potential and at
least 25% of its assets in securities that the portfolio manager believes have
income potential. In unusual circumstances, the Fund may reduce the growth
component of its portfolio to 25% of its assets.
    
 
     JANUS FLEXIBLE INCOME FUND is a diversified fund that seeks to maximize
total return consistent with preservation of capital. Total return is expected
to result from a combination of current income and capital appreciation,
although income will normally be the dominant component of total return. Janus
Flexible Income Fund invests in all types of income-producing securities. This
Fund may have substantial holdings of debt securities rated below investment
grade.
 
   
     JANUS HIGH-YIELD FUND is a diversified fund that seeks high current income
as its primary objective and capital appreciation as its secondary objective
when consistent with the primary objective by investing in high-yield/high-risk
fixed-income securities. The Fund invests primarily in high-yield corporate debt
securities ("junk bonds") and may invest all of its assets in such securities.
    
 
     JANUS FEDERAL TAX-EXEMPT FUND is a diversified fund that seeks as high a
level of current income exempt from federal income tax as is consistent with
preservation of capital. It will normally invest at least 80% of its net assets
in securities whose income is not subject to federal income tax.
 
   
     JANUS SHORT-TERM BOND FUND is a diversified fund that seeks as high a level
of current income as is consistent with the preservation of capital by investing
primarily in short- and intermediate-term fixed-income securities. It will
normally maintain a dollar-weighted average portfolio effective maturity not to
exceed three years.
    
 
PORTFOLIO POLICIES
     The Funds' Prospectuses discuss the types of securities in which the Funds
will invest, portfolio policies of the Funds and the investment techniques of
the Funds. The Prospectuses include a discussion of portfolio turnover policies.
Portfolio turnover is calculated by dividing total purchases or sales, whichever
is less, by the average monthly value of a Fund's portfolio securities. The
following table summarizes the portfolio
 
                                        4
<PAGE>   
 
turnover rates for the fiscal periods indicated. The information below is for
fiscal years ended October 31.
 
   
<TABLE>
<CAPTION>
                      Fund Name                        1997+      1996
- ----------------------------------------------------------------------
<S>                                                    <C>        <C>
Janus Fund...........................................             104%
Janus Enterprise Fund................................              93%
Janus Mercury Fund...................................             177%
Janus Olympus Fund...................................             303%
Janus Overseas Fund..................................              71%
Janus Special Situations Fund........................              N/A
Janus Twenty Fund....................................             137%
Janus Worldwide Fund.................................              80%
Janus Balanced Fund..................................             151%
Janus Equity Income Fund.............................             325%(1)
Janus Growth and Income Fund.........................             153%
Janus Flexible Income Fund...........................             214%
Janus High-Yield Fund................................             324%
Janus Federal Tax-Exempt Fund........................             225%
Janus Short-Term Bond Fund...........................             486%
- ----------------------------------------------------------------------
</TABLE>
    
 
   
 + [To be filed by Amendment]
    
   
(1) Annualized rate based on the four month period ended October 31, 1996.
    
 
   
INVESTMENT RESTRICTIONS APPLICABLE TO ALL FUNDS
    
     As indicated in the Prospectus, the Funds are subject to certain
fundamental policies and restrictions that may not be changed without
shareholder approval. Shareholder approval means approval by the lesser of (i)
more than 50% of the outstanding voting securities of the Trust (or a particular
Fund if a matter affects just that Fund), or (ii) 67% or more of the voting
securities present at a meeting if the holders of more than 50% of the
outstanding voting securities of the Trust (or a particular Fund) are present or
represented by proxy. As fundamental policies, each of the Funds may not:
 
   
     (1) Own more than 10% of the outstanding voting securities of any one
issuer and, as to fifty percent (50%) of the value of the total assets for Janus
Enterprise Fund, Janus Olympus Fund, Janus Special Situations Fund, and Janus
Twenty Fund and as to seventy-five percent (75%) of the value of the total
assets of the other Funds, purchase the securities of any one issuer (except
cash items and "government securities" as defined under the Investment Company
Act of 1940, as amended (the "1940 Act")), if immediately after and as a result
of such purchase, the value of the holdings of a Fund in the securities of such
issuer exceeds 5% of the value of such Fund's total assets. With respect to the
other 50% of the value of their total assets, Janus Twenty Fund, Janus
Enterprise Fund, Janus Special Situations Fund and Janus Olympus Fund may invest
in the securities of as few as two issuers.
    
 
     (2) Invest 25% or more of the value of their respective total assets in any
particular industry (other than U.S. government securities); provided, however,
that for Janus Federal Tax-Exempt Fund this limitation does not apply to
municipal obligations. For the purposes of this limitation only, industrial
development bonds issued by
 
                                        5
<PAGE>   
 
nongovernmental users shall not be deemed to be municipal obligations.
Industrial development bonds shall be classified according to the industry of
the entity that has the ultimate responsibility for the payment of principal and
interest on the obligation.
 
     (3) Invest directly in real estate or interests in real estate; however,
the Funds may own debt or equity securities issued by companies engaged in those
businesses.
 
     (4) Purchase or sell physical commodities other than foreign currencies
unless acquired as a result of ownership of securities (but this limitation
shall not prevent the Funds from purchasing or selling options, futures, swaps
and forward contracts or from investing in securities or other instruments
backed by physical commodities).
 
     (5) Lend any security or make any other loan if, as a result, more than 25%
of a Fund's total assets would be lent to other parties (but this limitation
does not apply to purchases of commercial paper, debt securities or repurchase
agreements).
 
     (6) Act as an underwriter of securities issued by others, except to the
extent that a Fund may be deemed an underwriter in connection with the
disposition of portfolio securities of such Fund.
 
     As a fundamental policy, each Fund may, notwithstanding any other
investment policy or limitation (whether or not fundamental), invest all of its
assets in the securities of a single open-end management investment company with
substantially the same fundamental investment objectives, policies and
limitations as such Fund.
 
     The Trustees have adopted additional investment restrictions for the Funds.
These restrictions are operating policies of the Funds and may be changed by the
Trustees without shareholder approval. The additional investment restrictions
adopted by the Trustees to date include the following:
 
     (a) A Fund will not (i) enter into any futures contracts and related
options for purposes other than bona fide hedging transactions within the
meaning of Commodity Futures Trading Commission ("CFTC") regulations if the
aggregate initial margin and premiums required to establish positions in futures
contracts and related options that do not fall within the definition of bona
fide hedging transactions will exceed 5% of the fair market value of a Fund's
net assets, after taking into account unrealized profits and unrealized losses
on any such contracts it has entered into; and (ii) enter into any futures
contracts if the aggregate amount of such Fund's commitments under outstanding
futures contracts positions would exceed the market value of its total assets.
 
     (b) The Funds do not currently intend to sell securities short, unless they
own or have the right to obtain securities equivalent in kind and amount to the
securities sold short without the payment of any additional consideration
therefor, and provided that transactions in futures, options, swaps and forward
contracts are not deemed to constitute selling securities short.
 
     (c) The Funds do not currently intend to purchase securities on margin,
except that the Funds may obtain such short-term credits as are necessary for
the clearance of transactions, and provided that margin payments and other
deposits in connection with transactions in futures, options, swaps and forward
contracts shall not be deemed to constitute purchasing securities on margin.
 
                                        6
<PAGE>   
 
     (d) A Fund may not mortgage or pledge any securities owned or held by such
Fund in amounts that exceed, in the aggregate, 15% of that Fund's net asset
value, provided that this limitation does not apply to reverse repurchase
agreements, deposits of assets to margin, guarantee positions in futures,
options, swaps or forward contracts, or the segregation of assets in connection
with such contracts.
 
     (e) The Funds may borrow money for temporary or emergency purposes (not for
leveraging or investment) in an amount not exceeding 25% of the value of their
respective total assets (including the amount borrowed) less liabilities (other
than borrowings). If borrowings exceed 25% of the value of a Fund's total assets
by reason of a decline in net assets, the Fund will reduce its borrowings within
three business days to the extent necessary to comply with the 25% limitation.
This policy shall not prohibit reverse repurchase agreements, deposits of assets
to margin or guarantee positions in futures, options, swaps or forward
contracts, or the segregation of assets in connection with such contracts.
 
     (f) The Funds do not currently intend to purchase any security or enter
into a repurchase agreement if, as a result, more than 15% of their respective
net assets would be invested in repurchase agreements not entitling the holder
to payment of principal and interest within seven days and in securities that
are illiquid by virtue of legal or contractual restrictions on resale or the
absence of a readily available market. The Trustees, or the Funds' investment
adviser acting pursuant to authority delegated by the Trustees, may determine
that a readily available market exists for securities eligible for resale
pursuant to Rule 144A under the Securities Act of 1933 ("Rule 144A Securities"),
or any successor to such rule, Section 4(2) commercial paper and municipal lease
obligations. Accordingly, such securities may not be subject to the foregoing
limitation.
 
     (g) The Funds may not invest in companies for the purpose of exercising
control of management.
 
   
     Under the terms of an exemptive order received from the Securities and
Exchange Commission ("SEC"), each of the Funds may borrow money from or lend
money to other funds that permit such transactions and for which Janus Capital
serves as investment adviser. All such borrowing and lending will be subject to
the above limits.  A Fund will borrow money through the program only when the
costs are equal to or lower than the cost of bank loans.  Interfund loans and 
borrowings normally extend overnight, but can have a maximum duration of seven 
days.  A Fund will lend through the program only when the returns are higher 
than those available from other short-term instruments (such as repurchase 
agreements).  A Fund may have to borrow from a bank at a higher interest rate
if an interfund loan is called or not renewed.  Any delay in repayment to a 
lending Fund could result in a lost investment opportunity or additional 
borrowing costs.
      
    
 
     For the purposes of these investment restrictions, the identification of
the issuer of a municipal obligation depends on the terms and conditions of the
security. When assets and revenues of a political subdivision are separate from
those of the government that created the subdivision and the security is backed
only by the assets and revenues of the subdivision, the subdivision is deemed to
be the sole issuer. Similarly, in the case of an industrial development bond, if
the bond is backed only by assets and revenues of a nongovernmental user, then
the nongovernmental user would be deemed to be the sole issuer. If, however, in
either case, the creating government or some other entity guarantees the
security, the guarantee would be considered a separate security that would be
treated as an issue of the guaranteeing entity.
 
     For purposes of the Funds' restriction on investing in a particular
industry, the Funds will rely primarily on industry classifications as published
by Bloomberg L.P. To the extent that Bloomberg L.P. classifications are so broad
that the primary economic
 
                                        7
<PAGE>   
 
   
characteristics in a single class are materially different, the Funds may
further classify issuers in accordance with industry classifications as
published by the SEC.
    
 
INVESTMENT POLICIES APPLICABLE TO CERTAIN FUNDS
     JANUS BALANCED FUND. As an operational policy, at least 25% of the assets
of Janus Balanced Fund normally will be invested in fixed-income senior
securities, which include debt securities and preferred stock.
 
     JANUS FLEXIBLE INCOME FUND. As a fundamental policy, this Fund may not
purchase a non-income-producing security if, after such purchase, less than 80%
of the Fund's total assets would be invested in income-producing securities.
Income-producing securities include securities that make periodic interest
payments as well as those that make interest payments on a deferred basis or pay
interest only at maturity (e.g., Treasury bills or zero coupon bonds).
 
     JANUS FEDERAL TAX-EXEMPT FUND. As a fundamental policy, this Fund will
normally invest at least 80% of its net assets in securities whose income is not
subject to federal income taxes, including the alternative minimum tax.
 
     JANUS SHORT-TERM BOND FUND. As an operational policy, this Fund will not
invest in any debt security that, at the time of purchase, causes its portfolio
of debt securities to have a dollar-weighted average, then remaining effective
term to maturity of three years or more. The portfolio manager may consider
estimated prepayment dates or call dates of certain securities in computing the
portfolio's effective maturity.
 
                              TYPES OF SECURITIES
                           AND INVESTMENT TECHNIQUES
 
ILLIQUID INVESTMENTS
   
     Each Fund may invest up to 15% of its net assets in illiquid investments
(i.e., securities that are not readily marketable). The Trustees have authorized
Janus Capital to make liquidity determinations with respect to certain
securities, including Rule 144A Securities, commercial paper and municipal lease
obligations, purchased by the Funds. Under the guidelines established by the
Trustees, Janus Capital will consider the following factors: 1) the frequency of
trades and quoted prices for the obligation; 2) the number of dealers willing to
purchase or sell the security and the number of other potential purchasers; 3)
the willingness of dealers to undertake to make a market in the security; and 4)
the nature of the security and the nature of marketplace trades, including the
time needed to dispose of the security, the method of soliciting offers and the
mechanics of the transfer. In the case of commercial paper, Janus Capital will
also consider whether the paper is traded flat or in default as to principal and
interest and any ratings of the paper by a nationally recognized statistical
rating organization ("NRSRO"). With respect to municipal lease obligations,
Janus Capital will also consider factors unique to municipal lease obligations
including the general creditworthiness of the municipality, the importance of
the property covered by the lease obligation and the likelihood that the
marketability of the obligation will be maintained throughout the time the
obligation is held by a Fund. A foreign security that may be freely traded
    
 
                                        8
<PAGE>   
 
on or through the facilities of an offshore exchange or other established
offshore securities market is not deemed to be a restricted security subject to
these procedures.
 
ZERO COUPON, PAY-IN-KIND AND STEP COUPON SECURITIES
   
     Each Fund may invest up to 10% (without limit for Janus High-Yield Fund and
Janus Flexible Income Fund) of its assets in zero coupon, pay-in-kind and step
coupon securities. Zero coupon bonds are issued and traded at a discount from
their face value. They do not entitle the holder to any periodic payment of
interest prior to maturity. Step coupon bonds trade at a discount from their
face value and pay coupon interest. The coupon rate is low for an initial period
and then increases to a higher coupon rate thereafter. The discount from the
face amount or par value depends on the time remaining until cash payments
begin, prevailing interest rates, liquidity of the security and the perceived
credit quality of the issuer. Pay-in-kind bonds normally give the issuer an
option to pay cash at a coupon payment date or give the holder of the security a
similar bond with the same coupon rate and a face value equal to the amount of
the coupon payment that would have been made.
    
 
     Current federal income tax law requires holders of zero coupon securities
and step coupon securities to report the portion of the original issue discount
on such securities that accrues during a given year as interest income, even
though the holders receive no cash payments of interest during the year. In
order to qualify as a "regulated investment company" under the Internal Revenue
Code of 1986 and the regulations thereunder (the "Code"), a Fund must distribute
its investment company taxable income, including the original issue discount
accrued on zero coupon or step coupon bonds. Because a Fund will not receive
cash payments on a current basis in respect of accrued original-issue discount
on zero coupon bonds or step coupon bonds during the period before interest
payments begin, in some years that Fund may have to distribute cash obtained
from other sources in order to satisfy the distribution requirements under the
Code. A Fund might obtain such cash from selling other portfolio holdings which
might cause that Fund to incur capital gains or losses on the sale.
Additionally, these actions are likely to reduce the assets to which Fund
expenses could be allocated and to reduce the rate of return for that Fund. In
some circumstances, such sales might be necessary in order to satisfy cash
distribution requirements even though investment considerations might otherwise
make it undesirable for a Fund to sell the securities at the time.
 
     Generally, the market prices of zero coupon, step coupon and pay-in-kind
securities are more volatile than the prices of securities that pay interest
periodically and in cash and are likely to respond to changes in interest rates
to a greater degree than other types of debt securities having similar
maturities and credit quality.
 
PASS-THROUGH SECURITIES
     The Funds may invest in various types of pass-through securities, such as
mortgage-backed securities, asset-backed securities and participation interests.
A pass-through security is a share or certificate of interest in a pool of debt
obligations that have been repackaged by an intermediary, such as a bank or
broker-dealer. The purchaser of a pass-through security receives an undivided
interest in the underlying pool of securities. The issuers of the underlying
securities make interest and principal payments to the intermediary which are
passed through to purchasers, such as the
 
                                        9
<PAGE>   
 
Funds. The most common type of pass-through securities are mortgage-backed
securities. Government National Mortgage Association ("GNMA") Certificates are
mortgage-backed securities that evidence an undivided interest in a pool of
mortgage loans. GNMA Certificates differ from bonds in that principal is paid
back monthly by the borrowers over the term of the loan rather than returned in
a lump sum at maturity. A Fund will generally purchase "modified pass-through"
GNMA Certificates, which entitle the holder to receive a share of all interest
and principal payments paid and owned on the mortgage pool, net of fees paid to
the "issuer" and GNMA, regardless of whether or not the mortgagor actually makes
the payment. GNMA Certificates are backed as to the timely payment of principal
and interest by the full faith and credit of the U.S. government.
 
     The Federal Home Loan Mortgage Corporation ("FHLMC") issues two types of
mortgage pass-through securities: mortgage participation certificates ("PCs")
and guaranteed mortgage certificates ("GMCs"). PCs resemble GNMA Certificates in
that each PC represents a pro rata share of all interest and principal payments
made and owned on the underlying pool. FHLMC guarantees timely payments of
interest on PCs and the full return of principal. GMCs also represent a pro rata
interest in a pool of mortgages. However, these instruments pay interest
semiannually and return principal once a year in guaranteed minimum payments.
This type of security is guaranteed by FHLMC as to timely payment of principal
and interest but it is not guaranteed by the full faith and credit of the U.S.
government.
 
     The Federal National Mortgage Association ("FNMA") issues guaranteed
mortgage pass-through certificates ("FNMA Certificates"). FNMA Certificates
resemble GNMA Certificates in that each FNMA Certificate represents a pro rata
share of all interest and principal payments made and owned on the underlying
pool. This type of security is guaranteed by FNMA as to timely payment of
principal and interest but it is not guaranteed by the full faith and credit of
the U.S. government.
 
     Except for GMCs, each of the mortgage-backed securities described above is
characterized by monthly payments to the holder, reflecting the monthly payments
made by the borrowers who received the underlying mortgage loans. The payments
to the security holders (such as the Funds), like the payments on the underlying
loans, represent both principal and interest. Although the underlying mortgage
loans are for specified periods of time, such as 20 or 30 years, the borrowers
can, and typically do, pay them off sooner. Thus, the security holders
frequently receive prepayments of principal in addition to the principal that is
part of the regular monthly payments. A portfolio manager will consider
estimated prepayment rates in calculating the average weighted maturity of a
Fund. A borrower is more likely to prepay a mortgage that bears a relatively
high rate of interest. This means that in times of declining interest rates,
higher yielding mortgage-backed securities held by a Fund might be converted to
cash and that Fund will be forced to accept lower interest rates when that cash
is used to purchase additional securities in the mortgage-backed securities
sector or in other investment sectors. Additionally, prepayments during such
periods will limit a Fund's ability to participate in as large a market gain as
may be experienced with a comparable security not subject to prepayment.
 
     Asset-backed securities represent interests in pools of consumer loans and
are backed by paper or accounts receivables originated by banks, credit card
companies or
 
                                       10
<PAGE>   
 
other providers of credit. Generally, the originating bank or credit provider is
neither the obligor or guarantor of the security and interest and principal
payments ultimately depend upon payment of the underlying loans by individuals.
Tax-exempt asset-backed securities include units of beneficial interests in
pools of purchase contracts, financing leases, and sales agreements that may be
created when a municipality enters into an installment purchase contract or
lease with a vendor. Such securities may be secured by the assets purchased or
leased by the municipality; however, if the municipality stops making payments,
there generally will be no recourse against the vendor. The market for
tax-exempt asset-backed securities is still relatively new. These obligations
are likely to involve unscheduled prepayments of principal.
 
INVESTMENT COMPANY SECURITIES
   
     From time to time, the Funds may invest in securities of other investment
companies, subject to the provisions of Section 12(d)(1) of the 1940 Act. The
Funds may invest in securities of money market funds managed by Janus Capital
subject to the terms of an exemptive order obtained by Janus Capital and the
Janus funds which currently provides that each Fund will limit its aggregate
investment in a Janus money market fund to the greater of (i) 5% of its total
assets or (ii) $2.5 million. The Janus funds are seeking an amended and restated
exemptive order that would permit each Fund to invest in Janus money market
funds in excess of the limitations of Section 12(d)(1) of the 1940 Act. There is
no assurance that such amendment will be granted.
    
 
DEPOSITARY RECEIPTS
     The Funds may invest in sponsored and unsponsored American Depositary
Receipts ("ADRs"), which are receipts issued by an American bank or trust
company evidencing ownership of underlying securities issued by a foreign
issuer. ADRs, in registered form, are designed for use in U.S. securities
markets. Unsponsored ADRs may be created without the participation of the
foreign issuer. Holders of these ADRs generally bear all the costs of the ADR
facility, whereas foreign issuers typically bear certain costs in a sponsored
ADR. The bank or trust company depositary of an unsponsored ADR may be under no
obligation to distribute shareholder communications received from the foreign
issuer or to pass through voting rights. The Funds may also invest in European
Depositary Receipts ("EDRs"), Global Depositary Receipts ("GDRs") and in other
similar instruments representing securities of foreign companies. EDRs are
receipts issued by a European financial institution evidencing an arrangement
similar to that of ADRs. EDRs, in bearer form, are designed for use in European
securities markets.
 
MUNICIPAL OBLIGATIONS
     The Funds may invest in municipal obligations issued by states, territories
and possessions of the United States and the District of Columbia. Janus Federal
Tax-Exempt Fund may, at times, invest more than 25% of the value of its assets
in industrial development bonds, a type of revenue bond which, although issued
by a public authority, may be backed only by the credit and security of a
private issuer, thus presenting a greater credit risk.
 
                                       11
<PAGE>   
 
     The value of municipal obligations can be affected by changes in their
actual or perceived credit quality. The credit quality of municipal obligations
can be affected by among other things, the financial condition of the issuer or
guarantor, the issuer's future borrowing plans and sources of revenue, the
economic feasibility of the revenue bond project or general borrowing purpose,
political or economic developments in the region where the security is issued,
and the liquidity of the security. Because municipal securities are generally
traded over-the-counter, the liquidity of a particular issue often depends on
the willingness of dealers to make a market in the security. The liquidity of
some municipal obligations may be enhanced by demand features, which would
enable a Fund to demand payment on short notice from the issuer or a financial
intermediary.
 
OTHER INCOME-PRODUCING SECURITIES
     Other types of income producing securities that the Funds may purchase
include, but are not limited to, the following types of securities:
 
     VARIABLE AND FLOATING RATE OBLIGATIONS. These types of securities are
relatively long-term instruments that often carry demand features permitting the
holder to demand payment of principal at any time or at specified intervals
prior to maturity.
 
     STANDBY COMMITMENTS. These instruments, which are similar to a put, give a
Fund the option to obligate a broker, dealer or bank to repurchase a security
held by that Fund at a specified price.
 
     TENDER OPTION BONDS. Tender option bonds are relatively long-term bonds
that are coupled with the agreement of a third party (such as a broker, dealer
or bank) to grant the holders of such securities the option to tender the
securities to the institution at periodic intervals.
 
     INVERSE FLOATERS. Inverse floaters are debt instruments whose interest
bears an inverse relationship to the interest rate on another security. The
Funds will not invest more than 5% of their respective assets in inverse
floaters.
 
     The Funds will purchase standby commitments, tender option bonds and
instruments with demand features primarily for the purpose of increasing the
liquidity of their portfolios.
 
REPURCHASE AND REVERSE REPURCHASE AGREEMENTS
     In a repurchase agreement, a Fund purchases a security and simultaneously
commits to resell that security to the seller at an agreed upon price on an
agreed upon date within a number of days (usually not more than seven) from the
date of purchase. The resale price reflects the purchase price plus an agreed
upon incremental amount that is unrelated to the coupon rate or maturity of the
purchased security. A repurchase agreement involves the obligation of the seller
to pay the agreed upon price, which obligation is in effect secured by the value
(at least equal to the amount of the agreed upon resale price and
marked-to-market daily) of the underlying security or "collateral." A Fund may
engage in a repurchase agreement with respect to any security in which it is
authorized to invest. A risk associated with repurchase agreements is the
failure of the seller to repurchase the securities as agreed, which may cause a
Fund to suffer a loss if the market value of such securities declines before
they can be liquidated on the open market. In the event of bankruptcy or
insolvency of the seller, a Fund may
 
                                       12
<PAGE>   
 
encounter delays and incur costs in liquidating the underlying security.
Repurchase agreements that mature in more than seven days will be subject to the
15% limit on illiquid investments. While it is not possible to eliminate all
risks from these transactions, it is the policy of the Funds to limit repurchase
agreements to those parties whose creditworthiness has been reviewed and found
satisfactory by Janus Capital.
 
     A Fund may use reverse repurchase agreements to provide cash to satisfy
unusually heavy redemption requests or for other temporary or emergency purposes
without the necessity of selling portfolio securities, or to earn additional
income on portfolio securities, such as Treasury bills or notes. In a reverse
repurchase agreement, a Fund sells a portfolio security to another party, such
as a bank or broker-dealer, in return for cash and agrees to repurchase the
instrument at a particular price and time. While a reverse repurchase agreement
is outstanding, a Fund will maintain cash and appropriate liquid assets in a
segregated custodial account to cover its obligation under the agreement. The
Funds will enter into reverse repurchase agreements only with parties that Janus
Capital deems creditworthy. Using reverse repurchase agreements to earn
additional income involves the risk that the interest earned on the invested
proceeds is less than the expense of the reverse repurchase agreement
transaction. This technique may also have a leveraging effect on the Fund's
portfolio, although the Fund's intent to segregate assets in the amount of the
reverse repurchase agreement minimizes this effect.
 
HIGH-YIELD/HIGH-RISK SECURITIES
     Janus Flexible Income Fund and Janus High-Yield Fund may invest without
limit in debt securities that are rated below investment grade (e.g., securities
rated BB or lower by Standard & Poor's Ratings Services ("Standard & Poor's") or
Ba or lower by Moody's Investors Service, Inc. ("Moody's")). No other Fund
intends to invest 35% or more of its net assets in such securities. Lower rated
securities involve a higher degree of credit risk, which is the risk that the
issuer will not make interest or principal payments when due. In the event of an
unanticipated default, a Fund would experience a reduction in its income, and
could expect a decline in the market value of the securities so affected.
 
     Each Fund may also invest in unrated debt securities of foreign and
domestic issuers. Unrated debt, while not necessarily of lower quality than
rated securities, may not have as broad a market. Because of the size and
perceived demand of the issue, among other factors, certain municipalities may
not incur the costs of obtaining a rating. A Fund's portfolio manager will
analyze the creditworthiness of the issuer, as well as any financial institution
or other party responsible for payments on the security, in determining whether
to purchase unrated municipal bonds. Unrated debt securities will be included in
the 35% limit of each Fund unless its portfolio manager deems such securities to
be the equivalent of investment grade securities.
 
     Subject to the above limits, each Fund may purchase defaulted securities
only when their portfolio managers believe, based upon their analysis of the
financial condition, results of operations and economic outlook of an issuer,
that there is potential for resumption of income payments and that the
securities offer an unusual opportunity for capital appreciation.
Notwithstanding the respective portfolio manager's belief as to the resumption
of income, however, the purchase of any security on which payment of
 
                                       13
<PAGE>   
 
interest or dividends is suspended involves a high degree of risk. Such risk
includes, among other things, the following:
 
     Financial and Market Risks. Investments in securities that are in default
involve a high degree of financial and market risks that can result in
substantial or, at times, even total losses. Issuers of defaulted securities may
have substantial capital needs and may become involved in bankruptcy or
reorganization proceedings. Among the problems involved in investments in such
issuers is the fact that it may be difficult to obtain information about the
condition of such issuers. The market prices of such securities also are subject
to abrupt and erratic movements and above average price volatility, and the
spread between the bid and asked prices of such securities may be greater than
normally expected.
 
     Disposition of Portfolio Securities. Although these Funds generally will
purchase securities for which their portfolio managers expect an active market
to be maintained, defaulted securities may be less actively traded than other
securities and it may be difficult to dispose of substantial holdings of such
securities at prevailing market prices. The Funds will limit holdings of any
such securities to amounts that the portfolio managers believe could be readily
sold, and holdings of such securities would, in any event, be limited so as not
to limit the Funds' ability to readily dispose of securities to meet
redemptions.
 
     Other. Defaulted securities require active monitoring and may, at times,
require participation in bankruptcy or receivership proceedings on behalf of the
Funds.
 
FUTURES, OPTIONS AND OTHER DERIVATIVE INSTRUMENTS
     FUTURES CONTRACTS. The Funds may enter into contracts for the purchase or
sale for future delivery of fixed-income securities, foreign currencies or
contracts based on financial indices, including indices of U.S. government
securities, foreign government securities, equity or fixed-income securities.
U.S. futures contracts are traded on exchanges which have been designated
"contract markets" by the CFTC and must be executed through a futures commission
merchant ("FCM"), or brokerage firm, which is a member of the relevant contract
market. Through their clearing corporations, the exchanges guarantee performance
of the contracts as between the clearing members of the exchange.
 
     The buyer or seller of a futures contract is not required to deliver or pay
for the underlying instrument unless the contract is held until the delivery
date. However, both the buyer and seller are required to deposit "initial
margin" for the benefit of the FCM when the contract is entered into. Initial
margin deposits are equal to a percentage of the contract's value, as set by the
exchange on which the contract is traded, and may be maintained in cash or
certain other liquid assets by the Funds' custodian for the benefit of the FCM.
Initial margin payments are similar to good faith deposits or performance bonds.
Unlike margin extended by a securities broker, initial margin payments do not
constitute purchasing securities on margin for purposes of the Fund's investment
limitations. If the value of either party's position declines, that party will
be required to make additional "variation margin" payments for the benefit of
the FCM to settle the change in value on a daily basis. The party that has a
gain may be entitled to receive all or a portion of this amount. In the event of
the bankruptcy of the FCM that holds
 
                                       14
<PAGE>   
 
margin on behalf of a Fund, that Fund may be entitled to return of margin owed
to such Fund only in proportion to the amount received by the FCM's other
customers. Janus Capital will attempt to minimize the risk by careful monitoring
of the creditworthiness of the FCMs with which the Funds do business and by
depositing margin payments in a segregated account with the Funds' custodian.
 
     The Funds intend to comply with guidelines of eligibility for exclusion
from the definition of the term "commodity pool operator" adopted by the CFTC
and the National Futures Association, which regulate trading in the futures
markets. The Funds will use futures contracts and related options primarily for
bona fide hedging purposes within the meaning of CFTC regulations. To the extent
that the Funds hold positions in futures contracts and related options that do
not fall within the definition of bona fide hedging transactions, the aggregate
initial margin and premiums required to establish such positions will not exceed
5% of the fair market value of a Fund's net assets, after taking into account
unrealized profits and unrealized losses on any such contracts it has entered
into.
 
     Although a Fund will segregate cash and liquid assets in an amount
sufficient to cover its open futures obligations, the segregated assets would be
available to that Fund immediately upon closing out the futures position, while
settlement of securities transactions could take several days. However, because
a Fund's cash that may otherwise be invested would be held uninvested or
invested in other liquid assets so long as the futures position remains open,
such Fund's return could be diminished due to the opportunity losses of
foregoing other potential investments.
 
     A Fund's primary purpose in entering into futures contracts is to protect
that Fund from fluctuations in the value of securities or interest rates without
actually buying or selling the underlying debt or equity security. For example,
if the Fund anticipates an increase in the price of stocks, and it intends to
purchase stocks at a later time, that Fund could enter into a futures contract
to purchase a stock index as a temporary substitute for stock purchases. If an
increase in the market occurs that influences the stock index as anticipated,
the value of the futures contracts will increase, thereby serving as a hedge
against that Fund not participating in a market advance. This technique is
sometimes known as an anticipatory hedge. To the extent a Fund enters into
futures contracts for this purpose, the segregated assets maintained to cover
such Fund's obligations with respect to the futures contracts will consist of
other liquid assets from its portfolio in an amount equal to the difference
between the contract price and the aggregate value of the initial and variation
margin payments made by that Fund with respect to the futures contracts.
Conversely, if a Fund holds stocks and seeks to protect itself from a decrease
in stock prices, the Fund might sell stock index futures contracts, thereby
hoping to offset the potential decline in the value of its portfolio securities
by a corresponding increase in the value of the futures contract position. A
Fund could protect against a decline in stock prices by selling portfolio
securities and investing in money market instruments, but the use of futures
contracts enables it to maintain a defensive position without having to sell
portfolio securities.
 
     If a Fund owns Treasury bonds and the portfolio manager expects interest
rates to increase, that Fund may take a short position in interest rate futures
contracts. Taking such a position would have much the same effect as that Fund
selling Treasury bonds in its portfolio. If interest rates increase as
anticipated, the value of the Treasury bonds
 
                                       15
<PAGE>   
 
would decline, but the value of that Fund's interest rate futures contract will
increase, thereby keeping the net asset value of that Fund from declining as
much as it may have otherwise. If, on the other hand, a portfolio manager
expects interest rates to decline, that Fund may take a long position in
interest rate futures contracts in anticipation of later closing out the futures
position and purchasing the bonds. Although a Fund can accomplish similar
results by buying securities with long maturities and selling securities with
short maturities, given the greater liquidity of the futures market than the
cash market, it may be possible to accomplish the same result more easily and
more quickly by using futures contracts as an investment tool to reduce risk.
 
     The ordinary spreads between prices in the cash and futures markets, due to
differences in the nature of those markets, are subject to distortions. First,
all participants in the futures market are subject to initial margin and
variation margin requirements. Rather than meeting additional variation margin
requirements, investors may close out futures contracts through offsetting
transactions which could distort the normal price relationship between the cash
and futures markets. Second, the liquidity of the futures market depends on
participants entering into offsetting transactions rather than making or taking
delivery of the instrument underlying a futures contract. To the extent
participants decide to make or take delivery, liquidity in the futures market
could be reduced and prices in the futures market distorted. Third, from the
point of view of speculators, the margin deposit requirements in the futures
market are less onerous than margin requirements in the securities market.
Therefore, increased participation by speculators in the futures market may
cause temporary price distortions. Due to the possibility of the foregoing
distortions, a correct forecast of general price trends by a portfolio manager
still may not result in a successful use of futures.
 
     Futures contracts entail risks. Although the Funds believe that use of such
contracts will benefit the Funds, a Fund's overall performance could be worse
than if such Fund had not entered into futures contracts if the portfolio
manager's investment judgement proves incorrect. For example, if a Fund has
hedged against the effects of a possible decrease in prices of securities held
in its portfolio and prices increase instead, that Fund will lose part or all of
the benefit of the increased value of these securities because of offsetting
losses in its futures positions. In addition, if a Fund has insufficient cash,
it may have to sell securities from its portfolio to meet daily variation margin
requirements. Those sales may be, but will not necessarily be, at increased
prices which reflect the rising market and may occur at a time when the sales
are disadvantageous to such Fund.
 
     The prices of futures contracts depend primarily on the value of their
underlying instruments. Because there are a limited number of types of futures
contracts, it is possible that the standardized futures contracts available to a
Fund will not match exactly such Fund's current or potential investments. A Fund
may buy and sell futures contracts based on underlying instruments with
different characteristics from the securities in which it typically
invests -- for example, by hedging investments in portfolio securities with a
futures contract based on a broad index of securities -- which involves a risk
that the futures position will not correlate precisely with the performance of
such Fund's investments.
 
     Futures prices can also diverge from the prices of their underlying
instruments, even if the underlying instruments closely correlate with a Fund's
investments. Futures
 
                                       16
<PAGE>   
 
prices are affected by factors such as current and anticipated short-term
interest rates, changes in volatility of the underlying instruments and the time
remaining until expiration of the contract. Those factors may affect securities
prices differently from futures prices. Imperfect correlations between a Fund's
investments and its futures positions also may result from differing levels of
demand in the futures markets and the securities markets, from structural
differences in how futures and securities are traded, and from imposition of
daily price fluctuation limits for futures contracts. A Fund may buy or sell
futures contracts with a greater or lesser value than the securities it wishes
to hedge or is considering purchasing in order to attempt to compensate for
differences in historical volatility between the futures contract and the
securities, although this may not be successful in all cases. If price changes
in a Fund's futures positions are poorly correlated with its other investments,
its futures positions may fail to produce desired gains or result in losses that
are not offset by the gains in that Fund's other investments.
 
     Because futures contracts are generally settled within a day from the date
they are closed out, compared with a settlement period of three days for some
types of securities, the futures markets can provide superior liquidity to the
securities markets. Nevertheless, there is no assurance that a liquid secondary
market will exist for any particular futures contract at any particular time. In
addition, futures exchanges may establish daily price fluctuation limits for
futures contracts and may halt trading if a contract's price moves upward or
downward more than the limit in a given day. On volatile trading days when the
price fluctuation limit is reached, it may be impossible for a Fund to enter
into new positions or close out existing positions. If the secondary market for
a futures contract is not liquid because of price fluctuation limits or
otherwise, a Fund may not be able to promptly liquidate unfavorable futures
positions and potentially could be required to continue to hold a futures
position until the delivery date, regardless of changes in its value. As a
result, such Fund's access to other assets held to cover its futures positions
also could be impaired.
 
     OPTIONS ON FUTURES CONTRACTS. The Funds may buy and write put and call
options on futures contracts. An option on a future gives a Fund the right (but
not the obligation) to buy or sell a futures contract at a specified price on or
before a specified date. The purchase of a call option on a futures contract is
similar in some respects to the purchase of a call option on an individual
security. Depending on the pricing of the option compared to either the price of
the futures contract upon which it is based or the price of the underlying
instrument, ownership of the option may or may not be less risky than ownership
of the futures contract or the underlying instrument. As with the purchase of
futures contracts, when a Fund is not fully invested it may buy a call option on
a futures contract to hedge against a market advance.
 
     The writing of a call option on a futures contract constitutes a partial
hedge against declining prices of the security or foreign currency which is
deliverable under, or of the index comprising, the futures contract. If the
futures' price at the expiration of the option is below the exercise price, a
Fund will retain the full amount of the option premium which provides a partial
hedge against any decline that may have occurred in that Fund's portfolio
holdings. The writing of a put option on a futures contract constitutes a
partial hedge against increasing prices of the security or foreign currency
which is deliverable under, or of the index comprising, the futures contract. If
the futures' price at expiration of the option is higher than the exercise
price, a Fund will
 
                                       17
<PAGE>   
 
retain the full amount of the option premium which provides a partial hedge
against any increase in the price of securities which that Fund is considering
buying. If a call or put option a Fund has written is exercised, such Fund will
incur a loss which will be reduced by the amount of the premium it received.
Depending on the degree of correlation between the change in the value of its
portfolio securities and changes in the value of the futures positions, a Fund's
losses from existing options on futures may to some extent be reduced or
increased by changes in the value of portfolio securities.
 
     The purchase of a put option on a futures contract is similar in some
respects to the purchase of protective put options on portfolio securities. For
example, a Fund may buy a put option on a futures contract to hedge its
portfolio against the risk of falling prices or rising interest rates.
 
     The amount of risk a Fund assumes when it buys an option on a futures
contract is the premium paid for the option plus related transaction costs. In
addition to the correlation risks discussed above, the purchase of an option
also entails the risk that changes in the value of the underlying futures
contract will not be fully reflected in the value of the options bought.
 
     FORWARD CONTRACTS. A forward contract is an agreement between two parties
in which one party is obligated to deliver a stated amount of a stated asset at
a specified time in the future and the other party is obligated to pay a
specified amount for the assets at the time of delivery. The Funds may enter
into forward contracts to purchase and sell government securities, equity or
income securities, foreign currencies or other financial instruments. Forward
contracts generally are traded in an interbank market conducted directly between
traders (usually large commercial banks) and their customers. Unlike futures
contracts, which are standardized contracts, forward contracts can be
specifically drawn to meet the needs of the parties that enter into them. The
parties to a forward contract may agree to offset or terminate the contract
before its maturity, or may hold the contract to maturity and complete the
contemplated exchange.
 
     The following discussion summarizes the Funds' principal uses of forward
foreign currency exchange contracts ("forward currency contracts"). A Fund may
enter into forward currency contracts with stated contract values of up to the
value of that Fund's assets. A forward currency contract is an obligation to buy
or sell an amount of a specified currency for an agreed price (which may be in
U.S. dollars or a foreign currency). A Fund will exchange foreign currencies for
U.S. dollars and for other foreign currencies in the normal course of business
and may buy and sell currencies through forward currency contracts in order to
fix a price for securities it has agreed to buy or sell ("transaction hedge"). A
Fund also may hedge some or all of its investments denominated in a foreign
currency or exposed to foreign currency fluctuations against a decline in the
value of that currency relative to the U.S. dollar by entering into forward
currency contracts to sell an amount of that currency (or a proxy currency whose
performance is expected to replicate or exceed the performance of that currency
relative to the U.S. dollar) approximating the value of some or all of its
portfolio securities denominated in that currency ("position hedge") or by
participating in options or futures contracts with respect to the currency. A
Fund also may enter into a forward currency contract with respect to a currency
where the Fund is considering the purchase or sale of investments denominated in
that currency but has not yet selected the specific
 
                                       18
<PAGE>   
 
investments ("anticipatory hedge"). In any of these circumstances a Fund may,
alternatively, enter into a forward currency contract to purchase or sell one
foreign currency for a second currency that is expected to perform more
favorably relative to the U.S. dollar if the portfolio manager believes there is
a reasonable degree of correlation between movements in the two currencies
("cross-hedge").
 
     These types of hedging minimize the effect of currency appreciation as well
as depreciation, but do not eliminate fluctuations in the underlying U.S. dollar
equivalent value of the proceeds of or rates of return on a Fund's foreign
currency denominated portfolio securities. The matching of the increase in value
of a forward contract and the decline in the U.S. dollar equivalent value of the
foreign currency denominated asset that is the subject of the hedge generally
will not be precise. Shifting a Fund's currency exposure from one foreign
currency to another removes that Fund's opportunity to profit from increases in
the value of the original currency and involves a risk of increased losses to
such Fund if its portfolio manager's projection of future exchange rates is
inaccurate. Proxy hedges and cross-hedges may result in losses if the currency
used to hedge does not perform similarly to the currency in which hedged
securities are denominated. Unforeseen changes in currency prices may result in
poorer overall performance for a Fund than if it had not entered into such
contracts.
 
     The Funds will cover outstanding forward currency contracts by maintaining
liquid portfolio securities denominated in or whose value is tied to, the
currency underlying the forward contract or the currency being hedged. To the
extent that a Fund is not able to cover its forward currency positions with
underlying portfolio securities, the Funds' custodian will segregate cash or
other liquid assets having a value equal to the aggregate amount of such Fund's
commitments under forward contracts entered into with respect to position
hedges, cross-hedges and anticipatory hedges. If the value of the securities
used to cover a position or the value of segregated assets declines, a Fund will
find alternative cover or segregate additional cash or liquid assets on a daily
basis so that the value of the covered and segregated assets will be equal to
the amount of such Fund's commitments with respect to such contracts. As an
alternative to segregating assets, a Fund may buy call options permitting such
Fund to buy the amount of foreign currency being hedged by a forward sale
contract or a Fund may buy put options permitting it to sell the amount of
foreign currency subject to a forward buy contract.
 
     While forward contracts are not currently regulated by the CFTC, the CFTC
may in the future assert authority to regulate forward contacts. In such event,
the Funds' ability to utilize forward contracts may be restricted. In addition,
a Fund may not always be able to enter into forward contracts at attractive
prices and may be limited in its ability to use these contracts to hedge Fund
assets.
 
     OPTIONS ON FOREIGN CURRENCIES. The Funds may buy and write options on
foreign currencies in a manner similar to that in which futures or forward
contracts on foreign currencies will be utilized. For example, a decline in the
U.S. dollar value of a foreign currency in which portfolio securities are
denominated will reduce the U.S. dollar value of such securities, even if their
value in the foreign currency remains constant. In order to protect against such
diminutions in the value of portfolio securities, a Fund may buy put options on
the foreign currency. If the value of the currency declines, such Fund will have
the right to sell such currency for a fixed
 
                                       19
<PAGE>   
 
amount in U.S. dollars, thereby offsetting, in whole or in part, the adverse
effect on its portfolio.
 
   
     Conversely, when a rise in the U.S. dollar value of a currency in which
securities to be acquired are denominated is projected, thereby increasing the
cost of such securities, a Fund may buy call options on the foreign currency.
The purchase of such options could offset, at least partially, the effects of
the adverse movements in exchange rates. As in the case of other types of
options, however, the benefit to a Fund from purchases of foreign currency
options will be reduced by the amount of the premium and related transaction
costs. In addition, if currency exchange rates do not move in the direction or
to the extent projected, a Fund could sustain losses on transactions in foreign
currency options that would require such Fund to forego a portion or all of the
benefits of advantageous changes in those rates.
    
 
     The Funds may also write options on foreign currencies. For example, to
hedge against a potential decline in the U.S. dollar value of foreign currency
denominated securities due to adverse fluctuations in exchange rates, a Fund
could, instead of purchasing a put option, write a call option on the relevant
currency. If the expected decline occurs, the option will most likely not be
exercised and the decline in value of portfolio securities will be offset by the
amount of the premium received.
 
   
     Similarly, instead of purchasing a call option to hedge against a potential
increase in the U.S. dollar cost of securities to be acquired, a Fund could
write a put option on the relevant currency which, if rates move in the manner
projected, should expire unexercised and allow that Fund to hedge the increased
cost up to the amount of the premium. As in the case of other types of options,
however, the writing of a foreign currency option will constitute only a partial
hedge up to the amount of the premium. If exchange rates do not move in the
expected direction, the option may be exercised and a Fund would be required to
buy or sell the underlying currency at a loss which may not be offset by the
amount of the premium. Through the writing of options on foreign currencies, a
Fund also may lose all or a portion of the benefits which might otherwise have
been obtained from favorable movements in exchange rates.
    
 
     The Funds may write covered call options on foreign currencies. A call
option written on a foreign currency by a Fund is "covered" if that Fund owns
the foreign currency underlying the call or has an absolute and immediate right
to acquire that foreign currency without additional cash consideration (or for
additional cash consideration held in a segregated account by its custodian)
upon conversion or exchange of other foreign currencies held in its portfolio. A
call option is also covered if a Fund has a call on the same foreign currency in
the same principal amount as the call written if the exercise price of the call
held (i) is equal to or less than the exercise price of the call written or (ii)
is greater than the exercise price of the call written, if the difference is
maintained by such Fund in cash or other liquid assets in a segregated account
with the Funds' custodian.
 
     The Funds also may write call options on foreign currencies for
cross-hedging purposes. A call option on a foreign currency is for cross-hedging
purposes if it is designed to provide a hedge against a decline due to an
adverse change in the exchange rate in the U.S. dollar value of a security which
a Fund owns or has the right to acquire and which is denominated in the currency
underlying the option. Call options on foreign
 
                                       20
<PAGE>   
 
currencies which are entered into for cross-hedging purposes are not covered.
However, in such circumstances, a Fund will collateralize the option by
segregating cash or other liquid assets in an amount not less than the value of
the underlying foreign currency in U.S. dollars marked-to-market daily.
 
     OPTIONS ON SECURITIES. In an effort to increase current income and to
reduce fluctuations in net asset value, the Funds may write covered put and call
options and buy put and call options on securities that are traded on United
States and foreign securities exchanges and over-the-counter. The Funds may
write and buy options on the same types of securities that the Funds may
purchase directly.
 
     A put option written by a Fund is "covered" if that Fund (i) segregates
cash not available for investment or other liquid assets with a value equal to
the exercise price of the put with the Funds' custodian or (ii) holds a put on
the same security and in the same principal amount as the put written and the
exercise price of the put held is equal to or greater than the exercise price of
the put written. The premium paid by the buyer of an option will reflect, among
other things, the relationship of the exercise price to the market price and the
volatility of the underlying security, the remaining term of the option, supply
and demand and interest rates.
 
     A call option written by a Fund is "covered" if that Fund owns the
underlying security covered by the call or has an absolute and immediate right
to acquire that security without additional cash consideration (or for
additional cash consideration held in a segregated account by the Funds'
custodian) upon conversion or exchange of other securities held in its
portfolio. A call option is also deemed to be covered if a Fund holds a call on
the same security and in the same principal amount as the call written and the
exercise price of the call held (i) is equal to or less than the exercise price
of the call written or (ii) is greater than the exercise price of the call
written if the difference is maintained by that Fund in cash and other liquid
assets in a segregated account with its custodian.
 
     The Funds also may write call options that are not covered for
cross-hedging purposes. A Fund collateralizes its obligation under a written
call option for cross-hedging purposes by segregating cash or other liquid
assets in an amount not less than the market value of the underlying security,
marked-to-market daily. A Fund would write a call option for cross-hedging
purposes, instead of writing a covered call option, when the premium to be
received from the cross-hedge transaction would exceed that which would be
received from writing a covered call option and its portfolio manager believes
that writing the option would achieve the desired hedge.
 
     The writer of an option may have no control over when the underlying
securities must be sold, in the case of a call option, or bought, in the case of
a put option, since with regard to certain options, the writer may be assigned
an exercise notice at any time prior to the termination of the obligation.
Whether or not an option expires unexercised, the writer retains the amount of
the premium. This amount, of course, may, in the case of a covered call option,
be offset by a decline in the market value of the underlying security during the
option period. If a call option is exercised, the writer experiences a profit or
loss from the sale of the underlying security. If a put option is exercised, the
writer must fulfill the obligation to buy the underlying security at the
 
                                       21
<PAGE>   
 
exercise price, which will usually exceed the then market value of the
underlying security.
 
     The writer of an option that wishes to terminate its obligation may effect
a "closing purchase transaction." This is accomplished by buying an option of
the same series as the option previously written. The effect of the purchase is
that the writer's position will be canceled by the clearing corporation.
However, a writer may not effect a closing purchase transaction after being
notified of the exercise of an option. Likewise, an investor who is the holder
of an option may liquidate its position by effecting a "closing sale
transaction." This is accomplished by selling an option of the same series as
the option previously bought. There is no guarantee that either a closing
purchase or a closing sale transaction can be effected.
 
     In the case of a written call option, effecting a closing transaction will
permit a Fund to write another call option on the underlying security with
either a different exercise price or expiration date or both. In the case of a
written put option, such transaction will permit a Fund to write another put
option to the extent that the exercise price is secured by other liquid assets.
Effecting a closing transaction also will permit a Fund to use the cash or
proceeds from the concurrent sale of any securities subject to the option for
other investments. If a Fund desires to sell a particular security from its
portfolio on which it has written a call option, such Fund will effect a closing
transaction prior to or concurrent with the sale of the security.
 
     A Fund will realize a profit from a closing transaction if the price of the
purchase transaction is less than the premium received from writing the option
or the price received from a sale transaction is more than the premium paid to
buy the option. A Fund will realize a loss from a closing transaction if the
price of the purchase transaction is more than the premium received from writing
the option or the price received from a sale transaction is less than the
premium paid to buy the option. Because increases in the market of a call option
generally will reflect increases in the market price of the underlying security,
any loss resulting from the repurchase of a call option is likely to be offset
in whole or in part by appreciation of the underlying security owned by a Fund.
 
     An option position may be closed out only where a secondary market for an
option of the same series exists. If a secondary market does not exist, the Fund
may not be able to effect closing transactions in particular options and the
Fund would have to exercise the options in order to realize any profit. If a
Fund is unable to effect a closing purchase transaction in a secondary market,
it will not be able to sell the underlying security until the option expires or
it delivers the underlying security upon exercise. The absence of a liquid
secondary market may be due to the following: (i) insufficient trading interest
in certain options, (ii) restrictions imposed by a national securities exchange
("Exchange") on which the option is traded on opening or closing transactions or
both, (iii) trading halts, suspensions or other restrictions imposed with
respect to particular classes or series of options or underlying securities,
(iv) unusual or unforeseen circumstances that interrupt normal operations on an
Exchange, (v) the facilities of an Exchange or of the Options Clearing
Corporation ("OCC") may not at all times be adequate to handle current trading
volume, or (vi) one or more Exchanges could, for economic or other reasons,
decide or be compelled at some future date to discontinue the trading of options
(or a particular class or series of options), in which event the secondary
market on that Exchange (or in that class or series of options)
 
                                       22
<PAGE>   
 
would cease to exist, although outstanding options on that Exchange that had
been issued by the OCC as a result of trades on that Exchange would continue to
be exercisable in accordance with their terms.
 
     A Fund may write options in connection with buy-and-write transactions. In
other words, a Fund may buy a security and then write a call option against that
security. The exercise price of such call will depend upon the expected price
movement of the underlying security. The exercise price of a call option may be
below ("in-the-money"), equal to ("at-the-money") or above ("out-of-the-money")
the current value of the underlying security at the time the option is written.
Buy-and-write transactions using in-the-money call options may be used when it
is expected that the price of the underlying security will remain flat or
decline moderately during the option period. Buy-and-write transactions using
at-the-money call options may be used when it is expected that the price of the
underlying security will remain fixed or advance moderately during the option
period. Buy-and-write transactions using out-of-the-money call options may be
used when it is expected that the premiums received from writing the call option
plus the appreciation in the market price of the underlying security up to the
exercise price will be greater than the appreciation in the price of the
underlying security alone. If the call options are exercised in such
transactions, a Fund's maximum gain will be the premium received by it for
writing the option, adjusted upwards or downwards by the difference between that
Fund's purchase price of the security and the exercise price. If the options are
not exercised and the price of the underlying security declines, the amount of
such decline will be offset by the amount of premium received.
 
     The writing of covered put options is similar in terms of risk and return
characteristics to buy-and-write transactions. If the market price of the
underlying security rises or otherwise is above the exercise price, the put
option will expire worthless and a Fund's gain will be limited to the premium
received. If the market price of the underlying security declines or otherwise
is below the exercise price, a Fund may elect to close the position or take
delivery of the security at the exercise price and that Fund's return will be
the premium received from the put options minus the amount by which the market
price of the security is below the exercise price.
 
     A Fund may buy put options to hedge against a decline in the value of its
portfolio. By using put options in this way, a Fund will reduce any profit it
might otherwise have realized in the underlying security by the amount of the
premium paid for the put option and by transaction costs.
 
     A Fund may buy call options to hedge against an increase in the price of
securities that it may buy in the future. The premium paid for the call option
plus any transaction costs will reduce the benefit, if any, realized by such
Fund upon exercise of the option, and, unless the price of the underlying
security rises sufficiently, the option may expire worthless to that Fund.
 
     EURODOLLAR INSTRUMENTS. A Fund may make investments in Eurodollar
instruments. Eurodollar instruments are U.S. dollar-denominated futures
contracts or options thereon which are linked to the London Interbank Offered
Rate ("LIBOR"), although foreign currency-denominated instruments are available
from time to time. Eurodollar futures contracts enable purchasers to obtain a
fixed rate for the lending of funds and sellers to obtain a fixed rate for
borrowings. A Fund might use Eurodollar futures
 
                                       23
<PAGE>   
 
contracts and options thereon to hedge against changes in LIBOR, to which many
interest rate swaps and fixed-income instruments are linked.
 
     SWAPS AND SWAP-RELATED PRODUCTS. A Fund may enter into interest rate swaps,
caps and floors on either an asset-based or liability-based basis, depending
upon whether it is hedging its assets or its liabilities, and will usually enter
into interest rate swaps on a net basis (i.e., the two payment streams are
netted out, with a Fund receiving or paying, as the case may be, only the net
amount of the two payments). The net amount of the excess, if any, of a Fund's
obligations over its entitlement with respect to each interest rate swap will be
calculated on a daily basis and an amount of cash or other liquid assets having
an aggregate net asset value at least equal to the accrued excess will be
maintained in a segregated account by the Funds' custodian. If a Fund enters
into an interest rate swap on other than a net basis, it would maintain a
segregated account in the full amount accrued on a daily basis of its
obligations with respect to the swap. A Fund will not enter into any interest
rate swap, cap or floor transaction unless the unsecured senior debt or the
claims-paying ability of the other party thereto is rated in one of the three
highest rating categories of at least one NRSRO at the time of entering into
such transaction. Janus Capital will monitor the creditworthiness of all
counterparties on an ongoing basis. If there is a default by the other party to
such a transaction, a Fund will have contractual remedies pursuant to the
agreements related to the transaction.
 
     The swap market has grown substantially in recent years with a large number
of banks and investment banking firms acting both as principals and as agents
utilizing standardized swap documentation. Janus Capital has determined that, as
a result, the swap market has become relatively liquid. Caps and floors are more
recent innovations for which standardized documentation has not yet been
developed and, accordingly, they are less liquid than swaps. To the extent a
Fund sells (i.e., writes) caps and floors, it will segregate cash or other
liquid assets having an aggregate net asset value at least equal to the full
amount, accrued on a daily basis, of its obligations with respect to any caps or
floors.
 
     There is no limit on the amount of interest rate swap transactions that may
be entered into by a Fund. These transactions may in some instances involve the
delivery of securities or other underlying assets by a Fund or its counterparty
to collateralize obligations under the swap. Under the documentation currently
used in those markets, the risk of loss with respect to interest rate swaps is
limited to the net amount of the payments that a Fund is contractually obligated
to make. If the other party to an interest rate swap that is not collateralized
defaults, a Fund would risk the loss of the net amount of the payments that it
contractually is entitled to receive. A Fund may buy and sell (i.e., write) caps
and floors without limitation, subject to the segregation requirement described
above.
 
     ADDITIONAL RISKS OF OPTIONS ON FOREIGN CURRENCIES, FORWARD CONTRACTS AND
FOREIGN INSTRUMENTS. Unlike transactions entered into by the Funds in futures
contracts, options on foreign currencies and forward contracts are not traded on
contract markets regulated by the CFTC or (with the exception of certain foreign
currency options) by the SEC. To the contrary, such instruments are traded
through financial institutions acting as market-makers, although foreign
currency options are also traded on certain Exchanges, such as the Philadelphia
Stock Exchange and the Chicago
 
                                       24
<PAGE>   
 
Board Options Exchange, subject to SEC regulation. Similarly, options on
currencies may be traded over-the-counter. In an over-the-counter trading
environment, many of the protections afforded to Exchange participants will not
be available. For example, there are no daily price fluctuation limits, and
adverse market movements could therefore continue to an unlimited extent over a
period of time. Although the buyer of an option cannot lose more than the amount
of the premium plus related transaction costs, this entire amount could be lost.
Moreover, an option writer and a buyer or seller of futures or forward contracts
could lose amounts substantially in excess of any premium received or initial
margin or collateral posted due to the potential additional margin and
collateral requirements associated with such positions.
 
     Options on foreign currencies traded on Exchanges are within the
jurisdiction of the SEC, as are other securities traded on Exchanges. As a
result, many of the protections provided to traders on organized Exchanges will
be available with respect to such transactions. In particular, all foreign
currency option positions entered into on an Exchange are cleared and guaranteed
by the OCC, thereby reducing the risk of counterparty default. Further, a liquid
secondary market in options traded on an Exchange may be more readily available
than in the over-the-counter market, potentially permitting a Fund to liquidate
open positions at a profit prior to exercise or expiration, or to limit losses
in the event of adverse market movements.
 
     The purchase and sale of exchange-traded foreign currency options, however,
is subject to the risks of the availability of a liquid secondary market
described above, as well as the risks regarding adverse market movements,
margining of options written, the nature of the foreign currency market,
possible intervention by governmental authorities and the effects of other
political and economic events. In addition, exchange-traded options on foreign
currencies involve certain risks not presented by the over-the-counter market.
For example, exercise and settlement of such options must be made exclusively
through the OCC, which has established banking relationships in applicable
foreign countries for this purpose. As a result, the OCC may, if it determines
that foreign governmental restrictions or taxes would prevent the orderly
settlement of foreign currency option exercises, or would result in undue
burdens on the OCC or its clearing member, impose special procedures on exercise
and settlement, such as technical changes in the mechanics of delivery of
currency, the fixing of dollar settlement prices or prohibitions on exercise.
 
     In addition, options on U.S. government securities, futures contracts,
options on futures contracts, forward contracts and options on foreign
currencies may be traded on foreign exchanges and over-the-counter in foreign
countries. Such transactions are subject to the risk of governmental actions
affecting trading in or the prices of foreign currencies or securities. The
value of such positions also could be adversely affected by (i) other complex
foreign political and economic factors, (ii) lesser availability than in the
United States of data on which to make trading decisions, (iii) delays in a
Fund's ability to act upon economic events occurring in foreign markets during
non-business hours in the United States, (iv) the imposition of different
exercise and settlement terms and procedures and margin requirements than in the
United States, and (v) low trading volume.
 
                                       25
<PAGE>   
 
   
                               INVESTMENT ADVISER
    
 
     As stated in the Prospectus, each Fund has an Investment Advisory Agreement
with Janus Capital, 100 Fillmore Street, Denver, Colorado 80206-4928. Each
Advisory Agreement provides that Janus Capital will furnish continuous advice
and recommendations concerning the Funds' investments, provide office space for
the Funds, and pay the salaries, fees and expenses of all Fund officers and of
those Trustees who are affiliated with Janus Capital. Janus Capital also may
make payments to selected broker-dealer firms or institutions which perform
recordkeeping or other services with respect to shareholder accounts. The
minimum aggregate size required for eligibility for such payments, and the
factors in selecting the broker-dealer firms and institutions to which they will
be made, are determined from time to time by Janus Capital. Janus Capital is
also authorized to perform the management and administrative services necessary
for the operation of the Funds.
 
     The Funds pay custodian and transfer agent fees and expenses, brokerage
commissions and dealer spreads and other expenses in connection with the
execution of portfolio transactions, legal and accounting expenses, interest and
taxes, registration fees, expenses of shareholders' meetings and reports to
shareholders, fees and expenses of Trustees who are not affiliated with Janus
Capital, costs of preparing, printing and mailing the Funds' Prospectuses and
SAI to current shareholders, and other costs of complying with applicable laws
regulating the sale of Fund shares. Pursuant to the Advisory Agreements, Janus
Capital furnishes certain other services, including net asset value
determination and fund accounting, recordkeeping, and blue sky registration and
monitoring services, for which the Funds may reimburse Janus Capital for its
costs.
 
   
     Janus Fund, Janus Enterprise Fund, Janus Mercury Fund, Janus Olympus Fund,
Janus Overseas Fund, Janus Special Situations Fund, Janus Twenty Fund, Janus
Worldwide Fund, Janus Balanced Fund, Janus Equity Income Fund and Janus Growth
and Income Fund have each agreed to compensate Janus Capital for its services by
the monthly payment of a fee at the annual rate of 0.75% of the first $300
million of the average daily net assets of each Fund, 0.70% of the next $200
million of the average daily net assets of each Fund and 0.65% on the average
daily net assets of each Fund in excess of $500 million.
    
 
   
     Janus High Yield Fund has agreed to compensate Janus Capital for its
services by the monthly payment of a fee at the annual rate of 0.75% of the
first $300 million of average daily net assets of the Fund and 0.65% of the
average daily net assets in excess of $300 million. Janus Flexible Income Fund
and Janus Short-Term Bond Fund have each agreed to compensate Janus Capital for
its services by the monthly payment of a fee at the annual rate of 0.65% of the
first $300 million of the average daily net assets of the Fund, plus 0.55% of
the average daily net assets of the Fund in excess of $300 million. Janus
Federal Tax-Exempt Fund has agreed to compensate Janus Capital for its services
by the monthly payment of a fee at the annual rate of 0.60% of the first $300
million of average daily net assets of the Fund and 0.55% of the average daily
net assets in excess of $300 million. Janus Capital has agreed to waive the
advisory fee payable by any of these Funds in an amount equal to the amount, if
any, that such Fund's normal operating expenses chargeable to its income account
in any fiscal year, including the investment advisory fee but excluding
brokerage commissions, interest, taxes and
    
 
                                       26
<PAGE>   

   
extraordinary expenses, exceed 1% of the average daily net assets for a fiscal
year for Janus Flexible Income Fund and Janus High-Yield Fund and 0.65% of the
average daily net assets for a fiscal year for Janus Short-Term Bond Fund and
Janus Federal Tax-Exempt Fund.
    

     The following table summarizes the advisory fees paid by the Funds and any
advisory fee waivers for the last three fiscal periods of each Fund. The
information below is for fiscal years ended October 31.

   
<TABLE>
<CAPTION>
                                           1996                      1995
                                 ------------------------   ------------------------
     Fund Name          1997+    Advisory Fees    Waiver    Advisory Fees    Waiver
- ------------------------------------------------------------------------------------
<S>                     <C>      <C>             <C>        <C>             <C>
Janus Fund              $        $89,848,418            -   $69,101,695            -
Janus Enterprise Fund   $        $ 4,348,549            -   $ 3,078,635            -
Janus Mercury Fund      $        $12,407,830            -   $ 7,719,633            -
Janus Olympus Fund      $        $ 1,783,296(3)         -           N/A          N/A
Janus Overseas Fund     $        $ 2,528,345            -   $   657,146            -
Janus Special
  Situations Fund       $    (4)         N/A            -           N/A          N/A
Janus Twenty Fund       $        $22,477,667            -   $18,127,825            -
Janus Worldwide Fund    $        $19,645,721            -   $11,013,534            -
Janus Balanced Fund     $        $ 1,264,551            -   $   879,437            -
Janus Equity Income
  Fund                  $        $    71,858(2)         -           N/A          N/A
Janus Growth and Income
  Fund                  $        $ 5,501,734            -   $ 3,703,827            -
Janus Flexible Income
  Fund                  $        $ 3,620,317            -   $ 2,775,005            -
Janus High-Yield Fund   $        $   556,207(3)   $122,504          N/A          N/A
Janus Federal
  Tax-Exempt Fund       $        $   217,873      $167,598  $   175,910(1)  $175,910
Janus Short-Term Bond
  Fund                  $        $   274,319      $238,092  $   307,992     $268,791
- ------------------------------------------------------------------------------------
</TABLE>
    

   
(1) Fee waiver by Janus Capital exceeded the advisory fee.
    
   
(2) June 28, 1996 (inception) to October 31, 1996.
    
   
(3) December 29, 1995 (inception) to October 31, 1996.
    
   
(4) December 31, 1996 (inception) to October 31, 1997.
    
   
+ [To be filed by Amendment]
    

   
     The Advisory Agreement for each of the Funds is dated July 1, 1997. Each
Advisory Agreement will continue in effect until July 1, 1998, and thereafter
from year to year so long as such continuance is approved annually by a majority
of the Funds' Trustees who are not parties to the Advisory Agreements or
interested persons of any such party, and by either a majority of the
outstanding voting shares or the Trustees of the Funds. Each Advisory Agreement
(i) may be terminated without the payment of any penalty by any Fund or Janus
Capital on 60 days' written notice; (ii) terminates automatically in the event
of its assignment; and (iii) generally, may not be amended without the approval
by vote of a majority of the Trustees of the affected Fund, including the
Trustees who are not interested persons of that Fund or Janus Capital and, to
the extent required by the 1940 Act, the vote of a majority of the outstanding
voting securities of that Fund.
    

     Janus Capital also performs investment advisory services for other mutual
funds, and for individual, charitable, corporate and retirement accounts.
Investment decisions for each account managed by Janus Capital, including the
Funds, are made independently from those for any other account that is or may in
the future become managed by Janus

                                       27
<PAGE>   
 
Capital or its affiliates. If, however, a number of accounts managed by Janus
Capital are contemporaneously engaged in the purchase or sale of the same
security, the orders may be aggregated and/or the transactions may be averaged
as to price and allocated equitably to each account. In some cases, this policy
might adversely affect the price paid or received by an account or the size of
the position obtained or liquidated for an account. Pursuant to an exemptive
order granted by the SEC, the Funds and other funds advised by Janus Capital may
also transfer daily uninvested cash balances into one or more joint trading
accounts. Assets in the joint trading accounts are invested in money market
instruments and the proceeds are allocated to the participating funds on a pro
rata basis.
 
     Each account managed by Janus Capital has its own investment objective and
policies and is managed accordingly by a particular portfolio manager or team of
portfolio managers. As a result, from time to time two or more different managed
accounts may pursue divergent investment strategies with respect to investments
or categories of investments.
 
   
     As indicated in the Prospectuses, Janus Capital does not permit the Funds'
portfolio managers to purchase and sell securities for their own accounts except
under the limited exceptions contained in Janus Capital's policy regarding
personal investing by directors/Trustees, officers and employees of Janus
Capital and the Trust. The policy requires investment personnel and officers of
Janus Capital, inside directors/Trustees of Janus Capital and the Funds and
other designated persons deemed to have access to current trading information to
pre-clear all transactions in securities not otherwise exempt under the policy.
Requests for trading authority will be denied when, among other reasons, the
proposed personal transaction would be contrary to the provisions of the policy
or would be deemed to adversely affect any transaction then known to be under
consideration for or to have been effected on behalf of any client account,
including the Funds.
    
 
   
     In addition to the pre-clearance requirement described above, the policy
subjects investment personnel, officers and directors/Trustees of Janus Capital
and the Trust to various trading restrictions and reporting obligations. All
reportable transactions are reviewed for compliance with Janus Capital's policy.
Those persons also may be required under certain circumstances to forfeit their
profits made from personal trading.
    
 
     The provisions of the policy are administered by and subject to exceptions
authorized by Janus Capital.
 
     Kansas City Southern Industries, Inc., a publicly traded holding company
whose primary subsidiaries are engaged in transportation, information processing
and financial services ("KCSI"), owns approximately 83% of Janus Capital. Thomas
H. Bailey, the President and Chairman of the Board of Janus Capital, owns
approximately 12% of its voting stock and, by agreement with KCSI, selects a
majority of Janus Capital's Board.
 
                                       28
<PAGE>   
 
                           CUSTODIAN, TRANSFER AGENT
                            AND CERTAIN AFFILIATIONS
 
     State Street Bank and Trust Company ("State Street"), P.O. Box 0351,
Boston, Massachusetts 02117-0351 is the custodian of the domestic securities and
cash of the Fund. State Street and the foreign subcustodians selected by it and
approved by the Trustees, have custody of the assets of the Funds held outside
the U.S. and cash incidental thereto. The custodian and subcustodians hold the
Funds' assets in safekeeping and collect and remit the income thereon, subject
to the instructions of each Fund.
 
   
     Janus Service Corporation ("Janus Service"), P.O. Box 173375, Denver,
Colorado 80217-3375, a wholly-owned subsidiary of Janus Capital, is the Funds'
transfer agent. In addition, Janus Service provides certain other
administrative, recordkeeping and shareholder relations services to the Funds.
For transfer agency and other services, Janus Service receives a fee calculated
at an annual rate of 0.16% of average net assets of each Fund and, in addition,
$4 per open shareholder account for all of the Funds except Janus Fund. In
addition, the Funds pay DST Systems, Inc. ("DST"), a subsidiary of KCSI, license
fees at the rate of $3.06 per shareholder account for the growth and combination
funds and $3.98 per shareholder account for the fixed-income funds for the use
of DST's shareholder accounting system. The Funds also pay DST $1.10 per closed
shareholder account. The Funds pay DST for the use of its portfolio and fund
accounting system a monthly base fee of $250 to $1,250 per month based on the
number of Janus funds using the system and an asset charge of $1 per million
dollars of net assets (not to exceed $500 per month). In addition, the Funds pay
DST postage and forms costs of a DST affiliate incurred in mailing Fund
shareholder transaction confirmations.
    
 
   
     The Trustees have authorized the Funds to use another affiliate of DST as
introducing broker for certain Fund portfolio transactions as a means to reduce
Fund expenses through credits against the charges of DST and its affiliates with
regard to commissions earned by such affiliate. See "Portfolio Transactions and
Brokerage."
    
 
     Janus Distributors, Inc. ("Janus Distributors"), 100 Fillmore Street,
Denver, Colorado 80206-4928, a wholly-owned subsidiary of Janus Capital, is a
distributor of the Funds. Janus Distributors is registered as a broker-dealer
under the Securities Exchange Act of 1934 (the "Exchange Act") and is a member
of the National Association of Securities Dealers, Inc. Janus Distributors acts
as the agent of the Funds in connection with the sale of their shares in all
states in which the shares are registered and in which Janus Distributors is
qualified as a broker-dealer. Under the Distribution Agreement, Janus
Distributors continuously offers the Funds' shares and accepts orders at net
asset value. No sales charges are paid by investors. Promotional expenses in
connection with offers and sales of shares are paid by Janus Capital.
 
                                       29
<PAGE>   
 
                             PORTFOLIO TRANSACTIONS
                                 AND BROKERAGE
 
     Decisions as to the assignment of portfolio business for the Funds and
negotiation of its commission rates are made by Janus Capital whose policy is to
obtain the "best execution" (prompt and reliable execution at the most favorable
security price) of all portfolio transactions. The Funds may trade foreign
securities in foreign countries because the best available market for these
securities is often on foreign exchanges. In transactions on foreign stock
exchanges, brokers' commissions are frequently fixed and are often higher than
in the United States, where commissions are negotiated.
 
     In selecting brokers and dealers and in negotiating commissions, Janus
Capital considers a number of factors, including but not limited to: Janus
Capital's knowledge of currently available negotiated commission rates or prices
of securities currently available and other current transaction costs; the
nature of the security being traded; the size and type of the transaction; the
nature and character of the markets for the security to be purchased or sold;
the desired timing of the trade; the activity existing and expected in the
market for the particular security; confidentiality; the quality of the
execution, clearance and settlement services; financial stability of the broker
or dealer; the existence of actual or apparent operational problems of any
broker or dealer; rebates of commissions by a broker to a Fund or to a third
party service provider to the Fund to pay Fund expenses; and research products
or services provided. In recognition of the value of the foregoing factors,
Janus Capital may place portfolio transactions with a broker or dealer with whom
it has negotiated a commission that is in excess of the commission another
broker or dealer would have charged for effecting that transaction if Janus
Capital determines in good faith that such amount of commission was reasonable
in relation to the value of the brokerage and research provided by such broker
or dealer viewed in terms of either that particular transaction or of the
overall responsibilities of Janus Capital. Research may include furnishing
advice, either directly or through publications or writings, as to the value of
securities, the advisability of purchasing or selling specific securities and
the availability of securities or purchasers or sellers of securities;
furnishing seminars, information, analyses and reports concerning issuers,
industries, securities, trading markets and methods, legislative developments,
changes in accounting practices, economic factors and trends and portfolio
strategy; access to research analysts, corporate management personnel, industry
experts, economists and government officials; comparative performance evaluation
and technical measurement services and quotation services, and products and
other services (such as third party publications, reports and analyses, and
computer and electronic access, equipment, software, information and accessories
that deliver, process or otherwise utilize information, including the research
described above) that assist Janus Capital in carrying out its responsibilities.
Research received from brokers or dealers is supplemental to Janus Capital's own
research efforts. Most brokers and dealers used by Janus Capital provide
research and other services described above.
 
                                       30
<PAGE>   
 
   
     For the year ended October 31, 1997, the total brokerage commissions paid
by the Funds to brokers and dealers in transactions identified for execution
primarily on the basis of research and other services provided to the Funds are
summarized below:
    
 
   
     [To be filed by Amendment]
    
 
   
<TABLE>
<CAPTION>
                Fund Name                  Commissions    Transactions
- ------------------------------------------------------------------------
<S>                                        <C>           <C>
Janus Fund                                 $             $
Janus Enterprise Fund                      $             $
Janus Mercury Fund                         $             $
Janus Olympus Fund                         $             $
Janus Overseas Fund                        $             $
Janus Special Situations Fund              $             $
Janus Twenty Fund                          $             $
Janus Worldwide Fund                       $             $
Janus Balanced Fund                        $             $
Janus Equity Income Fund                   $             $
Janus Growth and Income Fund               $             $
Janus Flexible Income Fund(1)              $             $
Janus High-Yield Fund(1)                   $             $
- ------------------------------------------------------------------------
</TABLE>
    
 
(1) Most of the securities transactions for this Fund involved dealers acting as
    principal.
Note: Funds that are not included in the table did not pay any commissions
      related to research for the stated period.
 
     Janus Capital may use research products and services in servicing other
accounts in addition to the Funds. If Janus Capital determines that any research
product or service has a mixed use, such that it also serves functions that do
not assist in the investment decision-making process, Janus Capital may allocate
the costs of such service or product accordingly. Only that portion of the
product or service that Janus Capital determines will assist it in the
investment decision-making process may be paid for in brokerage commission
dollars. Such allocation may create a conflict of interest for Janus Capital.
 
     Janus Capital does not enter into agreements with any brokers regarding the
placement of securities transactions because of the research services they
provide. It does, however, have an internal procedure for allocating
transactions in a manner consistent with its execution policy to brokers that it
has identified as providing superior executions and research, research-related
products or services which benefit its advisory clients, including the Funds.
Research products and services incidental to effecting securities transactions
furnished by brokers or dealers may be used in servicing any or all of Janus
Capital's clients and such research may not necessarily be used by Janus Capital
in connection with the accounts which paid commissions to the broker-dealer
providing such research products and services.
 
     Janus Capital may consider sales of Fund shares by a broker-dealer or the
recommendation of a broker-dealer to its customers that they purchase Fund
shares as a factor in the selection of broker-dealers to execute Fund portfolio
transactions. Janus Capital may also consider payments made by brokers effecting
transactions for a Fund i) to the Fund or ii) to other persons on behalf of the
Fund for services provided to the Fund for which it would be obligated to pay.
In placing portfolio business with such broker-dealers, Janus Capital will seek
the best execution of each transaction.
 
                                       31
<PAGE>   
 
     When the Funds purchase or sell a security in the over-the-counter market,
the transaction takes place directly with a principal market-maker, without the
use of a broker, except in those circumstances where in the opinion of Janus
Capital better prices and executions will be achieved through the use of a
broker.
 
     The Funds' Trustees have authorized Janus Capital to place transactions
with DST Securities, Inc. ("DSTS"), a wholly-owned broker-dealer subsidiary of
DST. Janus Capital may do so if it reasonably believes that the quality of the
transaction and the associated commission are fair and reasonable and if,
overall, the associated transaction costs, net of any credits described above
under "Custodian, Transfer Agent and Certain Affiliations," are lower than those
that would otherwise be incurred.
 
     The following table lists the total amount of brokerage commissions paid by
each Fund for the fiscal periods ending on October 31st of each year:
 
   
<TABLE>
<CAPTION>
               Fund Name                     1997+         1996          1995
- ---------------------------------------------------------------------------------
<S>                                       <C>           <C>           <C>
Janus Fund                                $             $29,000,380   $26,219,202
Janus Enterprise Fund                     $             $ 1,188,690   $ 2,084,312
Janus Mercury Fund                        $             $ 5,337,713   $ 5,712,916
Janus Olympus Fund                        $             $   713,190(2)          -
Janus Overseas Fund                       $             $ 1,900,947   $   568,384
Janus Special Situations Fund             $         (3)           -             -
Janus Twenty Fund                         $             $ 7,346,447   $ 7,647,982
Janus Worldwide Fund                      $             $10,947,924   $ 7,493,192
Janus Balanced Fund                       $             $    64,843   $   305,855
Janus Equity Income Fund                  $             $    63,683(1)          -
Janus Growth and Income Fund              $             $ 1,985,334   $ 1,498,178
Janus Flexible Income Fund                $             $    15,386   $    35,138
Janus High-Yield Fund                     $             $    39,981(2)          -
Janus Short-Term Bond Fund                $                       -   $     6,548
- ---------------------------------------------------------------------------------
</TABLE>
    
 
   
(1) June 28, 1996 (inception) to October 31, 1996.
    
   
(2) December 29, 1995 (inception) to October 31, 1996.
    
   
(3) December 31, 1996 (inception) to October 31, 1997.
    
Note: Funds that are not included in the table did not pay brokerage commissions
because securities transactions for such Funds involved dealers acting as
principals.
   
 + [To be filed by Amendment]
    
 
                                       32
<PAGE>   
 
     Included in such brokerage commissions are the following amounts paid to
DSTS, which served to reduce each Fund's out-of-pocket expenses as follows:
 
   
<TABLE>
<CAPTION>
                             Commission Paid
                             through DSTS for
                             the Period Ended     Reduction
                               October 31,            of         % of Total     % of Total
        Fund Name                 1997*           Expenses*     Commissions+   Transactions
- -------------------------------------------------------------------------------------------
<S>                         <C>                  <C>            <C>            <C>
Janus Fund                       $                 $                    %              %
Janus Enterprise Fund            $                 $                    %              %
Janus Mercury Fund               $                 $                    %              %
Janus Olympus Fund               $                 $                    %              %
Janus Overseas Fund              $                 $                    %              %
Janus Special Situations
  Fund                           $       (1)       $
Janus Twenty Fund                $                 $                    %              %
Janus Worldwide Fund             $                 $                    %              %
Janus Balanced Fund              $                 $                    %              %
Janus Equity Income Fund         $                 $                    %              %
Janus Growth and Income
  Fund                           $                 $                    %              %
- -------------------------------------------------------------------------------------------
</TABLE>
    
 
   
(1) December 31, 1996 (inception) to October 31, 1997.
    
 
   
<TABLE>
<CAPTION>
                        Commission Paid                          Commission
                        through DSTS for                     Paid through DSTS
                        the Period Ended     Reduction         for the Period        Reduction
                          October 31,            of                Ended                 of
      Fund Name              1996*           Expenses*       October 31, 1995*       Expenses*
- ----------------------------------------------------------------------------------------------
<S>                    <C>                  <C>            <C>                      <C>
Janus Fund                  $470,414          $352,810           $1,125,368           $844,026
Janus Enterprise Fund       $ 11,030          $  8,273           $   96,932           $ 72,699
Janus Mercury Fund          $ 88,645          $ 66,483           $  171,777           $128,833
Janus Olympus Fund          $  1,117(2)       $    838                   --                 --
Janus Overseas Fund         $  5,123          $  3,842           $    2,783           $  2,087
Janus Twenty Fund           $183,255          $137,441           $  378,575           $283,931
Janus Worldwide Fund        $104,173          $ 78,130           $  164,193           $123,145
Janus Balanced Fund         $  9,591          $  7,194           $    9,143           $  6,857
Janus Equity Income
  Fund                      $     83(1)       $     62                   --                 --
Janus Growth and
  Income Fund               $ 79,006          $ 59,254           $   98,373           $ 73,780
- ----------------------------------------------------------------------------------------------
</TABLE>
    
 
* The difference between commissions paid through DSTS and expenses reduced
  constitute commissions paid to an unaffiliated clearing broker.
+ Differences in the percentage of total commissions versus the percentage of
  total transactions is due, in part, to variations among share prices and
  number of shares traded, while average price per share commission rates were
  substantially the same.
(1) June 28, 1996 (inception) to October 31, 1996.
(2) December 29, 1995 (inception) to October 31, 1996.
   
Note: Funds that did not execute trades with DSTS during the stated periods are
not included in the table.
    
 
                                       33
<PAGE>   
 
   
     As of October 31, 1997, certain Funds owned securities of their regular
broker-dealers (or parents), as shown below:
    
 
<TABLE>
<CAPTION>
                                                                  Value of
                                        Name of                  Securities
       Fund Name                     Broker-Dealer                 Owned
- ----------------------------------------------------------------------------
<S>                      <C>                                    <C>
[To be filed by Amendment]
</TABLE>
 
                             OFFICERS AND TRUSTEES
 
     The following are the names of the Trustees and officers of the Trust,
together with a brief description of their principal occupations during the last
five years. In August 1992, Janus Venture Fund, Inc. and Janus Twenty Fund, Inc.
(both separate Maryland corporations) and the Janus Income Series (a
Massachusetts business trust comprised of Janus Flexible Income Fund series)
were reorganized into separate series of the Trust. In general, all references
to Trust offices in this section include comparable offices with the respective
predecessor funds, unless a Trust office was filled subsequent to the
reorganization.
 
Thomas H. Bailey*# - Trustee, Chairman and President
100 Fillmore Street
Denver, CO 80206-4928
     Trustee, Chairman and President of Janus Aspen Series. Chairman, Chief
     Executive Officer, Director and President of Janus Capital. Chairman and
     Director of IDEX Management, Inc., Largo, Florida (50% subsidiary of Janus
     Capital and investment adviser to a group of mutual funds) ("IDEX").
 
   
David J. Corkins*+ - Executive Vice President
    
   
100 Fillmore Street
    
   
Denver, CO 80206-4928
    
   
     Executive Vice President and Portfolio Manager of Janus Growth and Income
     Fund. Executive Vice President of Janus Aspen Series. Formerly, research
     analyst and assistant portfolio manager at Janus Capital (1995-1997).
     Formerly, Chief Financial Officer of Chase U.S. Consumer Services, Inc., a
     Chase Manhattan mortgage business (1993-1995).
    
 
James P. Craig, III*# - Trustee and Executive Vice President
100 Fillmore Street
Denver, CO 80206-4928
   
     Trustee and Executive Vice President of Janus Aspen Series. Chief
     Investment Officer, Vice President and Director of Janus Capital. Executive
     Vice President and Portfolio Manager of Janus Fund. Executive Vice
     President and Co-Manager of Janus Venture Fund.
    
 
- --------------------------------------------------------------------------------
*Interested person of the Trust and of Janus Capital.
#Member of the Trust's Executive Committee.
   
+Mr. Corkins is related by marriage to Mr. Lammert.
    
 
                                       34
<PAGE>   
 
   
David C. Decker* - Executive Vice President
    
   
100 Fillmore Street
    
   
Denver, CO 80206-4928
    
   
     Executive Vice President and Portfolio Manager of Janus Special Situations
     Fund. Assistant Portfolio Manager of Janus Fund. Formerly, research analyst
     at Janus Capital (1992-1996).
    
 
James P. Goff* - Executive Vice President
100 Fillmore Street
Denver, CO 80206-4928
   
     Executive Vice President and Portfolio Manager of Janus Enterprise Fund.
     Executive Vice President of Janus Aspen Series. Vice President of Janus
     Capital. Formerly, Executive Vice President and Portfolio Manager of Janus
     Venture Fund (December 1993 to February 1997).
    
 
   
Warren B. Lammert*+ - Executive Vice President
    
100 Fillmore Street
Denver, CO 80206-4928
   
     Executive Vice President and Portfolio Manager of Janus Mercury Fund. Vice
     President of Janus Capital. Formerly, Executive Vice President and
     Portfolio Manager of Janus Venture Fund (December 1993-December 1996) and
     Janus Balanced Fund (September 1992-December 1993).
    
 
Ronald V. Speaker* - Executive Vice President
100 Fillmore Street
Denver, CO 80206-4928
   
     Executive Vice President and Co-Manager of Janus Flexible Income Fund and
     Janus High-Yield Fund. Executive Vice President of Janus Aspen Series. Vice
     President of Janus Capital. Formerly, Portfolio Manager of Janus Short-Term
     Bond Fund (September 1992-December 1995) and Janus Federal Tax-Exempt Fund
     (May 1993-December 1995).
    
 
   
Helen Young Hayes*++ - Executive Vice President
    
100 Fillmore Street
Denver, CO 80206-4928
     Executive Vice President and Portfolio Manager of Janus Worldwide Fund and
     Janus Overseas Fund. Executive Vice President of Janus Aspen Series. Vice
     President of Janus Capital. Formerly securities analyst at Janus Capital
     (1987 to 1993).
 
Blaine P. Rollins* - Executive Vice President
100 Fillmore Street
Denver, CO 80206-4928
     Executive Vice President and Portfolio Manager of Janus Balanced Fund and
     Janus Equity Income Fund. Assistant Portfolio Manager of Janus Fund.
     Executive Vice President of Janus Aspen Series. Formerly, fixed-income
     trader and equity securities analyst at Janus Capital (1990-1995).
 
- --------------------------------------------------------------------------------
*Interested person of the Trust and of Janus Capital.
   
+Mr. Lammert and Mr. Corkins are related by marriage.
    
   
++Ms. Hayes is Ms. Young's sister.
    
 
                                       35
<PAGE>   
 
Sandy R. Rufenacht* - Executive Vice President
100 Fillmore Street
Denver, CO 80206-4928
     Executive Vice President and Portfolio Manager of Janus Short-Term Bond
     Fund and Executive Vice President and Co-Manager of Janus Flexible Income
     Fund and Janus High-Yield Fund. Executive Vice President of Janus Aspen
     Series. Formerly senior accountant, fixed-income trader and fixed-income
     research analyst at Janus Capital (1990-1995).
 
Scott W. Schoelzel* - Executive Vice President
100 Fillmore Street
Denver, CO 80206-4928
   
     Executive Vice President and Portfolio Manager of Janus Twenty Fund. Vice
     President of Janus Capital. Formerly (1995-1997), Executive Vice President
     and Portfolio Manager of Janus Olympus Fund. Formerly (January 1994-June
     1995), Vice President of Investments at Janus Capital. Formerly (1991-1993)
     a Portfolio Manager with Founders Asset Management, Denver, Colorado.
    
 
Darrell W. Watters* - Executive Vice President
100 Fillmore Street
Denver, CO 80206-4928
   
     Executive Vice President and Portfolio Manager of Janus Federal Tax-Exempt
     Fund. Executive Vice President of Janus Aspen Series. Formerly, municipal
     bond trader and research analyst at Janus Capital (1993-1995).
    
 
   
Claire Young*+ - Executive Vice President
    
   
100 Fillmore Street
    
   
Denver, CO 80206-4928
    
   
     Executive Vice President and Portfolio Manager of Janus Olympus Fund.
     Formerly, research analyst and assistant portfolio manager at Janus Capital
     (1992-1997).
    
 
   
Steven R. Goodbarn* - Vice President and Chief Financial Officer
    
100 Fillmore Street
Denver, CO 80206-4928
   
     Vice President and Chief Financial Officer of Janus Aspen Series. Vice
     President of Finance, Treasurer and Chief Financial Officer of Janus
     Service, Janus Distributors and Janus Capital. Director of IDEX, Janus
     Service and Janus Distributors. Director, Treasurer and Vice President of
     Finance of Janus Capital International Ltd. Formerly (May 1992-January
     1996), Treasurer of Janus Investment Fund and Janus Aspen Series.
    
 
Glenn P. O'Flaherty* - Treasurer and Chief Accounting Officer
100 Fillmore Street
Denver, CO 80206-4928
     Treasurer and Chief Accounting Officer of Janus Aspen Series. Director of
     Fund Accounting of Janus Capital.
 
- --------------------------------------------------------------------------------
*Interested person of the Trust and of Janus Capital.
   
+Ms. Young is Ms. Hayes' sister.
    
 
                                       36
<PAGE>   
 
Kelley Abbott Howes* - Secretary
100 Fillmore Street
Denver, CO 80206-4928
   
     Secretary of Janus Aspen Series. Director and President of Janus
     Distributors. Associate Counsel of Janus Capital. Formerly (1990 to 1994),
     with The Boston Company Advisors, Inc., Boston, Massachusetts (mutual fund
     administration services).
    
 
   
William D. Stewart# - Trustee
    
5330 Sterling Drive
Boulder, CO 80302
   
     Trustee of Janus Aspen Series. President of HPS Division of MKS
     Instruments, Boulder, Colorado (manufacturer of vacuum fittings and
     valves).
    
 
   
Gary O. Loo# - Trustee
    
102 N. Cascade, Suite 500
Colorado Springs, CO 80903
     Trustee of Janus Aspen Series. President and a Director of High Valley
     Group, Inc., Colorado Springs, Colorado (investments).
 
Dennis B. Mullen - Trustee
   
14103 Denver West Parkway
    
   
Golden, CO 80401
    
   
     Trustee of Janus Aspen Series. Chief Financial Officer-Boston Market
     Concepts, Boston Chicken, Inc., Golden, Colorado (restaurant chain).
     Formerly (1993 to 1997), President and Chief Executive Officer of BC
     Northwest, L.P., a franchise of Boston Chicken, Inc., Bellevue, Washington
     (restaurant chain).
    
 
Martin H. Waldinger - Trustee
4940 Sandshore Court
San Diego, CA 92130
   
     Trustee of Janus Aspen Series. Private Consultant. Formerly (1993 to 1996),
     Director of Run Technologies, Inc., a software development firm, San
     Carlos, California. Formerly (1989 to 1993), President and Chief Executive
     Officer of Bridgecliff Management Services, Campbell, California (a
     condominium association management company).
    
 
James T. Rothe - Trustee
102 South Tejon Street, Suite 1100
Colorado Springs, CO 80903
     Trustee of Janus Aspen Series. Professor of Business, University of
     Colorado, Colorado Springs, Colorado. Principal, Phillips-Smith Retail
     Group, Colorado Springs, Colorado (a venture capital firm). Formerly
     (1986-1994), Dean of the College of Business, University of Colorado,
     Colorado Springs, Colorado.
 
- --------------------------------------------------------------------------------
   
*Interested person of the Trust and of Janus Capital.
    
   
#Member of the Trust's Executive Committee.
    
 
                                       37
<PAGE>   
 
     The Trustees are responsible for major decisions relating to each Fund's
objective, policies and techniques. The Trustees also supervise the operation of
the Funds by their officers and review the investment decisions of the officers
although they do not actively participate on a regular basis in making such
decisions.
 
   
     The Trust's Executive Committee shall have and may exercise all the powers
and authority of the Trustees except for matters requiring action by all
Trustees pursuant to the Trust's Bylaws or Agreement and Declaration of Trust
("Declaration of Trust"), Massachusetts law or the 1940 Act.
    
 
   
     The following table shows the aggregate compensation earned by and paid to
each Trustee by the Funds described in this SAI and all funds advised and
sponsored by Janus Capital (collectively, the "Janus Funds") for the periods
indicated. None of the Trustees receive any pension or retirement benefits from
the Funds or the Janus Funds.
    
 
   
<TABLE>
<CAPTION>
                           AGGREGATE COMPENSATION      TOTAL COMPENSATION
                             FROM THE FUNDS FOR     FROM THE JANUS FUNDS FOR
                             FISCAL YEAR ENDED         CALENDAR YEAR ENDED
                              OCTOBER 31, 1997         DECEMBER 31, 1997**
                              [TO BE FILED BY            [TO BE FILED BY
NAME OF PERSON, POSITION         AMENDMENT]                AMENDMENT]
<S>                        <C>                      <C>
- -----------------------------------------------------------------------------
Thomas H. Bailey,
  Chairman*                      $                         $
James P. Craig, III,
  Trustee*                       $                         $
William D. Stewart,
  Trustee                        $                         $
Gary O. Loo, Trustee             $                         $
Dennis B. Mullen, Trustee        $                         $
Martin H. Waldinger,
  Trustee                        $                         $
James T. Rothe, Trustee          $                         $
- -----------------------------------------------------------------------------
</TABLE>
    
 
 * An interested person of the Funds and of Janus Capital. Compensated by Janus
   Capital and not the Funds.
   
** As of December 31, 1997, Janus Funds consisted of two registered investment
   companies comprised of a total of 32 funds.
    
 
                               PURCHASE OF SHARES
 
     As stated in the Prospectus, Janus Distributors is a distributor of the
Funds' shares. Shares of the Funds are sold at the net asset value per share as
determined at the close of the regular trading session of the New York Stock
Exchange (the "NYSE") next occurring after a purchase order is received and
accepted by a Fund. The Shareholder's Manual Section of the Prospectus contains
detailed information about the purchase of shares.
 
NET ASSET VALUE DETERMINATION
   
     As stated in the Prospectus, the net asset value ("NAV") of Fund shares is
determined once each day on which the NYSE is open, at the close of its regular
trading session (normally 4:00 p.m., New York time, Monday through Friday). The
NAV of Fund shares is not determined on days the NYSE is closed (generally, New
Year's Day, Martin Luther King Day, Presidents' Day, Good Friday, Memorial Day,
Independence Day, Labor Day, Thanksgiving and Christmas). The per share NAV of
each Fund is
    
 
                                       38
<PAGE>   
 
   
determined by dividing the total value of a Fund's securities and other assets,
less liabilities, by the total number of shares outstanding. In determining NAV,
securities listed on an Exchange, the NASDAQ National Market and foreign markets
are valued at the closing prices on such markets, or if such price is lacking
for the trading period immediately preceding the time of determination, such
securities are valued at their current bid price. Municipal securities held by
the Funds are traded primarily in the over-the-counter market. Valuations of
such securities are furnished by one or more pricing services employed by the
Funds and are based upon a computerized matrix system or appraisals obtained by
a pricing service, in each case in reliance upon information concerning market
transactions and quotations from recognized municipal securities dealers. Other
securities that are traded on the over-the-counter market are valued at their
closing bid prices. Foreign securities and currencies are converted to U.S.
dollars using the exchange rate in effect at the close of the NYSE. Each Fund
will determine the market value of individual securities held by it, by using
prices provided by one or more professional pricing services which may provide
market prices to other funds, or, as needed, by obtaining market quotations from
independent broker-dealers. Short-term securities maturing within 60 days are
valued on an amortized cost basis. Securities for which quotations are not
readily available, and other assets, are valued at fair values determined in
good faith under procedures established by and under the supervision of the
Trustees.
    
 
     Trading in securities on European and Far Eastern securities exchanges and
over-the-counter markets is normally completed well before the close of business
on each business day in New York (i.e., a day on which the NYSE is open). In
addition, European or Far Eastern securities trading generally or in a
particular country or countries may not take place on all business days in New
York. Furthermore, trading takes place in Japanese markets on certain Saturdays
and in various foreign markets on days which are not business days in New York
and on which a Fund's NAV is not calculated. A Fund calculates its NAV per
share, and therefore effects sales, redemptions and repurchases of its shares,
as of the close of the NYSE once on each day on which the NYSE is open. Such
calculation may not take place contemporaneously with the determination of the
prices of the foreign portfolio securities used in such calculation.
 
REINVESTMENT OF DIVIDENDS AND DISTRIBUTIONS
 
   
     If investors do not elect in writing or by phone to receive their dividends
and distributions in cash, all income dividends and capital gains distributions,
if any, on a Fund's shares are reinvested automatically in additional shares of
that Fund at the NAV determined on the first business day following the record
date. Checks for cash dividends and distributions and confirmations of
reinvestments are usually mailed to shareholders within ten days after the
record date. Any election of the manner in which a shareholder wishes to receive
dividends and distributions (which may be made on the New Account Application
form or by phone) will apply to dividends and distributions the record dates of
which fall on or after the date that a Fund receives such notice. Changes to
distribution options must be received at least three days prior to the record
date to be effective for such date. Investors receiving cash distributions and
dividends may elect in writing or by phone to change back to automatic
reinvestment at any time.
    
 
                                       39
<PAGE>   
 
                              REDEMPTION OF SHARES
 
     Procedures for redemption of shares are set forth in the Shareholder's
Manual section of the Prospectuses. Shares normally will be redeemed for cash,
although each Fund retains the right to redeem its shares in kind under unusual
circumstances, in order to protect the interests of remaining shareholders, by
delivery of securities selected from its assets at its discretion. However, the
Funds are governed by Rule 18f-1 under the 1940 Act, which requires each Fund to
redeem shares solely in cash up to the lesser of $250,000 or 1% of the NAV of
that Fund during any 90-day period for any one shareholder. Should redemptions
by any shareholder exceed such limitation, a Fund will have the option of
redeeming the excess in cash or in kind. If shares are redeemed in kind, the
redeeming shareholder might incur brokerage costs in converting the assets to
cash. The method of valuing securities used to make redemptions in kind will be
the same as the method of valuing portfolio securities described under "Purchase
of Shares -- Net Asset Value Determination" and such valuation will be made as
of the same time the redemption price is determined.
 
     The right to require the Funds to redeem its shares may be suspended, or
the date of payment may be postponed, whenever (1) trading on the NYSE is
restricted, as determined by the SEC, or the NYSE is closed except for holidays
and weekends, (2) the SEC permits such suspension and so orders, or (3) an
emergency exists as determined by the SEC so that disposal of securities or
determination of NAV is not reasonably practicable.
 
                              SHAREHOLDER ACCOUNTS
 
     Detailed information about the general procedures for shareholder accounts
and specific types of accounts is set forth in the Prospectuses. Applications
for specific types of accounts may be obtained by calling the Funds at
1-800-525-3713 or writing to the Funds at P.O. Box 173375, Denver, Colorado
80217-3375.
 
TELEPHONE TRANSACTIONS
     As stated in the Prospectuses, shareholders may initiate a number of
transactions by telephone. The Funds, their transfer agent and their distributor
disclaim responsibility for the authenticity of instructions received by
telephone. Such entities will employ reasonable procedures to confirm that
instructions communicated by telephone are genuine. Such procedures may include,
among others, requiring personal identification prior to acting upon telephone
instructions, providing written confirmation of the transactions and tape
recording telephone conversations.
 
SYSTEMATIC REDEMPTIONS
   
     As stated in the Shareholder's Manual section of the Prospectuses, if you
have a regular account or are eligible for distributions from a retirement plan,
you may establish a systematic redemption option. The payments will be made from
the proceeds of periodic redemptions of shares in the account at the NAV.
Depending on the size or frequency of the disbursements requested, and the
fluctuation in value of a Fund's portfolio, redemptions for the purpose of
making such disbursements may reduce or
    
 
                                       40
<PAGE>   
 
   
even exhaust the shareholder's account. Either an investor or a Fund, by written
notice to the other, may terminate the investor's systematic redemption option
without penalty at any time.
    
 
     Information about requirements to establish a systematic redemption option
may be obtained by writing or calling the Funds at the address or phone number
shown above.
 
   
                             TAX DEFERRED ACCOUNTS
    
 
   
     The Funds offer several different types of tax-deferred accounts that an
investor may establish to invest in Fund shares, depending on rules prescribed
by the Code. Regular and Roth Individual Retirement Accounts ("IRAs") may be
used by most individuals who have taxable compensation. Simplified Employee
Pensions ("SEPs") and Defined Contribution Plans (Profit Sharing or Money
Purchase Pension Plans) may be used by most employers, including corporations,
partnerships and sole proprietors, for the benefit of business owners and their
employees. Education IRAs allow individuals, subject to certain income
limitations, to contribute up to $500 annually on behalf of any child under the
age of 18. In addition, the Funds offer a Section 403(b)(7) Plan for employees
of educational organizations and other qualifying tax-exempt organizations.
Investors should consult their tax advisor or legal counsel before selecting a
tax-deferred account.
    
 
   
     Contributions under Regular and Roth IRAs, Education IRAs, SEPs, Defined
Contribution Plans and Section 403(b)(7) Plans are subject to specific
contribution limitations. Generally, such contributions may be invested at the
direction of the participant. The investment is then held by Investors Fiduciary
Trust Company as custodian. Each participant's account is charged an annual fee
of $12. There is a maximum annual fee of $24 per taxpayer identification number.
The Funds reserve the right to change the amount of this fee or to waive it in
whole or in part for certain types of accounts.
    
 
   
     Distributions from tax-deferred accounts may be subject to ordinary income
tax and may be subject to an additional 10% tax if withdrawn prior to age 59 1/2
or used for a nonqualifying purpose. Additionally, shareholders generally must
start withdrawing retirement plan assets no later than April 1 of the year after
they reach age 70 1/2. Several exceptions to these general rules may apply and
several methods exist to determine the amount and timing of the minimum annual
distribution (if any). Shareholders should consult with their tax advisor or
legal counsel prior to receiving any distribution from any tax-deferred account,
in order to determine the income tax impact of any such distribution.
    
 
   
     To receive additional information about Regular and Roth IRAs, SEPs,
Defined Contribution Plans and Section 403(b)(7) Plans along with the necessary
materials to establish an account, please call the Funds at 1-800-525-3713 or
write to the Funds at P.O. Box 173375, Denver, Colorado 80217-3375. No
contribution to a Regular or Roth IRA, SEP, Defined Contribution Plan or Section
403(b)(7) Plan can be made until the appropriate forms to establish any such
plan have been completed.
    
 
                                       41
<PAGE>   
 
                           INCOME DIVIDENDS, CAPITAL
                              GAINS DISTRIBUTIONS
                                 AND TAX STATUS
 
   
     It is a policy of the Funds to make distributions of substantially all of
their investment income and any net realized capital gains. Any capital gains
realized during each fiscal year ended October 31, as defined by the Code, are
normally declared and payable to shareholders in December. Janus Fund, Janus
Enterprise Fund, Janus Mercury Fund, Janus Olympus Fund, Janus Overseas Fund,
Janus Special Situations Fund, Janus Twenty Fund and Janus Worldwide Fund
declare and make annual distributions of income (if any); Janus Equity Income
Fund, Janus Balanced Fund and Janus Growth and Income Fund declare and make
quarterly distributions of income and Janus Flexible Income Fund, Janus
High-Yield Fund, Janus Federal Tax-Exempt Fund and Janus Short-Term Bond Fund
declare dividends daily and make monthly distributions of income. If a month
begins on a Saturday, Sunday or holiday, dividends for daily dividend Funds for
those days are declared at the end of the preceding month. Janus Federal
Tax-Exempt Fund will use the "average annual method" to determine the designated
percentage of each distribution that is tax-exempt. Under this method, the
percentage of income designated as tax-exempt is based on the percentage of
tax-exempt income earned for each annual period, and may be substantially
different from the Fund's income that was tax-exempt during any monthly period.
The Funds intend to qualify as regulated investment companies by satisfying
certain requirements prescribed by Subchapter M of the Code.
    
 
   
     The Funds may purchase securities of certain foreign corporations
considered to be passive foreign investment companies by the IRS. In order to
avoid taxes and interest that must be paid by the Funds if these instruments are
profitable, the Funds may make various elections permitted by the tax laws.
However, these elections could require that the Funds recognize taxable income,
which in turn must be distributed.
    
 
   
     Some foreign securities purchased by the Funds may be subject to foreign
taxes which could reduce the yield on such securities. The amount of such
foreign taxes is expected to be insignificant. The Funds may from year to year
make the election permitted under section 853 of the Code to pass through such
taxes to shareholders, who will each decide whether to deduct such taxes or
claim a foreign tax credit. If such election is not made, foreign taxes paid or
accrued will represent an expense to each Fund which will reduce its investment
company taxable income.
    
 
   
                             PRINCIPAL SHAREHOLDERS
    
 
   
     [To be filed by Amendment]
    
 
                           MISCELLANEOUS INFORMATION
 
     Each Fund is a series of the Trust, a Massachusetts business trust that was
created on February 11, 1986. The Trust is an open-end management investment
company
 
                                       42
<PAGE>   
 
   
registered under the 1940 Act. As of the date of this SAI, the Trust offers 19
separate series. On June 16, 1986, the Trust assumed all the assets and
liabilities of its predecessor corporation, Janus Fund, Inc., which was
incorporated under the laws of Maryland on September 18, 1968. All references in
this SAI to Janus Fund and all financial and other information about Janus Fund
prior to June 16, 1986, are to the former Janus Fund, Inc.; all references after
June 16, 1986 are to the Janus Fund series of the Trust.
    
 
     On August 7, 1992, in a tax-free reorganization, the Trust assumed all the
assets and liabilities of (i) the Janus Flexible Income Fund series of Janus
Income Series, a separate Massachusetts business trust created on May 28, 1986;
and (ii) Janus Twenty Fund, Inc., a Maryland corporation originally incorporated
as Janus Value Fund in 1984. Shareholders received shares of the series of the
Trust equal both in number and net asset value to their shares of the respective
predecessor entity. In connection with the reorganization, Janus Flexible Income
Fund changed its fiscal year end from December 31 to October 31. All references
in this SAI to Janus Flexible Income Fund and Janus Twenty Fund, and all
financial and other information about such Funds prior to August 7, 1992, are to
the respective predecessor entities; all references after August 7, 1992, are to
the respective series of the Trust.
 
     Janus Capital reserves the right to the name "Janus." In the event that
Janus Capital does not continue to provide investment advice to the Funds, the
Funds must cease to use the name "Janus" as soon as reasonably practicable.
 
     Under Massachusetts law, shareholders of the Funds could, under certain
circumstances, be held liable for the obligations of their Fund. However, the
Declaration of Trust disclaims shareholder liability for acts or obligations of
the Funds and requires that notice of this disclaimer be given in each
agreement, obligation or instrument entered into or executed by the Funds or the
Trustees. The Declaration of Trust also provides for indemnification from the
assets of the Funds for all losses and expenses of any Fund shareholder held
liable for the obligations of their Fund. Thus, the risk of a shareholder
incurring a financial loss on account of its liability as a shareholder of one
of the Funds is limited to circumstances in which their Fund would be unable to
meet its obligations. The possibility that these circumstances would occur is
remote. The Trustees intend to conduct the operations of the Funds to avoid, to
the extent possible, liability of shareholders for liabilities of their Fund.
 
SHARES OF THE TRUST
     The Trust is authorized to issue an unlimited number of shares of
beneficial interest with a par value of one cent per share for each series of
the Trust. Shares of each Fund are fully paid and nonassessable when issued. All
shares of a Fund participate equally in dividends and other distributions by
such Fund, and in residual assets of that Fund in the event of liquidation.
Shares of each Fund have no preemptive, conversion or subscription rights.
Shares of each Fund may be transferred by endorsement or stock power as is
customary, but a Fund is not bound to recognize any transfer until it is
recorded on its books.
 
                                       43
<PAGE>   
 
VOTING RIGHTS
     The present Trustees were elected at a meeting of shareholders held on July
10, 1992, with the exception of Mr. Craig and Mr. Rothe who were appointed by
the Trustees as of June 30, 1995 and January 1, 1997, respectively. Under the
Declaration of Trust, each Trustee will continue in office until the termination
of the Trust or his earlier death, retirement, resignation, bankruptcy,
incapacity or removal. Vacancies will be filled by a majority of the remaining
Trustees, subject to the 1940 Act. Therefore, no annual or regular meetings of
shareholders normally will be held, unless otherwise required by the Declaration
of Trust or the 1940 Act. Subject to the foregoing, shareholders have the power
to vote to elect or remove Trustees, to terminate or reorganize their Fund, to
amend the Declaration of Trust, to bring certain derivative actions and on any
other matters on which a shareholder vote is required by the 1940 Act, the
Declaration of Trust, the Trust's Bylaws or the Trustees.
 
   
     Each share of each series of the Trust has one vote (and fractional votes
for fractional shares). Shares of all series of the Trust have noncumulative
voting rights, which means that the holders of more than 50% of the shares of
all series of the Trust voting for the election of Trustees can elect 100% of
the Trustees if they choose to do so and, in such event, the holders of the
remaining shares will not be able to elect any Trustees. Each series of the
Trust will vote separately only with respect to those matters that affect only
that series or if a series' interest in the matter differs from the interests of
other series of the Trust.
    
 
INDEPENDENT ACCOUNTANTS
     Price Waterhouse LLP, 950 Seventeenth Street, Suite 2500, Denver, Colorado
80202, independent accountants for the Funds, audit the Funds' annual financial
statements and prepare their tax returns.
 
REGISTRATION STATEMENT
     The Trust has filed with the SEC, Washington, D.C., a Registration
Statement under the Securities Act of 1933, as amended, with respect to the
securities to which this SAI relates. If further information is desired with
respect to the Funds or such securities, reference is made to the Registration
Statement and the exhibits filed as a part thereof.
 
                            PERFORMANCE INFORMATION
 
     The Prospectus contains a brief description of how performance is
calculated.
 
     Quotations of average annual total return for a Fund will be expressed in
terms of the average annual compounded rate of return of a hypothetical
investment in such Fund over periods of 1, 5, and 10 years (up to the life of
the Fund). These are the annual total rates of return that would equate the
initial amount invested to the ending redeemable value. These rates of return
are calculated pursuant to the following formula: P(1 + T)n = ERV (where P = a
hypothetical initial payment of $1,000, T = the average annual total return, n =
the number of years and ERV = the ending redeemable value of a hypothetical
$1,000 payment made at the beginning of the
 
                                       44
<PAGE>   
 
period). All total return figures reflect the deduction of a proportional share
of Fund expenses on an annual basis, and assume that all dividends and
distributions are reinvested when paid.
 
   
     The average annual total return of each Fund, computed as of October 31,
1997, is shown in the table below:
    
 
   
     [To be filed by Amendment]
    
 
   
<TABLE>
<CAPTION>
                                                            Average Annual Total Return
                                 Date        Number      ----------------------------------
                               Available    of Months     One      Five     Ten     Life of
          Fund Name            for Sale    in Lifetime    Year    Years    Years     Fund
- -------------------------------------------------------------------------------------------
<S>                            <C>         <C>           <C>      <C>      <C>      <C>
Janus Fund                        2/5/70       333            %        %        %        %
Janus Enterprise Fund             9/1/92        62            %        %      N/A        %
Janus Mercury Fund                5/3/93        54            %      N/A      N/A        %
Janus Olympus Fund              12/29/95        22            %      N/A      N/A        %
Janus Overseas Fund               5/2/94        42            %      N/A      N/A        %
Janus Special Situations Fund   12/31/96        10          N/A      N/A      N/A        %
Janus Twenty Fund                 5/2/85       150            %        %        %        %
Janus Worldwide Fund             5/15/91      77.5            %        %      N/A        %
Janus Balanced Fund               9/1/92        62            %        %      N/A        %
Janus Equity Income Fund         6/28/96        16            %      N/A      N/A        %
Janus Growth and Income Fund     5/15/91      77.5            %        %      N/A        %
Janus Flexible Income Fund        7/2/87       124            %        %        %        %
Janus High-Yield Fund           12/29/95        22            %      N/A      N/A        %
Janus Federal Tax-Exempt Fund     5/3/93        54            %      N/A      N/A        %
Janus Short-Term Bond Fund        9/1/92        62            %        %      N/A        %
- -------------------------------------------------------------------------------------------
</TABLE>
    
 
     Quotations of a Fund's yield are based on the investment income per share
earned during a particular 30-day period (including dividends, if any, and
interest), less expenses accrued during the period ("net investment income"),
and are computed by dividing net investment income by the net asset value per
share on the last day of the period, according to the following formula:
 
                         YIELD = 2[(a - b + 1)(6) - 1]
           ----------------------------------------------
            cd
 
     where a = dividend and interest income
   
           b = expenses accrued for the period (net of reimbursements)
    
           c = average daily number of shares outstanding during the period that
               were
               entitled to receive dividends
           d = maximum net asset value per share on the last day of the period
 
     The tax-equivalent yield used for Janus Federal Tax-Exempt Fund is the rate
that an investor would have to earn from a fully taxable investment after taxes
to equal the Fund's tax-free yield. Tax-equivalent yields are calculated by
dividing a Fund's yield by the result of one minus a stated federal or combined
federal and state tax rate. If only a portion of a Funds' yield is tax-exempt,
only that portion is adjusted in the calculation. Janus Federal Tax-Exempt Fund
may invest a portion of its assets in obligations that are subject to federal
income tax. When the Fund invests in these obligations, its tax-equivalent yield
will be lower.
 
                                       45
<PAGE>   
 
   
     The yield for the 30-day period ending October 31, 1997, for the
Fixed-Income Funds is shown below:
    
 
   
     [To be filed by Amendment]
    
 
   
<TABLE>
<S>                                             <C>
Janus Flexible Income Fund                           %
Janus High-Yield Fund                                %
Janus Federal Tax-Exempt Fund                        %
Janus Short-Term Bond Fund                           %
</TABLE>
    
 
   
     From time to time in advertisements or sales material, the Funds may
discuss their performance ratings or other information as published by
recognized mutual fund statistical rating services, including, but not limited
to, Lipper Analytical Services, Inc., Ibbotson Associates, Micropal or
Morningstar, Inc. or by publications of general interest such as Forbes, Money,
The Wall Street Journal, Mutual Funds Magazine, Kiplinger's, or Smart Money. The
Funds may also compare their performance to that of other selected mutual funds,
mutual fund averages or recognized stock market indicators, including, but not
limited to, the Standard & Poor's 500 Composite Stock Price Index, the Standard
& Poor's 400 Midcap Index, the Dow Jones Industrial Average, the Lehman Brothers
Government/Corporate Bond Index, the Lehman Brothers Government/ Corporate 1-3
Year Bond Index, the Lehman Brothers Long Government/Corporate Bond Index, the
Lehman Brothers Intermediate Government Bond Index, the Lehman Brothers
Municipal Bond Index, the Russell 2000 Index and the NASDAQ composite. In
addition, the Funds may compare their total return or yield to the yield on U.S.
Treasury obligations and to the percentage change in the Consumer Price Index.
Janus Worldwide Fund and Janus Overseas Fund may also compare their performance
to the record of global market indicators, such as the Morgan Stanley
International World Index or Morgan Stanley Capital International Europe,
Australasia, Far East Index (EAFE Index). Such performance ratings or
comparisons may be made with funds that may have different investment
restrictions, objectives, policies or techniques than the Funds and such other
funds or market indicators may be comprised of securities that differ
significantly from the Funds' investments.
    
 
                                       46
<PAGE>   
 
                              FINANCIAL STATEMENTS
 
     [To be filed by Amendment]
 
   
     The following audited financial statements for the period ended October 31,
1997 are hereby incorporated into this SAI by reference to the Funds' Annual
Reports dated October 31, 1997. Copies of such reports accompany this SAI.
    
 
DOCUMENTS INCORPORATED BY REFERENCE TO THE ANNUAL REPORTS:
 
   
     Schedules of Investments as of October 31, 1997
    
 
   
     Statements of Operations for the period ended October 31, 1997
    
 
   
     Statements of Assets and Liabilities as of October 31, 1997
    
 
   
    Statements of Changes in Net Assets for the periods ended October 31, 1997
    
   
    and 1996
    
 
     Financial Highlights for each of the periods indicated
 
     Notes to Financial Statements
 
     Report of Independent Accountants
 
     The portions of such Annual Reports that are not specifically listed above
are not incorporated by reference into this SAI and are not part of the
Registration Statement.
 
                                       47
<PAGE>   
 
                                   APPENDIX A
 
EXPLANATION OF RATING CATEGORIES
 
   
     The following is a description of credit ratings issued by two of the major
credit ratings agencies. Credit ratings evaluate only the safety of principal
and interest payments, not the market value risk of lower quality securities.
Credit rating agencies may fail to change credit ratings to reflect subsequent
events on a timely basis. Although Janus Capital considers security ratings when
making investment decisions, it also performs its own investment analysis and
does not rely solely on the ratings assigned by credit agencies.
    
 
STANDARD & POOR'S RATINGS SERVICES
 
<TABLE>
<S>                  <C>
BOND RATING          EXPLANATION
- ------------------------------------------------------------------------
INVESTMENT GRADE
AAA                  Highest rating; extremely strong capacity to pay
                     principal and interest.
AA                   High quality; very strong capacity to pay principal
                     and interest.
A                    Strong capacity to pay principal and interest;
                     somewhat more susceptible to the adverse effects of
                     changing circumstances and economic conditions.
BBB                  Adequate capacity to pay principal and interest;
                     normally exhibit adequate protection parameters,
                     but adverse economic conditions or changing
                     circumstances more likely to lead to a weakened
                     capacity to pay principal and interest than for
                     higher rated bonds.
NON-INVESTMENT GRADE
BB, B,               Predominantly speculative with respect to the
CCC, CC, C           issuer's capacity to meet required interest and
                     principal payments. BB -- lowest degree of
                     speculation; C -- the highest degree of
                     speculation. Quality and protective characteristics
                     outweighed by large uncertainties or major risk
                     exposure to adverse conditions.
D                    In default.
- ------------------------------------------------------------------------
</TABLE>
 
                                       48
<PAGE>   
 
MOODY'S INVESTORS SERVICE, INC.
 
<TABLE>
<S>                  <C>
BOND RATING          EXPLANATION
- ------------------------------------------------------------------------
INVESTMENT GRADE
Aaa                  Highest quality, smallest degree of investment
                     risk.
Aa                   High quality; together with Aaa bonds, they compose
                     the high-grade bond group.
A                    Upper-medium grade obligations; many favorable
                     investment attributes.
Baa                  Medium-grade obligations; neither highly protected
                     nor poorly secured. Interest and principal appear
                     adequate for the present but certain protective
                     elements may be lacking or may be unreliable over
                     any great length of time.
NON-INVESTMENT GRADE
Ba                   More uncertain, with speculative elements.
                     Protection of interest and principal payments not
                     well safeguarded during good and bad times.
B                    Lack characteristics of desirable investment;
                     potentially low assurance of timely interest and
                     principal payments or maintenance of other contract
                     terms over time.
Caa                  Poor standing, may be in default; elements of
                     danger with respect to principal or interest
                     payments.
Ca                   Speculative in a high degree; could be in default
                     or have other marked shortcomings.
C                    Lowest-rated; extremely poor prospects of ever
                     attaining investment standing.
- ------------------------------------------------------------------------
</TABLE>
 
   
     Unrated securities will be treated as noninvestment grade securities unless
a portfolio manager determines that such securities are the equivalent of
investment grade securities. Securities that have received different ratings
from more than one agency are considered investment grade if at least one agency
has rated the security investment grade.
    
 
                                       49
<PAGE>   
 
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<PAGE>   
 
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<PAGE>   
 
                             JANUS INVESTMENT FUND
 
                              100 Fillmore Street
                             Denver, CO 80206-4928
                                 (800) 525-3713
 
                      STATEMENT OF ADDITIONAL INFORMATION
   
                               FEBRUARY 17, 1998
    
 
                            JANUS MONEY MARKET FUND
                       JANUS GOVERNMENT MONEY MARKET FUND
                       JANUS TAX-EXEMPT MONEY MARKET FUND
                                Investor Shares
 
     This Statement of Additional Information ("SAI") expands upon and
supplements the information contained in the current Prospectus for the Investor
Shares (the "Shares") of Janus Money Market Fund, Janus Government Money Market
Fund and Janus Tax-Exempt Money Market Fund (individually, a "Fund" and,
collectively, the "Funds"). The Funds are each a separate series of Janus
Investment Fund, a Massachusetts business trust (the "Trust"). Each Fund
represents shares of beneficial interest in a separate portfolio of securities
and other assets with its own objective and policies, and is managed separately
by Janus Capital Corporation ("Janus Capital").
 
   
     This SAI is not a Prospectus and should be read in conjunction with the
Prospectus dated February 17, 1998, which is incorporated by reference into this
SAI and may be obtained from the Trust at the above phone number or address.
This SAI contains additional and more detailed information about the Funds'
operations and activities than the Prospectus.
    
 
                                      LOGO
<PAGE>   
 
                             JANUS INVESTMENT FUND
                      STATEMENT OF ADDITIONAL INFORMATION
                               TABLE OF CONTENTS
 
Investment Policies and Restrictions.......................................... 3
   
Types of Securities and Investment Techniques................................. 5
    
   
Performance Data............................................................. 10
    
   
Determination of Net Asset Value............................................. 11
    
   
Investment Adviser and Administrator......................................... 12
    
   
Custodian, Transfer Agent and Certain Affiliations........................... 15
    
   
Portfolio Transactions and Brokerage......................................... 15
    
   
Officers and Trustees........................................................ 17
    
   
Purchase of Shares........................................................... 20
    
   
Redemption of Shares......................................................... 20
    
   
Shareholder Accounts......................................................... 21
    
   
Tax-Deferred Accounts........................................................ 21
    
   
Dividends and Tax Status..................................................... 22
    
   
Principal Shareholders....................................................... 23
    
   
Miscellaneous Information.................................................... 23
    
   
     Shares of the Trust..................................................... 24
    
   
     Voting Rights........................................................... 24
    
   
     Independent Accountants................................................. 25
    
   
     Registration Statement.................................................. 25
    
   
Financial Statements......................................................... 25
    
   
Appendix A - Description of Securities Ratings............................... 26
    
   
Appendix B - Description of Municipal Securities............................. 29
    
- --------------------------------------------------------------------------------
 
                                        2
<PAGE>   
 
                              INVESTMENT POLICIES
                                AND RESTRICTIONS
 
INVESTMENT OBJECTIVES
     As discussed in the Prospectus, the investment objective of each of Janus
Money Market Fund and Janus Government Money Market Fund is to seek maximum
current income to the extent consistent with stability of capital. The
investment objective of Janus Tax-Exempt Money Market Fund is to seek maximum
current income that is exempt from federal income taxes to the extent consistent
with stability of capital. There can be no assurance that a Fund will achieve
its investment objective or maintain a stable net asset value of $1.00 per
share. The investment objectives of the Funds are not fundamental and may be
changed by the Trustees of the Trust (the "Trustees") without shareholder
approval.
 
INVESTMENT RESTRICTIONS APPLICABLE TO ALL FUNDS
     As indicated in the Prospectus, each Fund has adopted certain fundamental
investment restrictions that cannot be changed without shareholder approval.
Shareholder approval means approval by the lesser of (i) more than 50% of the
outstanding voting securities of the Trust (or a particular Fund or particular
class of Shares if a matter affects just that Fund or that class of Shares), or
(ii) 67% or more of the voting securities present at a meeting if the holders of
more than 50% of the outstanding voting securities of the Trust (or a particular
Fund or class of Shares) are present or represented by proxy.
 
     As used in the restrictions set forth below and as used elsewhere in this
SAI, the term "U.S. Government Securities" shall have the meaning set forth in
the Investment Company Act of 1940, as amended (the "1940 Act"). The 1940 Act
defines U.S. Government Securities as securities issued or guaranteed by the
United States government, its agencies or instrumentalities. U.S. Government
Securities may also include repurchase agreements collateralized and municipal
securities escrowed with or refunded with escrowed U.S. government securities.
 
     The Funds have adopted the following fundamental policies:
 
     (1) With respect to 75% of its assets, a Fund may not purchase a security
other than a U.S. Government Security, if, as a result, more than 5% of the
Fund's total assets would be invested in the securities of a single issuer or
the Fund would own more than 10% of the outstanding voting securities of any
single issuer. (As noted in the Prospectus, the Funds are also currently subject
to the greater diversification standards of Rule 2a-7, which are not
fundamental.)
 
     (2) A Fund may not purchase securities if 25% or more of the value of a
Fund's total assets would be invested in the securities of issuers conducting
their principal business activities in the same industry; provided that: (i)
there is no limit on investments in U.S. Government Securities or in obligations
of domestic commercial banks (including U.S. branches of foreign banks subject
to regulations under U.S. laws applicable to domestic banks and, to the extent
that its parent is unconditionally liable for the obligation, foreign branches
of U.S. banks); (ii) this limitation shall not apply to
 
                                        3
<PAGE>   
 
a Fund's investments in municipal securities; (iii) there is no limit on
investments in issuers domiciled in a single country; (iv) financial service
companies are classified according to the end users of their services (for
example, automobile finance, bank finance and diversified finance are each
considered to be a separate industry); and (v) utility companies are classified
according to their services (for example, gas, gas transmission, electric, and
telephone are each considered to be a separate industry).
 
     (3) A Fund may not act as an underwriter of securities issued by others,
except to the extent that a Fund may be deemed an underwriter in connection with
the disposition of portfolio securities of such Fund.
 
     (4) A Fund may not lend any security or make any other loan if, as a
result, more than 25% of a Fund's total assets would be lent to other parties
(but this limitation does not apply to purchases of commercial paper, debt
securities or repurchase agreements).
 
     (5) A Fund may not purchase or sell real estate or any interest therein,
except that the Fund may invest in debt obligations secured by real estate or
interests therein or securities issued by companies that invest in real estate
or interests therein.
 
     (6) A Fund may borrow money for temporary or emergency purposes (not for
leveraging) in an amount not exceeding 25% of the value of its total assets
(including the amount borrowed) less liabilities (other than borrowings). If
borrowings exceed 25% of the value of a Fund's total assets by reason of a
decline in net assets, the Fund will reduce its borrowings within three business
days to the extent necessary to comply with the 25% limitation. Reverse
repurchase agreements or the segregation of assets in connection with such
agreements shall not be considered borrowing for the purposes of this limit.
 
     (7) Each Fund may, notwithstanding any other investment policy or
restriction (whether or not fundamental), invest all of its assets in the
securities of a single open-end management investment company with substantially
the same fundamental investment objectives, policies and restrictions as that
Fund.
 
     Each Fund has adopted the following nonfundamental investment restrictions
that may be changed by the Trustees without shareholder approval:
 
     (1) A Fund may not invest in securities or enter into repurchase agreements
with respect to any securities if, as a result, more than 10% of the Fund's net
assets would be invested in repurchase agreements not entitling the holder to
payment of principal within seven days and in other securities that are not
readily marketable ("illiquid securities"). The Trustees, or the Fund's
investment adviser acting pursuant to authority delegated by the Trustees, may
determine that a readily available market exists for certain securities such as
securities eligible for resale pursuant to Rule 144A under the Securities Act of
1933, or any successor to such rule, Section 4(2) commercial paper and municipal
lease obligations. Accordingly, such securities may not be subject to the
foregoing limitation.
 
     (2) A Fund may not purchase securities on margin, or make short sales of
securities, except for short sales against the box and the use of short-term
credit necessary for the clearance of purchases and sales of portfolio
securities.
 
                                        4
<PAGE>   
 
     (3) A Fund may not pledge, mortgage, hypothecate or encumber any of its
assets except to secure permitted borrowings or in connection with permitted
short sales.
 
     (4) A Fund may not invest in companies for the purpose of exercising
control of management.
 
   
     Under the terms of an exemptive order received from the Securities and
Exchange Commission ("SEC"), each of the Funds may borrow money from or lend
money to other funds that permit such transactions and for which Janus Capital
serves as investment adviser. All such borrowing and lending will be subject to
the above limits.  A Fund will borrow money through the program only when the
costs are equal to or lower than the cost of bank loans.  Interfund loans and
borrowings normally extend overnight, but can have a maximum duration of seven
days.  A Fund will lend through the program only when the returns are higher
than those available from other short-term instruments (such as repurchase
agreements).  A Fund may have to borrow from a bank at a higher interest rate 
if an interfund loan is called or not renewed.  Any delay in repayment to a 
lending Fund could result in a lost investment opportunity or additional 
borrowing costs.    
    
 
   
     For purposes of the Funds' restriction on investing in a particular
industry, the Funds will rely primarily on industry classifications as published
by Bloomberg L.P. To the extent that such classifications are so broad that the
primary economic characteristics in a single class are materially different, the
Funds may further classify issuers in accordance with industry classifications
as published by the SEC.
    
 
                            TYPES OF SECURITIES AND
                             INVESTMENT TECHNIQUES
 
     Each of the Funds may invest only in "eligible securities" as defined in
Rule 2a-7 adopted under the 1940 Act. Generally, an eligible security is a
security that (i) is denominated in U.S. dollars and has a remaining maturity of
397 days or less (as calculated pursuant to Rule 2a-7); (ii) is rated, or is
issued by an issuer with short-term debt outstanding that is rated, in one of
the two highest rating categories by any two nationally recognized statistical
rating organizations ("NRSROs") or, if only one NRSRO has issued a rating, by
that NRSRO (the "Requisite NRSROs") or is unrated and of comparable quality to a
rated security, as determined by Janus Capital; and (iii) has been determined by
Janus Capital to present minimal credit risks pursuant to procedures approved by
the Trustees. In addition, the Funds will maintain a dollar-weighted average
portfolio maturity of 90 days or less. A description of the ratings of some
NRSROs appears in Appendix A.
 
     Under Rule 2a-7, a Fund may not invest more than five percent of its total
assets in the securities of any one issuer other than U.S. Government
Securities, provided that in certain cases a Fund may invest more than 5% of its
assets in a single issuer for a period of up to three business days. Until
pending amendments to Rule 2a-7 become effective, up to 25% of Janus Tax-Exempt
Money Market Fund's assets may be invested without regard to the foregoing
limitations.
 
     Pursuant to Rule 2a-7, each Fund (except Janus Tax-Exempt Money Market
Fund) will invest at least 95% of its total assets in "first-tier" securities.
First-tier securities are eligible securities that are rated, or are issued by
an issuer with short-term debt outstanding that is rated, in the highest rating
category by the Requisite NRSROs or are unrated and of comparable quality to a
rated security. In addition, a Fund may invest in "second-tier" securities which
are eligible securities that are not first-tier securities. However, a Fund
(except for Janus Tax-Exempt Money Market Fund, in certain cases) may not invest
in a second-tier security if immediately after the acquisition thereof the
 
                                        5
<PAGE>   
 
Fund would have invested more than (i) the greater of one percent of its total
assets or one million dollars in second-tier securities issued by that issuer,
or (ii) five percent of its total assets in second-tier securities.
 
     The following discussion of types of securities in which the Funds may
invest supplements and should be read in conjunction with the Prospectus.
 
PARTICIPATION INTERESTS
     Each Fund may purchase participation interests in loans or securities in
which the Funds may invest directly. Participation interests are generally
sponsored or issued by banks or other financial institutions. A participation
interest gives a Fund an undivided interest in the underlying loans or
securities in the proportion that the Fund's interest bears to the total
principal amount of the underlying loans or securities. Participation interests,
which may have fixed, floating or variable rates, may carry a demand feature
backed by a letter of credit or guarantee of a bank or institution permitting
the holder to tender them back to the bank or other institution. For certain
participation interests, a Fund will have the right to demand payment, on not
more than seven days' notice, for all or a part of the Fund's participation
interest. The Funds intend to exercise any demand rights they may have upon
default under the terms of the loan or security, to provide liquidity or to
maintain or improve the quality of the Funds' investment portfolio. A Fund will
only purchase participation interests that Janus Capital determines present
minimal credit risks.
 
VARIABLE AND FLOATING RATE NOTES
     Janus Money Market Fund also may purchase variable and floating rate demand
notes of corporations and other entities, which are unsecured obligations
redeemable upon not more than 30 days' notice. These obligations include master
demand notes that permit investment of fluctuating amounts at varying rates of
interest pursuant to direct arrangements with the issuer of the instrument. The
issuer of these obligations often has the right, after a given period, to prepay
the outstanding principal amount of the obligations upon a specified number of
days' notice. These obligations generally are not traded, nor generally is there
an established secondary market for these obligations. To the extent a demand
note does not have a seven day or shorter demand feature and there is no readily
available market for the obligation, it is treated as an illiquid investment.
 
MORTGAGE- AND ASSET-BACKED SECURITIES
     The Funds may invest in mortgage-backed securities, which represent an
interest in a pool of mortgages made by lenders such as commercial banks,
savings and loan institutions, mortgage bankers, mortgage brokers and savings
banks. Mortgage-backed securities may be issued by governmental or
government-related entities or by non-governmental entities such as banks,
savings and loan institutions, private mortgage insurance companies, mortgage
bankers and other secondary market issuers.
 
     Interests in pools of mortgage-backed securities differ from other forms of
debt securities which normally provide for periodic payment of interest in fixed
amounts with principal payments at maturity or specified call dates. In
contrast, mortgage-backed securities provide periodic payments which consist of
interest and, in most cases,
 
                                        6
<PAGE>   
 
principal. In effect, these payments are a "pass-through" of the periodic
payments and optional prepayments made by the individual borrowers on their
mortgage loans, net of any fees paid to the issuer or guarantor of such
securities. Additional payments to holders of mortgage-backed securities are
caused by prepayments resulting from the sale of the underlying residential
property, refinancing or foreclosure, net of fees or costs which may be
incurred.
 
     As prepayment rates of individual pools of mortgage loans vary widely, it
is not possible to predict accurately the average life of a particular security.
Although mortgage-backed securities are issued with stated maturities of up to
forty years, unscheduled or early payments of principal and interest on the
underlying mortgages may shorten considerably the effective maturities.
Mortgage-backed securities may have varying assumptions for average life. The
volume of prepayments of principal on a pool of mortgages underlying a
particular security will influence the yield of that security, and the principal
returned to a Fund may be reinvested in instruments whose yield may be higher or
lower than that which might have been obtained had the prepayments not occurred.
When interest rates are declining, prepayments usually increase, with the result
that reinvestment of principal prepayments will be at a lower rate than the rate
applicable to the original mortgage-backed security.
 
     The Funds may invest in mortgage-backed securities that are issued by
agencies or instrumentalities of the U.S. government. The Government National
Mortgage Association ("GNMA") is the principal federal government guarantor of
mortgage-backed securities. GNMA is a wholly-owned U.S. government corporation
within the Department of Housing and Urban Development. GNMA Certificates are
debt securities which represent an interest in one mortgage or a pool of
mortgages which are insured by the Federal Housing Administration or the Farmers
Home Administration or are guaranteed by the Veterans Administration. The Funds
may also invest in pools of conventional mortgages which are issued or
guaranteed by agencies of the U.S. government. GNMA pass-through securities are
considered to be riskless with respect to default in that (i) the underlying
mortgage loan portfolio is comprised entirely of government-backed loans and
(ii) the timely payment of both principal and interest on the securities is
guaranteed by the full faith and credit of the U.S. government, regardless of
whether or not payments have been made on the underlying mortgages. GNMA
pass-through securities are, however, subject to the same market risk as
comparable debt securities. Therefore, the market value of a Fund's GNMA
securities can be expected to fluctuate in response to changes in prevailing
interest rate levels.
 
     Residential mortgage loans are pooled also by the Federal Home Loan
Mortgage Corporation ("FHLMC"). FHLMC is a privately managed, publicly chartered
agency created by Congress in 1970 for the purpose of increasing the
availability of mortgage credit for residential housing. FHLMC issues
participation certificates ("PCs") which represent interests in mortgages from
FHLMC's national portfolio. The mortgage loans in FHLMC's portfolio are not U.S.
government backed; rather, the loans are either uninsured with loan-to-value
ratios of 80% or less, or privately insured if the loan-to-value ratio exceeds
80%. FHLMC guarantees the timely payment of interest and ultimate collection of
principal on FHLMC PCs; the U.S. government does not guarantee any aspect of
FHLMC PCs.
 
                                        7
<PAGE>   
 
     The Federal National Mortgage Association ("FNMA") is a
government-sponsored corporation owned entirely by private shareholders. It is
subject to general regulation by the Secretary of Housing and Urban Development.
FNMA purchases residential mortgages from a list of approved seller/servicers
which include savings and loan associations, savings banks, commercial banks,
credit unions and mortgage bankers. FNMA guarantees the timely payment of
principal and interest on the pass-through securities issued by FNMA; the U.S.
government does not guarantee any aspect of the FNMA pass-through securities.
 
     The Funds may also invest in privately-issued mortgage-backed securities to
the extent permitted by their investment restrictions. Mortgage-backed
securities offered by private issuers include pass-through securities comprised
of pools of conventional residential mortgage loans; mortgage-backed bonds which
are considered to be debt obligations of the institution issuing the bonds and
which are collateralized by mortgage loans; and collateralized mortgage
obligations ("CMOs") which are collateralized by mortgage-backed securities
issued by GNMA, FHLMC or FNMA or by pools of conventional mortgages.
 
     Asset-backed securities represent direct or indirect participations in, or
are secured by and payable from, assets other than mortgage-backed assets such
as motor vehicle installment sales contracts, installment loan contracts, leases
of various types of real and personal property and receivables from revolving
credit agreements (credit cards). Asset-backed securities have yield
characteristics similar to those of mortgage-backed securities and, accordingly,
are subject to many of the same risks.
 
REVERSE REPURCHASE AGREEMENTS
     Reverse repurchase agreements are transactions in which a Fund sells a
security and simultaneously commits to repurchase that security from the buyer
at an agreed upon price on an agreed upon future date. The resale price in a
reverse repurchase agreement reflects a market rate of interest that is not
related to the coupon rate or maturity of the sold security. For certain demand
agreements, there is no agreed upon repurchase date and interest payments are
calculated daily, often based upon the prevailing overnight repurchase rate. The
Funds will use the proceeds of reverse repurchase agreements only to satisfy
unusually heavy redemption requests or for other temporary or emergency purposes
without the necessity of selling portfolio securities.
 
     Generally, a reverse repurchase agreement enables the Fund to recover for
the term of the reverse repurchase agreement all or most of the cash invested in
the portfolio securities sold and to keep the interest income associated with
those portfolio securities. Such transactions are only advantageous if the
interest cost to the Fund of the reverse repurchase transaction is less than the
cost of obtaining the cash otherwise. In addition, interest costs on the money
received in a reverse repurchase agreement may exceed the return received on the
investments made by a Fund with those monies.
 
WHEN-ISSUED AND DELAYED DELIVERY SECURITIES
     Each Fund may purchase securities on a when-issued or delayed delivery
basis. A Fund will enter into such transactions only when it has the intention
of actually acquiring the securities. To facilitate such acquisitions, the
Funds' custodian will segregate cash or high quality liquid assets in an amount
at least equal to such
 
                                        8
<PAGE>   
 
commitments. On delivery dates for such transactions, the Fund will meet its
obligations from maturities, sales of the segregated securities or from other
available sources of cash. If a Fund chooses to dispose of the right to acquire
a when-issued security prior to its acquisition, it could, as with the
disposition of any other portfolio obligation, incur a gain or loss due to
market fluctuation. At the time a Fund makes the commitment to purchase
securities on a when-issued or delayed delivery basis, it will record the
transaction as a purchase and thereafter reflect the value of such securities in
determining its net asset value.
 
INVESTMENT COMPANY SECURITIES
   
     From time to time, the Funds may invest in securities of other investment
companies. The Funds are subject to the provisions of Section 12(d)(1) of the
1940 Act. The Janus funds are seeking an amended and restated exemptive order
that would permit the non-money market funds to invest in the Janus money market
funds in excess of the limitations of Section 12(d)(1) of the 1940 Act. There is
no assurance that such amendment will be granted.
    
 
MUNICIPAL LEASES
     Janus Money Market Fund and Janus Tax-Exempt Money Market Fund may invest
in municipal leases. Municipal leases frequently have special risks not normally
associated with general obligation or revenue bonds. Leases and installment
purchase or conditional sales contracts (which normally provide for title to the
leased asset to pass eventually to the government issuer) have evolved as a
means for governmental issuers to acquire property and equipment without meeting
the constitutional and statutory requirements for the issuance of debt. The
debt-issuance limitations of many state constitutions and statutes are deemed to
be inapplicable because of the inclusion in many leases or contracts of
"non-appropriation" clauses that provide that the governmental issuer has no
obligation to make future payments under the lease or contract unless money is
appropriated for such purpose by the appropriate legislative body on a yearly or
other periodic basis. The Fund will only purchase municipal leases subject to a
non-appropriation clause when the payment of principal and accrued interest is
backed by an unconditional, irrevocable letter of credit, or guarantee of a bank
or other entity that meets the criteria described in the Prospectus under
"Taxable Investments".
 
     In evaluating municipal lease obligations, Janus Capital will consider such
factors as it deems appropriate, including: (a) whether the lease can be
canceled; (b) the ability of the lease obligee to direct the sale of the
underlying assets; (c) the general creditworthiness of the lease obligor; (d)
the likelihood that the municipality will discontinue appropriating funding for
the leased property in the event such property is no longer considered essential
by the municipality; (e) the legal recourse of the lease obligee in the event of
such a failure to appropriate funding; (f) whether the security is backed by a
credit enhancement such as insurance; and (g) any limitations which are imposed
on the lease obligor's ability to utilize substitute property or services other
than those covered by the lease obligation. If a lease is backed by an
unconditional letter of credit or other unconditional credit enhancement, then
Janus Capital may determine that a lease is an eligible security solely on the
basis of its evaluation of the credit enhancement.
 
                                        9
<PAGE>   
 
     Municipal leases, like other municipal debt obligations, are subject to the
risk of non-payment. The ability of issuers of municipal leases to make timely
lease payments may be adversely impacted in general economic downturns and as
relative governmental cost burdens are allocated and reallocated among federal,
state and local governmental units. Such non-payment would result in a reduction
of income to the Fund, and could result in a reduction in the value of the
municipal lease experiencing non-payment and a potential decrease in the net
asset value of the Fund.
 
                                PERFORMANCE DATA
 
     A Fund may provide current annualized and effective annualized yield
quotations based on its daily dividends. These quotations may from time to time
be used in advertisements, shareholder reports or other communications to
shareholders. All performance information supplied by the Funds in advertising
is historical and is not intended to indicate future returns.
 
     In performance advertising, the Funds may compare their Shares' performance
information with data published by independent evaluators such as Morningstar,
Inc., Lipper Analytical Services, Inc., CDC/Wiesenberger, IBC/Donoghue's Money
Fund Report or other companies which track the investment performance of
investment companies ("Fund Tracking Companies"). The Funds may also compare
their Shares' performance information with the performance of recognized stock,
bond and other indices, including but not limited to the Municipal Bond Buyers
Indices, the Salomon Brothers Bond Index, the Lehman Bond Index, the Standard &
Poor's 500 Composite Stock Price Index, the Dow Jones Industrial Average, U.S.
Treasury bonds, bills or notes and changes in the Consumer Price Index as
published by the U.S. Department of Commerce. The Funds may refer to general
market performance over past time periods such as those published by Ibbotson
Associates (for instance, its "Stocks, Bonds, Bills and Inflation Yearbook").
The Funds may also refer in such materials to mutual fund performance rankings
and other data published by Fund Tracking Companies. Performance advertising may
also refer to discussions of the Funds and comparative mutual fund data and
ratings reported in independent periodicals, such as newspapers and financial
magazines. The Funds may also compare the Shares' yield to those of certain U.S.
Treasury obligations or other money market instruments.
 
     Any current yield quotation of the Shares which is used in such a manner as
to be subject to the provisions of Rule 482(d) under the Securities Act of 1933,
as amended, shall consist of an annualized historical yield, carried at least to
the nearest hundredth of one percent, based on a specific seven calendar day
period. The Fund's current yield shall be calculated by (a) determining the net
change during a seven calendar day period in the value of a hypothetical account
having a balance of one share at the beginning of the period, (b) dividing the
net change by the value of the account at the beginning of the period to obtain
a base period return, and (c) multiplying the quotient by 365/7 (i.e.,
annualizing). For this purpose, the net change in account value would reflect
the value of additional Shares purchased with dividends declared on the original
Share and dividends declared on both the original Share and any such additional
Shares, but would not reflect any realized gains or losses from the sale of
securities or any unrealized appreciation or depreciation on portfolio
securities. In addition, the Shares may advertise
 
                                       10
<PAGE>   
 
effective yield quotations. Effective yield quotations are calculated by adding
1 to the base period return, raising the sum to a power equal to 365/7, and
subtracting 1 from the result (i.e., compounding).
 
     Janus Tax-Exempt Money Market Fund's tax equivalent yield is the rate an
investor would have to earn from a fully taxable investment in order to equal
such Shares' yield after taxes. Tax equivalent yields are calculated by dividing
Janus Tax-Exempt Money Market Fund's yield by one minus the stated federal or
combined federal and state tax rate. If only a portion of the Shares' yield is
tax-exempt, only that portion is adjusted in the calculation.
 
   
     The Shares' current yield and effective yield for the seven-day period
ended October 31, 1997 is shown below:
    
   
[TO BE FILED BY AMENDMENT]
    
 
   
<TABLE>
<CAPTION>
                                             Seven-day         Effective
                 Fund Name                     Yield        Seven-day Yield
- ---------------------------------------------------------------------------
<S>                                          <C>            <C>
Janus Money Market Fund - Investor Shares          %                 %
Janus Government Money Market Fund -
  Investor Shares                                  %                 %
Janus Tax-Exempt Money Market Fund -
  Investor Shares*                                 %                 %
- ---------------------------------------------------------------------------
</TABLE>
    
 
   
*Janus Tax-Exempt Money Market Fund Investor Shares' tax equivalent yield for
 the seven day period ended October 31, 1997 was     %.
    
 
     Although published yield information is useful to investors in reviewing a
Fund's performance, investors should be aware that the Fund's yield fluctuates
from day to day and that the Fund's yield for any given period is not an
indication or representation by the Fund of future yields or rates of return on
the Shares. Also, Processing Organizations may charge their customers direct
fees in connection with an investment in a Fund, which will have the effect of
reducing the Fund's net yield to those shareholders. The yield on a class of
Shares is not fixed or guaranteed, and an investment in the Shares is not
insured. Accordingly, yield information may not necessarily be used to compare
Shares with investment alternatives which, like money market instruments or bank
accounts, may provide a fixed rate of interest. In addition, because investments
in the Funds are not insured or guaranteed, yield on the Shares may not
necessarily be used to compare the Shares with investment alternatives which are
insured or guaranteed.
 
                                DETERMINATION OF
                                NET ASSET VALUE
 
   
     Pursuant to the rules of the SEC, the Trustees have established procedures
to stabilize each Fund's net asset value at $1.00 per Share. These procedures
include a review of the extent of any deviation of net asset value per Share as
a result of fluctuating interest rates, based on available market rates, from
the Fund's $1.00 amortized cost price per Share. Should that deviation exceed
1/2 of 1%, the Trustees will consider whether any action should be initiated to
eliminate or reduce material dilution
    
 
                                       11
<PAGE>   
 
or other unfair results to shareholders. Such action may include redemption of
Shares in kind, selling portfolio securities prior to maturity, reducing or
withholding dividends and utilizing a net asset value per Share as determined by
using available market quotations. Each Fund i) will maintain a dollar-weighted
average portfolio maturity of 90 days or less; ii) will not purchase any
instrument with a remaining maturity greater than 397 days or subject to a
repurchase agreement having a duration of greater than 397 days; iii) will limit
portfolio investments, including repurchase agreements, to those U.S.
dollar-denominated instruments that Janus Capital has determined present minimal
credit risks pursuant to procedures established by the Trustees; and iv) will
comply with certain reporting and recordkeeping procedures. The Trust has also
established procedures to ensure that portfolio securities meet the Funds' high
quality criteria.
 
                               INVESTMENT ADVISER
                               AND ADMINISTRATOR
 
     As stated in the Prospectus, each Fund has an Investment Advisory Agreement
with Janus Capital, 100 Fillmore Street, Denver, Colorado 80206-4928. Each
Advisory Agreement provides that Janus Capital will furnish continuous advice
and recommendations concerning the Funds' investments. The Funds have each
agreed to compensate Janus Capital for its advisory services by the monthly
payment of an advisory fee at the annual rate of .20% of the average daily net
assets of each Fund. However, Janus Capital has agreed to waive .10% of the
value of each Fund's average daily net assets of the advisory fee. Janus Capital
may modify or terminate the waiver at any time upon at least 90 days' notice to
the Trustees. In addition, the Funds pay brokerage commissions or dealer spreads
and other expenses in connection with the execution of portfolio transactions.
 
     On behalf of the Shares, each of the Funds has also entered into an
Administration Agreement with Janus Capital. Under the terms of the
Administration Agreements, each of the Funds has agreed to compensate Janus
Capital for administrative services at the annual rate of .50% of the value of
the average daily net assets of the Shares for certain services, including
custody, transfer agent fees and expenses, legal fees not related to litigation,
accounting expenses, net asset value determination and Fund accounting,
recordkeeping, and blue sky registration and monitoring services, registration
fees, expenses of shareholders' meetings and reports to shareholders, costs of
preparing, printing and mailing the Shares' Prospectuses and Statements of
Additional Information to current shareholders, and other costs of complying
with applicable laws regulating the sale of Shares. Each Fund will pay those
expenses not assumed by Janus Capital, including interest and taxes, fees and
expenses of Trustees who are not affiliated with Janus Capital, audit fees and
expenses, and extraordinary costs.
 
                                       12
<PAGE>   
 
     The following table summarizes the advisory fees paid by the Funds for the
fiscal years ended October 31:
   
[TO BE FILED BY AMENDMENT]
    
 
   
<TABLE>
<CAPTION>
                                1997                      1996                      1995
                       -----------------------   -----------------------   -----------------------
                        Advisory     Advisory     Advisory     Advisory     Advisory     Advisory
                       Fees Prior   Fees After   Fees Prior   Fees After   Fees Prior   Fees After
      Fund Name        to Waiver      Waiver     to Waiver      Waiver     to Waiver      Waiver
- --------------------------------------------------------------------------------------------------
<S>                    <C>          <C>          <C>          <C>          <C>          <C>
Janus Money Market
  Fund                 $            $            $3,101,530   $1,550,765    $874,302      $437,151
Janus Government
  Money Market Fund    $            $              $330,914     $165,457    $151,606       $75,803
Janus Tax-Exempt
  Money Market Fund    $            $              $140,898      $70,449     $82,622       $41,311
- --------------------------------------------------------------------------------------------------
</TABLE>
    
 
     The following table summarizes the administration fees paid by the Shares
for the fiscal years ended October 31:
   
[TO BE FILED BY AMENDMENT]
    
 
   
<TABLE>
<CAPTION>
                                       1997
                          -------------------------------
                          Administration   Administration          1996                 1995(1)
                            Fees Prior       Fees Prior     -------------------   -------------------
       Fund Name            to Waiver        to Waiver      Administration Fees   Administration Fees
- -----------------------------------------------------------------------------------------------------
<S>                       <C>              <C>              <C>                   <C>
Janus Money Market    
  Fund - Investor Shares    $                $                  $3,381,669                 $1,636,704
Janus Government Money
  Market Fund - Investor
  Shares                    $                $                    $560,294                   $311,887
Janus Tax-Exempt Money
  Market Fund - Investor
  Shares                    $                $                    $343,475                   $203,530
- -----------------------------------------------------------------------------------------------------
</TABLE>
    
 
(1) February 15, 1995 (inception) to October 31, 1995.
 
     Advisory fees are paid on the Fund level while administration fees are paid
on the class level.
 
   
     The Advisory Agreements for each Fund were reexecuted on July 1, 1997
(without amendment other than effective dates) and will continue in effect until
July 1, 1998, and thereafter from year to year so long as such continuance is
approved annually by a majority of the Trustees who are not parties to the
Advisory Agreements or interested persons of any such party, and by either a
majority of the outstanding voting shares or the Trustees of the Funds. Each
Advisory Agreement i) may be terminated without the payment of any penalty by
any Fund or Janus Capital on 60 days' written notice; ii) terminates
automatically in the event of its assignment; and iii) generally, may not be
amended without the approval of a majority of the Trustees of the affected Fund,
including the Trustees who are not interested persons of that Fund or Janus
Capital and, to the extent required by the 1940 Act, the vote of a majority of
the outstanding voting securities of that Fund.
    
 
     Janus Capital also performs investment advisory services for other mutual
funds, and for individual, charitable, corporate and retirement accounts.
Investment decisions for each account managed by Janus Capital, including the
Funds, are made independently
 
                                       13
<PAGE>   
 
from those for any other account that is or may in the future become managed by
Janus Capital or its affiliates. If, however, a number of accounts managed by
Janus Capital are contemporaneously engaged in the purchase or sale of the same
security, the orders may be aggregated and/or the transactions may be averaged
as to price and allocated equitably to each account. In some cases, this policy
might adversely affect the price paid or received by an account or the size of
the position obtained or liquidated for an account. Pursuant to an exemptive
order granted by the SEC, the Funds and other funds advised by Janus Capital may
also transfer daily uninvested cash balances into one or more joint trading
accounts. Assets in the joint trading accounts are invested in money market
instruments and the proceeds are allocated to the participating funds on a pro
rata basis.
 
     Each account managed by Janus Capital has its own investment objective and
is managed in accordance with that objective by a particular portfolio manager
or team of portfolio managers. As a result, from time to time two or more
different managed accounts may pursue divergent investment strategies with
respect to investments or categories of investments.
 
     As indicated in the Prospectus, Janus Capital does not permit portfolio
managers to purchase and sell securities for their own accounts except under the
limited exceptions contained in Janus Capital's policy regarding personal
investing by directors, officers and employees of Janus Capital and the Funds.
The policy requires investment personnel and officers of Janus Capital, inside
directors of Janus Capital and the Funds and other designated persons deemed to
have access to current trading information to pre-clear all transactions in
securities not otherwise exempt under the policy. Requests for trading authority
will be denied when, among other reasons, the proposed personal transaction
would be contrary to the provisions of the policy or would be deemed to
adversely affect any transaction then known to be under consideration for or to
have been effected on behalf of any client account, including the Funds.
 
     In addition to the pre-clearance requirement described above, the policy
subjects investment personnel, officers and directors/Trustees of Janus Capital
and the Funds to various trading restrictions and reporting obligations. All
reportable transactions are reviewed for compliance with Janus Capital's policy.
Those persons also may be required under certain circumstances to forfeit their
profits made from personal trading.
 
     The provisions of the policy are administered by and subject to exceptions
authorized by Janus Capital.
 
     Kansas City Southern Industries, Inc., a publicly traded holding company
whose primary subsidiaries are engaged in transportation, information processing
and financial services ("KCSI"), owns approximately 83% of Janus Capital. Thomas
H. Bailey, the President and Chairman of the Board of Janus Capital, owns 12% of
its voting stock and, by agreement with KCSI, selects a majority of Janus
Capital's Board.
 
                                       14
<PAGE>   
 
                           CUSTODIAN, TRANSFER AGENT
                            AND CERTAIN AFFILIATIONS
 
   
     UMB Bank, N.A., P.O. Box 419226, Kansas City, Missouri 64141-6226, is the
Funds' custodian. The custodian holds the Funds' assets in safekeeping and
collects and remits the income thereon, subject to the instructions of each
Fund.
    
 
     Janus Service Corporation ("Janus Service"), P.O. Box 173375, Denver,
Colorado 80217-3375, a wholly-owned subsidiary of Janus Capital, is the Funds'
transfer agent. In addition, Janus Service provides certain other
administrative, recordkeeping and shareholder relations services to the Funds.
The Funds do not pay Janus Service a fee.
 
     Janus Distributors, Inc. ("Janus Distributors"), 100 Fillmore Street,
Denver, Colorado 80206-4928, a wholly-owned subsidiary of Janus Capital, is a
distributor of the Funds. Janus Distributors is registered as a broker-dealer
under the Securities Exchange Act of 1934 (the "Exchange Act") and is a member
of the National Association of Securities Dealers, Inc. Janus Distributors acts
as the agent of the Funds in connection with the sale of their shares in all
states in which the shares are registered and in which Janus Distributors is
qualified as a broker-dealer. Under the Distribution Agreement, Janus
Distributors continuously offers the Funds' shares and accepts orders at net
asset value. No sales charges are paid by investors. Promotional expenses in
connection with offers and sales of shares are paid by Janus Capital.
 
     Janus Capital also may make payments to selected broker-dealer firms or
institutions which were instrumental in the acquisition of shareholders for the
Funds or which performed services with respect to shareholder accounts. The
minimum aggregate size required for eligibility for such payments, and the
factors in selecting the broker-dealer firms and institutions to which they will
be made, are determined from time to time by Janus Capital.
 
                             PORTFOLIO TRANSACTIONS
                                 AND BROKERAGE
 
     Decisions as to the assignment of portfolio business for the Funds and
negotiation of its commission rates are made by Janus Capital whose policy is to
obtain the "best execution" (prompt and reliable execution at the most favorable
security price) of all portfolio transactions.
 
     In selecting brokers and dealers and in negotiating commissions, Janus
Capital considers a number of factors, including but not limited to: Janus
Capital's knowledge of currently available negotiated commission rates or prices
of securities currently available and other current transaction costs; the
nature of the security being traded; the size and type of the transaction; the
nature and character of the markets for the security to be purchased or sold;
the desired timing of the trade; the activity existing and expected in the
market for the particular security; confidentiality; the quality of the
execution, clearance and settlement services; financial stability of the broker
or dealer; the existence of actual or apparent operational problems of any
broker or dealer; and research products or services provided. In recognition of
the value of the foregoing
 
                                       15
<PAGE>   
 
factors, Janus Capital may place portfolio transactions with a broker or dealer
with whom it has negotiated a commission that is in excess of the commission
another broker or dealer would have charged for effecting that transaction if
Janus Capital determines in good faith that such amount of commission was
reasonable in relation to the value of the brokerage and research provided by
such broker or dealer viewed in terms of either that particular transaction or
of the overall responsibilities of Janus Capital. These research and other
services may include, but are not limited to, general economic and security
market reviews, industry and company reviews, evaluations of securities,
recommendations as to the purchase and sale of securities, and access to third
party publications, computer and electronic equipment and software. Research
received from brokers or dealers is supplemental to Janus Capital's own research
efforts.
 
   
     For the fiscal year ended October 31, 1997, the total brokerage commissions
paid by the Funds to brokers and dealers in transactions identified for
execution primarily on the basis of research and other services provided to the
Funds are summarized below:
    
   
[TO BE FILED BY AMENDMENT]
    
 
   
<TABLE>
<CAPTION>
               Fund Name                  Commissions         Transactions
- --------------------------------------------------------------------------
<S>                                       <C>                 <C>
Janus Money Market Fund                      $                     $
Janus Government Money Market Fund           $                     $
Janus Tax-Exempt Money Market Fund           $                     $
- --------------------------------------------------------------------------
</TABLE>
    
 
   
     For the fiscal years ended October 31, 1997, October 31, 1996 and October
31, 1995, the total brokerage commissions paid by the Funds are summarized
below:
    
   
[TO BE FILED BY AMENDMENT]
    
 
   
<TABLE>
<CAPTION>
                 Fund Name                      1997        1996       1995
- ---------------------------------------------------------------------------
<S>                                            <C>         <C>         <C>
Janus Money Market Fund                          $         $4,851      $0
Janus Government Money Market Fund               $           $0        $0
Janus Tax-Exempt Money Market Fund               $           $0        $0
- ---------------------------------------------------------------------------
</TABLE>
    
 
     The Funds generally buy and sell securities in principal transactions, in
which no commissions are paid. However, the Funds may engage an agent and pay
commissions for such transactions if Janus Capital believes that the net result
of the transaction to the respective Fund will be no less favorable than that of
contemporaneously available principal transactions.
 
     Janus Capital may use research products and services in servicing other
accounts in addition to the Funds. If Janus Capital determines that any research
product or service has a mixed use, such that it also serves functions that do
not assist in the investment decision-making process, Janus Capital may allocate
the costs of such service or product accordingly. Only that portion of the
product or service that Janus Capital determines will assist it in the
investment decision-making process may be paid for in brokerage commission
dollars. Such allocation may create a conflict of interest for Janus Capital.
 
     Janus Capital may consider sales of Shares by a broker-dealer or the
recommendation of a broker-dealer to its customers that they purchase Shares as
a factor in the selection of broker-dealers to execute Fund portfolio
transactions. Janus Capital may also consider payments made by brokers effecting
transactions for a Fund (i) to the Fund or (ii) to other persons on behalf of
the Fund for services provided to the Fund
 
                                       16
<PAGE>   
 
for which it would be obligated to pay. In placing portfolio business with such
broker-dealers, Janus Capital will seek the best execution of each transaction.
 
     When the Funds purchase or sell a security in the over-the-counter market,
the transaction takes place directly with a principal market-maker, without the
use of a broker, except in those circumstances where in the opinion of Janus
Capital better prices and executions will be achieved through the use of a
broker.
 
   
     As of October 31, 1997, certain Funds owned securities of their regular
broker-dealers (or parents), as shown below:
    
   
[TO BE FILED BY AMENDMENT]
    
 
   
<TABLE>
<CAPTION>
                                                                  Value of
                                        Name of                  Securities
       Fund Name                     Broker-Dealer                 Owned
- ----------------------------------------------------------------------------
<S>                      <C>                                    <C>
</TABLE>
    
 
                             OFFICERS AND TRUSTEES
 
     The following are the names of the Trustees and officers of the Trust,
together with a brief description of their principal occupations during the last
five years.
 
Thomas H. Bailey*# - Trustee, Chairman and President
100 Fillmore Street
Denver, CO 80206-4928
     Trustee, Chairman and President of Janus Aspen Series. Chairman, Chief
     Executive Officer, Director and President of Janus Capital. Chairman and
     Director of IDEX Management, Inc., Largo, Florida (50% subsidiary of Janus
     Capital and investment adviser to a group of mutual funds) ("IDEX").
 
James P. Craig, III*# - Trustee
100 Fillmore Street
Denver, CO 80206-4928
   
     Trustee and Executive Vice President of Janus Aspen Series. Chief
     Investment Officer, Vice President and Director of Janus Capital. Executive
     Vice President and Portfolio Manager of Janus Fund. Executive Vice
     President and Co-Manager of Janus Venture Fund.
    
 
Sharon S. Pichler* - Executive Vice President
100 Fillmore Street
Denver, CO 80206-4928
     Executive Vice President and Portfolio Manager of Janus Money Market Fund,
     Janus Tax-Exempt Money Market Fund and Janus Government Money Market Fund.
     Vice President of Janus Capital. Formerly, Assistant Vice President and
     Portfolio Manager at USAA Investment Management Co. (1990-1994).
 
- --------------------------------------------------------------------------------
*Interested person of the Trust and of Janus Capital.
#Member of the Trust's Executive Committee.
 
                                       17
<PAGE>   
 
   
Steven R. Goodbarn* - Vice President and Chief Financial Officer
100 Fillmore Street
Denver, CO 80206-4928
    
   
     Vice President and Chief Financial Officer of Janus Aspen Series. Vice
     President of Finance, Treasurer and Chief Financial Officer of Janus
     Service, Janus Distributors and Janus Capital. Director of IDEX, Janus
     Service and Janus Distributors. Director, Treasurer and Vice President of
     Finance of Janus Capital International Ltd. Formerly (May 1992-January
     1996), Treasurer of Janus Investment Fund and Janus Aspen Series.
    
 
Glenn P. O'Flaherty* - Treasurer and Chief Accounting Officer
100 Fillmore Street
Denver, CO 80206-4928
     Treasurer and Chief Accounting Officer of Janus Aspen Series. Director of
     Fund Accounting of Janus Capital.
 
Kelley Abbott Howes* - Secretary
100 Fillmore Street
Denver, CO 80206-4928
   
     Secretary of Janus Aspen Series. Director and President of Janus
     Distributors. Associate Counsel of Janus Capital. Formerly (1990 to 1994),
     with The Boston Company Advisors, Inc., Boston Massachusetts (mutual fund
     administration services).
    
 
   
William D. Stewart# - Trustee
5330 Sterling Drive
Boulder, CO 80302
    
   
     Trustee of Janus Aspen Series. President of HPS Division of MKS
     Instruments, Boulder, Colorado (manufacturer of vacuum fittings and
     valves).
    
 
   
Gary O. Loo# - Trustee
102 N. Cascade Avenue, Suite 500
Colorado Springs, CO 80903
    
     Trustee of Janus Aspen Series. President and a Director of High Valley
     Group, Inc., Colorado Springs, Colorado (investments).
 
   
Dennis B. Mullen - Trustee
14103 Denver West Parkway
Golden, CO 80401
    
   
     Trustee of Janus Aspen Series. Chief Financial Officer-Boston Market
     Concepts, Boston Chicken, Inc., Golden, Colorado (restaurant chain).
     Formerly (1993-1997), President and Chief Executive Officer of BC
     Northwest, L.P., a franchise of Boston Chicken, Inc., Bellevue, Washington
     (restaurant chain).
    
 
- --------------------------------------------------------------------------------
   
*Interested person of the Trust and of Janus Capital.
    
   
#Member of the Trust's Executive Committee.
    
 
                                       18
<PAGE>   
 
Martin H. Waldinger - Trustee
4940 Sandshore Court
San Diego, CA 92130
   
     Trustee of Janus Aspen Series. Private Consultant. Formerly (1993 to 1996),
     Director of Run Technologies, Inc., a software development firm, San
     Carlos, California. Formerly (1989 to 1993), President and Chief Executive
     Officer of Bridgecliff Management Services, Campbell, California (a
     condominium association management company).
    
 
James T. Rothe -- Trustee
102 South Tejon Street, Suite 1100
Colorado Springs, CO 80903
     Trustee of Janus Aspen Series. Professor of Business, University of
     Colorado, Colorado Springs, Colorado. Principal, Phillips-Smith Retail
     Group, Colorado Springs, Colorado (a venture capital firm). Formerly
     (1986-1994), Dean of the College of Business, University of Colorado,
     Colorado Springs, Colorado.
 
     The Trustees are responsible for major decisions relating to each Fund's
objective, policies and techniques. The Trustees also supervise the operation of
the Funds by their officers and review the investment decisions of the officers
although they do not actively participate on a regular basis in making such
decisions.
 
   
     The Trust's Executive Committee shall have and may exercise all the powers
and authority of the Trustees except for matters requiring action by all
Trustees pursuant to the Trust's Bylaws or Declaration of Trust, Massachusetts
Law or the 1940 Act.
    
 
   
     The Money Market Funds Committee, consisting of Messrs. Loo, Mullen and
Rothe, monitors the compliance with policies and procedures adopted particularly
for money market funds.
    
 
     The following table shows the aggregate compensation earned by and paid to
each Trustee by the Funds described in this SAI and all funds advised and
sponsored by Janus Capital (collectively, the "Janus Funds") for the periods
indicated. None of the Trustees receive any pension or retirement benefits from
the Funds or the Janus Funds.
 
   
<TABLE>
<CAPTION>
                           AGGREGATE COMPENSATION      TOTAL COMPENSATION
                             FROM THE FUNDS FOR     FROM THE JANUS FUNDS FOR
                             FISCAL YEAR ENDED         CALENDAR YEAR ENDED
                              OCTOBER 31, 1997         DECEMBER 31, 1997**
                              [TO BE FILED BY            [TO BE FILED BY
NAME OF PERSON, POSITION         AMENDMENT]                AMENDMENT]
- -----------------------------------------------------------------------------
<S>                        <C>                      <C>
Thomas H. Bailey,
  Chairman*                      $                         $
James P. Craig, III,
  Trustee*                       $                         $
William D. Stewart,
  Trustee                        $                         $
Gary O. Loo, Trustee             $                         $
Dennis B. Mullen, Trustee        $                         $
Martin H. Waldinger,
  Trustee                        $                         $
James T. Rothe, Trustee          $                         $
- -----------------------------------------------------------------------------
</TABLE>
    
 
 *An interested person of the Funds and of Janus Capital. Compensated by Janus
  Capital and not the Funds.
   
**As of December 31, 1997, Janus Funds consisted of two registered investment
  companies comprised of a total of 32 funds.
    
 
                                       19
<PAGE>   
 
                               PURCHASE OF SHARES
 
     As stated in the Prospectus, Janus Distributors is a distributor of the
Funds' shares. Shares are sold at the net asset value per share as determined at
the close of the regular trading session of the New York Stock Exchange (the
"NYSE" or the "Exchange") next occurring after a purchase order is received and
accepted by a Fund. A Fund's net asset value is calculated each day that both
the NYSE and the New York Federal Reserve Bank are open. As stated in the
Prospectus, the Funds each seek to maintain a stable net asset value per share
of $1.00. The Shareholder's Manual Section of the Prospectus contains detailed
information about the purchase of Shares.
 
REINVESTMENT OF DIVIDENDS AND DISTRIBUTIONS
   
     If investors do not elect in writing or by phone to receive their dividends
and distributions in cash, all income dividends and capital gains distributions,
if any, on Shares are reinvested automatically in additional Shares of that Fund
at the NAV determined on the first business day following the record date.
Checks for cash dividends and distributions and confirmations of reinvestments
are usually mailed to shareholders within ten days after the record date. Any
election (which may be made on the New Account Application form or by phone)
will apply to dividends and distributions the record dates of which fall on or
after the date that a Fund receives such notice. Changes to distribution options
must be received at least three days prior to the record date to be effective
for such date. Investors receiving cash distributions and dividends may elect in
writing or by phone to change back to automatic reinvestment at any time.
    
 
                              REDEMPTION OF SHARES
 
     Procedures for redemption of Shares are set forth in the Shareholder's
Manual section of the Prospectus. Shares normally will be redeemed for cash,
although each Fund retains the right to redeem Shares in kind under unusual
circumstances, in order to protect the interests of remaining shareholders, by
delivery of securities selected from its assets at its discretion. However, the
Funds are governed by Rule 18f-1 under the 1940 Act, which requires each Fund to
redeem Shares solely in cash up to the lesser of $250,000 or 1% of the net asset
value of that Fund during any 90-day period for any one shareholder. Should
redemptions by any shareholder exceed such limitation, their Fund will have the
option of redeeming the excess in cash or in kind. If Shares are redeemed in
kind, the redeeming shareholder might incur brokerage costs in converting the
assets to cash. The method of valuing securities used to make redemptions in
kind will be the same as the method of valuing portfolio securities described
under "Determination of Net Asset Value" and such valuation will be made as of
the same time the redemption price is determined.
 
   
     The right to require the Funds to redeem Shares may be suspended, or the
date of payment may be postponed, whenever (1) trading on the NYSE is
restricted, as determined by the SEC, or the NYSE is closed except for holidays
and weekends, (2) the SEC permits such suspension and so orders, or (3) an
emergency exists as
    
 
                                       20
<PAGE>   
 
   
determined by the SEC so that disposal of securities or determination of NAV is
not reasonably practicable.
    
 
                              SHAREHOLDER ACCOUNTS
 
     Detailed information about the general procedures for shareholder accounts
and specific types of accounts is set forth in the Prospectus. Applications for
specific types of accounts may be obtained by calling the Funds at
1-800-525-3713 or writing to the Funds at P.O. Box 173375, Denver, Colorado
80217-3375.
 
SYSTEMATIC REDEMPTIONS
   
     As stated in the Shareholder's Manual section of the Prospectus, if you
have a regular account or are eligible for distributions from a retirement plan,
you may establish a systematic redemption option. The payments will be made from
the proceeds of periodic redemptions of Shares in the account at the net asset
value. Depending on the size or frequency of the disbursements requested, and
the fluctuation in value of the Shares in the Fund's portfolio, redemptions for
the purpose of making such disbursements may reduce or even exhaust the
shareholder's account. Either an investor or their Fund, by written notice to
the other, may terminate the investor's systematic redemption option without
penalty at any time.
    
 
     Information about requirements to establish a systematic redemption option
may be obtained by writing or calling the Funds at the address or phone number
shown above.
 
   
                             TAX-DEFERRED ACCOUNTS
    
 
   
     The Funds offer several different types of tax-deferred retirement plans
that an investor may establish to invest in Shares, depending on rules
prescribed by the Internal Revenue Code of 1986 and the regulations thereunder
(the "Code"). Regular and Roth Individual Retirement Accounts ("IRAs") may be
used by most individuals who have taxable compensation. Simplified Employee
Pensions ("SEPs") and the Defined Contribution Plans may be used by most
employers, including corporations, partnerships and sole proprietors, for the
benefit of business owners and their employees. Education IRAs allow
individuals, subject to certain income limitations, to contribute up to $500
annually on behalf of any child under the age of 18. In addition, the Funds
offer a Section 403(b)(7) Plan for employees of educational organizations and
other qualifying tax-exempt organizations. Investors should consult their tax
advisor or legal counsel before selecting a tax-deferred account.
    
 
   
     Contributions under Regular and Roth IRAs, Education IRAs, SEPs, Defined
Contribution Plans (Profit Sharing or Money Purchase Pension Plans) and Section
403(b)(7) Plans are subject to specific contribution limitations. Generally,
such contributions may be invested at the direction of the participant. The
investment is then held by Investors Fiduciary Trust Company as custodian. Each
participant's account is charged an annual fee of $12. There is a maximum annual
fee of $24 per taxpayer identification number.
    
 
                                       21
<PAGE>   
 
   
     Distributions from tax deferred accounts may be subject to ordinary income
tax and may be subject to an additional 10% tax if withdrawn prior to age 59 1/2
or used for a nonqualifying purpose. Several exceptions to the general rule may
apply. Additionally, shareholders generally must start withdrawing retirement
plan assets no later than April 1 of the year after they reach age 70 1/2.
Several exceptions to these general rules may apply and several methods exist to
determine the amount and timing of the minimum annual distribution (if any).
Shareholders should consult with their tax advisor or legal counsel prior to
receiving any distribution from any tax-deferred plan, in order to determine the
income tax impact of any such distribution.
    
 
   
     To receive additional information about Regular and Roth IRAs, SEPs,
Defined Contribution Plans and Section 403(b)(7) Plans along with the necessary
materials to establish an account, please call the Funds at 1-800-525-3713 or
write to the Funds at P.O. Box 173375, Denver, Colorado 80217-3375. No
contribution to a Regular or Roth IRA, SEP, Defined Contribution Plan or Section
403(b)(7) Plan can be made until the appropriate forms to establish any such
plan have been completed.
    
 
                            DIVIDENDS AND TAX STATUS
 
   
     Dividends representing substantially all of the net investment income and
any net realized gains on sales of securities are declared daily, Saturdays,
Sundays and holidays included, and distributed on the last business day of each
month. If a month begins on a Saturday, Sunday, or holiday, dividends for those
days are declared at the end of the preceding month and distributed on the first
business day of the month. A shareholder may receive dividends in cash or may
choose to have dividends automatically reinvested in a Fund's Shares. As
described in the Prospectus, Shares purchased by wire on a bank business day
will receive that day's dividend if the purchase is effected at or prior to 3:00
p.m. (New York time) for Janus Money Market Fund and Janus Government Money
Market Fund and 12:00 p.m. (New York time) for Janus Tax-Exempt Money Market
Fund. Otherwise, such Shares will begin to accrue dividends on the following
day. Orders for purchase accompanied by a check or other negotiable bank draft
will be accepted and effected as of 4:00 p.m. (New York time) on the day of
receipt and such Shares will begin to accrue dividends on the first bank
business day following receipt of the order. Requests for redemption of Shares
of a Fund will be redeemed at the next determined net asset value. If processed
by 4:00 p.m. (New York time) such redemption will generally include dividends
declared through the day of redemption. However, redemption requests made by
wire that are received prior to 3:00 p.m. (New York time) for Janus Money Market
Fund and Janus Government Money Market Fund and 12:00 p.m. (New York time) for
Janus Tax-Exempt Money Market Fund will result in Shares being redeemed that day
and no dividend will be accrued for such day. Proceeds of such a redemption will
normally be sent to the predesignated bank account on that day, but that day's
dividend will not be received. If shares of a Fund were originally purchased by
check or through an Automated Clearing House transaction, the Fund may delay
transmittal of redemption proceeds up to 15 days in order to ensure that
purchase funds have been collected. Closing times for purchase and redemption of
Shares may be changed for days in which the bond market or the NYSE close early.
    
 
                                       22
<PAGE>   
 
     Distributions for all of the Funds (except Janus Tax-Exempt Money Market
Fund) are taxable income and are subject to federal income tax (except for
shareholders exempt from income tax), whether such distributions are received in
cash or are reinvested in additional Shares. Full information regarding the tax
status of income dividends and any capital gains distributions will be mailed to
shareholders for tax purposes on or before January 31st of each year. As
described in detail in the Prospectus, Janus Tax-Exempt Money Market Fund
anticipates that substantially all income dividends it pays will be exempt from
federal income tax, although dividends attributable to interest on taxable
investments, together with distributions from any net realized short- or
long-term capital gains, are taxable.
 
     The Funds intend to qualify as regulated investment companies by satisfying
certain requirements prescribed by Subchapter M of the Code.
 
   
     Some money market securities employ a trust or other similar structure to
modify the maturity, price characteristics, or quality of financial assets. For
example, put features can be used to modify the maturity of a security, or
interest rate adjustment features can be used to enhance price stability. If the
structure does not perform as intended, adverse tax or investment consequences
may result. Neither the Internal Revenue Service nor any other regulatory
authority has ruled definitively on certain legal issues presented by structured
securities. Future tax or other regulatory determinations could adversely affect
the value, liquidity, or tax treatment of the income received from these
securities or the nature and timing of distributions made by a Fund.
    
 
                             PRINCIPAL SHAREHOLDERS
 
   
     [TO BE FILED BY AMENDMENT]
    
 
                           MISCELLANEOUS INFORMATION
 
   
     Each Fund is a series of the Trust, a Massachusetts business trust that was
created on February 11, 1986. The Trust is an open-end management investment
company registered under the 1940 Act. As of the date of this SAI, the Trust
consists of 19 separate series, three of which currently offer three classes of
shares. The Funds were added to the Trust as separate series on December 9,
1994.
    
 
     Janus Capital reserves the right to the name "Janus." In the event that
Janus Capital does not continue to provide investment advice to the Funds, the
Funds must cease to use the name "Janus" as soon as reasonably practicable.
 
     Under Massachusetts law, shareholders of the Funds could, under certain
circumstances, be held liable for the obligations of their Fund. However, the
Agreement and Declaration of Trust (the "Declaration of Trust") disclaims
shareholder liability for acts or obligations of the Funds and requires that
notice of this disclaimer be given in each agreement, obligation or instrument
entered into or executed by the Funds or the Trustees. The Declaration of Trust
also provides for indemnification from the assets of the Funds for all losses
and expenses of any Fund shareholder held liable for the obligations of their
Fund. Thus, the risk of a shareholder incurring a financial loss on
 
                                       23
<PAGE>   
 
account of its liability as a shareholder of one of the Funds is limited to
circumstances in which their Fund would be unable to meet its obligations. The
possibility that these circumstances would occur is remote. The Trustees intend
to conduct the operations of the Funds to avoid, to the extent possible,
liability of shareholders for liabilities of their Fund.
 
SHARES OF THE TRUST
     The Trust is authorized to issue an unlimited number of shares of
beneficial interest with a par value of one cent per share for each series of
the Trust. Shares of each Fund are fully paid and nonassessable when issued. All
shares of a Fund participate equally in dividends and other distributions by
such Fund, and in residual assets of that Fund in the event of liquidation.
Shares of each Fund have no preemptive, conversion or subscription rights.
 
   
     The Trust is authorized to issue multiple classes of shares for each Fund.
Currently, Janus Money Market Fund, Janus Government Money Market Fund and Janus
Tax-Exempt Money Market Fund each offer three classes of shares by separate
prospectuses. The Shares discussed in this SAI are offered to the general
public. A second class of shares, Service Shares, is offered through banks and
other financial institutions that meet minimum investment requirements in
connection with trust accounts, cash management programs and similar programs. A
third class of shares, Institutional Shares, is offered only to clients meeting
certain minimum investment criteria.
    
 
VOTING RIGHTS
     The present Trustees were elected at a meeting of shareholders held on July
10, 1992 with the exception of Mr. Craig and Mr. Rothe who were appointed by the
Trustees as of June 30, 1995 and January 1, 1997, respectively. Under the
Declaration of Trust, each Trustee will continue in office until the termination
of the Trust or his earlier death, retirement, resignation, bankruptcy,
incapacity or removal. Vacancies will be filled by a majority of the remaining
Trustees, subject to the 1940 Act. Therefore, no annual or regular meetings of
shareholders normally will be held, unless otherwise required by the Declaration
of Trust or the 1940 Act. Subject to the foregoing, shareholders have the power
to vote to elect or remove Trustees, to terminate or reorganize their Fund, to
amend the Declaration of Trust, to bring certain derivative actions and on any
other matters on which a shareholder vote is required by the 1940 Act, the
Declaration of Trust, the Trust's Bylaws or the Trustees.
 
     Each share of each series of the Trust has one vote (and fractional votes
for fractional shares). Shares of all series of the Trust have noncumulative
voting rights, which means that the holders of more than 50% of the shares of
all series of the Trust voting for the election of Trustees can elect 100% of
the Trustees if they choose to do so and, in such event, the holders of the
remaining shares will not be able to elect any Trustees. Each series or class of
the Trust will vote separately only with respect to those matters that affect
only that series or class or if the interest of the series or class in the
matter differs from the interests of other series or classes of the Trust.
 
                                       24
<PAGE>   
 
INDEPENDENT ACCOUNTANTS
     Price Waterhouse LLP, 950 Seventeenth Street, Suite 2500, Denver, Colorado
80202, independent accountants for the Funds, audit the Funds' annual financial
statements and prepare their tax returns.
 
REGISTRATION STATEMENT
   
     The Trust has filed with the SEC, Washington, D.C., a Registration
Statement under the Securities Act of 1933, as amended, with respect to the
securities to which this SAI relates. If further information is desired with
respect to the Funds or such securities, reference is made to the Registration
Statement and the exhibits filed as a part thereof.
    
 
                              FINANCIAL STATEMENTS
 
   
     The following audited financial statements of the Funds for the period
ended October 31, 1997 are hereby incorporated into this SAI by reference to the
Funds' Annual Report dated October 31, 1997. A copy of such report accompanies
this SAI.
    
 
DOCUMENTS INCORPORATED BY REFERENCE TO THE ANNUAL REPORT
 
   
     [TO BE FILED BY AMENDMENT]
    
 
   
     Schedules of Investments as of October 31, 1997
    
 
   
     Statements of Operations for the period ended October 31, 1997
    
 
   
     Statements of Assets and Liabilities as of October 31, 1997
    
 
   
     Statements of Changes in Net Assets for the periods ended October 31, 1997
       and 1996
    
 
     Financial Highlights for each of the periods indicated
 
     Notes to Financial Statements
 
     Report of Independent Accountants
 
     The portions of such Annual Report that are not specifically listed above
are not incorporated by reference into this SAI and are not part of the
Registration Statement.
 
                                       25
<PAGE>   
 
                                   APPENDIX A
 
DESCRIPTION OF SECURITIES RATINGS
 
MOODY'S AND STANDARD AND POOR'S
 
MUNICIPAL AND CORPORATE BONDS AND MUNICIPAL LOANS
     The two highest ratings of Standard & Poor's Ratings Services ("S&P") for
municipal and corporate bonds are AAA and AA. Bonds rated AAA have the highest
rating assigned by S&P to a debt obligation. Capacity to pay interest and repay
principal is extremely strong. Bonds rated AA have a very strong capacity to pay
interest and repay principal and differ from the highest rated issues only in a
small degree. The AA rating may be modified by the addition of a plus (+) or
minus (-) sign to show relative standing within that rating category.
 
     The two highest ratings of Moody's Investors Service, Inc. ("Moody's") for
municipal and corporate bonds are Aaa and Aa. Bonds rated Aaa are judged by
Moody's to be of the best quality. Bonds rated Aa are judged to be of high
quality by all standards. Together with the Aaa group, they comprise what are
generally known as high-grade bonds. Moody's states that Aa bonds are rated
lower than the best bonds because margins of protection or other elements make
long-term risks appear somewhat larger than Aaa securities. The generic rating
Aa may be modified by the addition of the numerals 1, 2 or 3. The modifier 1
indicates that the security ranks in the higher end of the Aa rating category;
the modifier 2 indicates a mid-range ranking; and the modifier 3 indicates that
the issue ranks in the lower end of such rating category.
 
SHORT-TERM MUNICIPAL LOANS
     S&P's highest rating for short-term municipal loans is SP-1. S&P states
that short-term municipal securities bearing the SP-1 designation have a strong
capacity to pay principal and interest. Those issues rated SP-1 which are
determined to possess a very strong capacity to pay debt service will be given a
plus (+) designation. Issues rated SP-2 have satisfactory capacity to pay
principal and interest with some vulnerability to adverse financial and economic
changes over the term of the notes.
 
     Moody's highest rating for short-term municipal loans is MIG-1/VMIG-1.
Moody's states that short-term municipal securities rated MIG-1/VMIG-1 are of
the best quality, enjoying strong protection from established cash flows of
funds for their servicing or from established and broad-based access to the
market for refinancing, or both. Loans bearing the MIG-2/VMIG-2 designation are
of high quality, with margins of protection ample although not so large as in
the MIG1/VMIG-1 group.
 
OTHER SHORT-TERM DEBT SECURITIES
     Prime-1 and Prime-2 are the two highest ratings assigned by Moody's for
other short-term debt securities and commercial paper, and A-1 and A-2 are the
two highest ratings for commercial paper assigned by S&P. Moody's uses the
numbers 1, 2 and 3 to denote relative strength within its highest classification
of Prime, while S&P uses the numbers 1, 2 and 3 to denote relative strength
within its highest classification of A. Issuers rated Prime-1 by Moody's have a
superior ability for repayment of senior short-term debt obligations and have
many of the following characteristics: leading market positions in
well-established industries, high rates of
 
                                       26
<PAGE>   
 
return on funds employed, conservative capitalization structure with moderate
reliance on debt and ample asset protection, broad margins in earnings coverage
of fixed financial charges and high internal cash generation, and well
established access to a range of financial markets and assured sources of
alternate liquidity. Issuers rated Prime-2 by Moody's have a strong ability for
repayment of senior short-term debt obligations and display many of the same
characteristics displayed by issuers rated Prime-1, but to a lesser degree.
Issuers rated A-1 by S&P carry a strong degree of safety regarding timely
repayment. Those issues determined to possess extremely strong safety
characteristics are denoted with a plus (+) designation. Issuers rated A-2 by
S&P carry a satisfactory degree of safety regarding timely repayment.
 
FITCH
- --------------------------------------------------------------------------------
 
<TABLE>
<S>            <C>
F-1+           Exceptionally strong credit quality. Issues assigned this
               rating are regarded as having the strongest degree of
               assurance for timely payment.
F-1            Very strong credit quality. Issues assigned this rating
               reflect an assurance for timely payment only slightly
               less in degree than issues rated F-1+.
F-2            Good credit quality. Issues assigned this rating have a
               satisfactory degree of assurance for timely payments, but
               the margin of safety is not as great as the F-1+ and F-1
               ratings.
</TABLE>
 
DUFF & PHELPS INC.
- --------------------------------------------------------------------------------
 
<TABLE>
<S>            <C>
Duff 1+        Highest certainty of timely payment. Short-term
               liquidity, including internal operating factors and/or
               ready access to alternative sources of funds, is clearly
               outstanding, and safety is just below risk-free U.S.
               Treasury short-term obligations.
Duff 1         Very high certainty of timely payment. Liquidity factors
               are excellent and supported by good fundamental
               protection factors. Risk factors are minor.
Duff 1-        High certainty of timely payment. Liquidity factors are
               strong and supported by good fundamental protection
               factors. Risk factors are very small.
Duff 2         Good certainty of timely payment. Liquidity factors and
               company fundamentals are sound. Although ongoing funding
               needs may enlarge total financing requirements, access to
               capital markets is good. Risk factors are small.
</TABLE>
 
THOMSON BANKWATCH, INC.
- --------------------------------------------------------------------------------
 
<TABLE>
<S>            <C>
TBW-1          The highest category; indicates a very high degree of
               likelihood that principal and interest will be paid on a
               timely basis.
TBW-2          The second highest category; while the degree of safety
               regarding timely repayment of principal and interest is
               strong, the relative degree of safety is not as high as
               for issues rated TBW-1.
TBW-3          The lowest investment grade category; indicates that
               while more susceptible to adverse developments (both
               internal and external) than obligations with higher
               ratings, capacity to service principal and interest in a
               timely fashion is considered adequate.
TBW-4          The lowest rating category; this rating is regarded as
               non-investment grade and therefore speculative.
</TABLE>
 
                                       27
<PAGE>   
 
IBCA, INC.
- --------------------------------------------------------------------------------
 
<TABLE>
<S>            <C>
A1+            Obligations supported by the highest capacity for timely
               repayment. Where issues possess a particularly strong
               credit feature, a rating of A1+ is assigned.
A2             Obligations supported by a good capacity for timely
               repayment.
A3             Obligations supported by a satisfactory capacity for
               timely repayment.
B              Obligations for which there is an uncertainty as to the
               capacity to ensure timely repayment.
C              Obligations for which there is a high risk of default or
               which are currently in default.
</TABLE>
 
- --------------------------------------------------------------------------------
 
                                       28
<PAGE>   
 
                                   APPENDIX B
 
DESCRIPTION OF MUNICIPAL SECURITIES
     MUNICIPAL NOTES generally are used to provide for short-term capital needs
and usually have maturities of one year or less. They include the following:
 
     1. PROJECT NOTES, which carry a U.S. government guarantee, are issued by
public bodies (called "local issuing agencies") created under the laws of a
state, territory, or U.S. possession. They have maturities that range up to one
year from the date of issuance. Project Notes are backed by an agreement between
the local issuing agency and the Federal Department of Housing and Urban
Development. These Notes provide financing for a wide range of financial
assistance programs for housing, redevelopment, and related needs (such as
low-income housing programs and renewal programs).
 
     2. TAX ANTICIPATION NOTES are issued to finance working capital needs of
municipalities. Generally, they are issued in anticipation of various seasonal
tax revenues, such as income, sales, use and business taxes, and are payable
from these specific future taxes.
 
     3. REVENUE ANTICIPATION NOTES are issued in expectation of receipt of other
types of revenues, such as Federal revenues available under the Federal Revenue
Sharing Programs.
 
     4. BOND ANTICIPATION NOTES are issued to provide interim financing until
long-term financing can be arranged. In most cases, the long-term bonds then
provide the money for the repayment of the Notes.
 
     5. CONSTRUCTION LOAN NOTES are sold to provide construction financing.
After successful completion and acceptance, many projects receive permanent
financing through the Federal Housing Administration under the Federal National
Mortgage Association ("Fannie Mae") or the Government National Mortgage
Association ("Ginnie Mae").
 
     6. TAX-EXEMPT COMMERCIAL PAPER is a short-term obligation with a stated
maturity of 365 days or less. It is issued by agencies of state and local
governments to finance seasonal working capital needs or as short-term financing
in anticipation of longer term financing.
 
     MUNICIPAL BONDS, which meet longer term capital needs and generally have
maturities of more than one year when issued, have three principal
classifications:
 
     1. GENERAL OBLIGATION BONDS are issued by such entities as states,
counties, cities, towns and regional districts. The proceeds of these
obligations are used to fund a wide range of public projects, including
construction or improvement of schools, highways and roads, and water and sewer
systems. The basic security behind General Obligation Bonds is the issuer's
pledge of its full faith and credit and taxing power for the payment of
principal and interest. The taxes that can be levied for the payment of debt
service may be limited or unlimited as to the rate or amount of special
assessments.
 
                                       29
<PAGE>   
 
     2. REVENUE BONDS in recent years have come to include an increasingly wide
variety of types of municipal obligations. As with other kinds of municipal
obligations, the issuers of revenue bonds may consist of virtually any form of
state or local governmental entity, including states, state agencies, cities,
counties, authorities of various kinds, such as public housing or redevelopment
authorities, and special districts, such as water, sewer or sanitary districts.
Generally, revenue bonds are secured by the revenues or net revenues derived
from a particular facility, group of facilities, or, in some cases, the proceeds
of a special excise or other specific revenue source. Revenue bonds are issued
to finance a wide variety of capital projects including electric, gas, water and
sewer systems; highways, bridges, and tunnels; port and airport facilities;
colleges and universities; and hospitals. Many of these bonds provide additional
security in the form of a debt service reserve fund to be used to make principal
and interest payments. Various forms of credit enhancement, such as a bank
letter of credit or municipal bond insurance, may also be employed in revenue
bond issues. Housing authorities have a wide range of security, including
partially or fully insured mortgages, rent subsidized and/or collateralized
mortgages, and/or the net revenues from housing or other public projects. Some
authorities provide further security in the form of a state's ability (without
obligation) to make up deficiencies in the debt service reserve fund.
 
     In recent years, revenue bonds have been issued in large volumes for
projects that are privately owned and operated (see 3 below).
 
     3. PRIVATE ACTIVITY BONDS are considered municipal bonds if the interest
paid thereon is exempt from Federal income tax and are issued by or on behalf of
public authorities to raise money to finance various privately operated
facilities for business and manufacturing, housing and health. These bonds are
also used to finance public facilities such as airports, mass transit systems
and ports. The payment of the principal and interest on such bonds is dependent
solely on the ability of the facility's user to meet its financial obligations
and the pledge, if any, of real and personal property as security for such
payment.
 
     While, at one time, the pertinent provisions of the Internal Revenue Code
permitted private activity bonds to bear tax-exempt interest in connection with
virtually any type of commercial or industrial project (subject to various
restrictions as to authorized costs, size limitations, state per capita volume
restrictions, and other matters), the types of qualifying projects under the
Code have become increasingly limited, particularly since the enactment of the
Tax Reform Act of 1986. Under current provisions of the Code, tax-exempt
financing remains available, under prescribed conditions, for certain privately
owned and operated rental multi-family housing facilities, nonprofit hospital
and nursing home projects, airports, docks and wharves, mass commuting
facilities and solid waste disposal projects, among others, and for the
refunding (that is, the tax-exempt refinancing) of various kinds of other
private commercial projects originally financed with tax-exempt bonds. In future
years, the types of projects qualifying under the Code for tax-exempt financing
are expected to become increasingly limited.
 
     Because of terminology formerly used in the Internal Revenue Code,
virtually any form of private activity bond may still be referred to as an
"industrial development bond," but more and more frequently revenue bonds have
become classified according
 
                                       30
<PAGE>   
 
to the particular type of facility being financed, such as hospital revenue
bonds, nursing home revenue bonds, multi-family housing revenues bonds, single
family housing revenue bonds, industrial development revenue bonds, solid waste
resource recovery revenue bonds, and so on.
 
     OTHER MUNICIPAL OBLIGATIONS, incurred for a variety of financing purposes,
include: municipal leases, which may take the form of a lease or an installment
purchase or conditional sale contract, are issued by state and local governments
and authorities to acquire a wide variety of equipment and facilities such as
fire and sanitation vehicles, telecommunications equipment and other capital
assets. Municipal leases frequently have special risks not normally associated
with general obligation or revenue bonds. Leases and installment purchase or
conditional sale contracts (which normally provide for title to the leased asset
to pass eventually to the government issuer) have evolved as a means for
governmental issuers to acquire property and equipment without meeting the
constitutional and statutory requirements for the issuance of debt. The
debt-issuance limitations of many state constitutions and statutes are deemed to
be inapplicable because of the inclusion in many leases or contracts of
"non-appropriation" clauses that provide that the governmental issuer has no
obligation to make future payments under the lease or contract unless money is
appropriated for such purpose by the appropriate legislative body on a yearly or
other periodic basis. To reduce this risk, the Fund will only purchase municipal
leases subject to a non-appropriation clause when the payment of principal and
accrued interest is backed by an unconditional irrevocable letter of credit, or
guarantee of a bank or other entity that meets the criteria described in the
Prospectus.
 
     Tax-exempt bonds are also categorized according to whether the interest is
or is not includible in the calculation of alternative minimum taxes imposed on
individuals, according to whether the costs of acquiring or carrying the bonds
are or are not deductible in part by banks and other financial institutions, and
according to other criteria relevant for Federal income tax purposes. Due to the
increasing complexity of Internal Revenue Code and related requirements
governing the issuance of tax-exempt bonds, industry practice has uniformly
required, as a condition to the issuance of such bonds, but particularly for
revenue bonds, an opinion of nationally recognized bond counsel as to the
tax-exempt status of interest on the bonds.
 
                                       31


<PAGE>   
 
                               JANUS VENTURE FUND
 
                              100 Fillmore Street
                             Denver, CO 80206-4928
                                 (800) 525-3713
 
                      STATEMENT OF ADDITIONAL INFORMATION
   
                               FEBRUARY 17, 1998
    
 
     Janus Venture Fund (the "Fund") is a no-load mutual fund that seeks capital
appreciation. The Fund normally invests at least 50% of its equity assets in
securities issued by small-sized companies. Small-sized companies are those who
have market capitalizations of less than $1 billion or annual gross revenues of
less than $500 million. Subject to this policy, the Fund may also invest in
larger issuers. Depending upon its portfolio managers' opinion of prevailing
market, financial and economic conditions, the Fund may at times hold
substantial positions in cash or interest-bearing securities.
 
     The Fund is a separate series of Janus Investment Fund, a Massachusetts
business trust (the "Trust"). Each series of the Trust represents shares of
beneficial interest in a separate portfolio of securities and other assets with
its own objective and policies. The Fund is managed by Janus Capital Corporation
("Janus Capital").
 
     The Fund has discontinued public sales of its shares to new investors.
However, shareholders who maintain open Fund accounts are permitted to continue
to purchase shares of the Fund and to reinvest any dividends and/or capital
gains distributions in shares of the Fund. Once a shareholder's Fund account is
closed, it may not be possible for that shareholder to purchase additional Fund
shares. See the "Shareholder's Manual" section of the Prospectus for more
details. The Fund may resume sales of its shares at some future date, although
it has no present intention of doing so.
 
   
     This Statement of Additional Information ("SAI") is not a Prospectus and
should be read in conjunction with the Fund's Prospectus dated February 17,
1998, which is incorporated by reference into this SAI and may be obtained from
the Trust at the above phone number or address. This SAI contains additional and
more detailed information about the Fund's operations and activities than the
Prospectus.
    
 
                                      LOGO
<PAGE>   
 
                               JANUS VENTURE FUND
                      STATEMENT OF ADDITIONAL INFORMATION
                               TABLE OF CONTENTS
 
Investment Policies, Restrictions and Techniques.............................. 3
     Investment Objective..................................................... 3
     Portfolio Policies....................................................... 3
     Investment Restrictions.................................................. 3
   
Types of Securities and Investment Techniques................................. 5
    
   
       Illiquid Investments................................................... 5
    
   
       Zero Coupon, Pay-In-Kind and Step Coupon Securities.................... 6
    
   
       Pass-Through Securities................................................ 6
    
   
       Investment Company Securities.......................................... 8
    
   
       Depositary Receipts.................................................... 8
    
   
       Municipal Obligations.................................................. 8
    
   
       Other Income-Producing Securities...................................... 9
    
   
       High-Yield/High-Risk Securities........................................ 9
    
   
       Repurchase and Reverse Repurchase Agreements.......................... 10
    
   
       Futures, Options and Other Derivative Instruments..................... 11
    
   
Investment Adviser........................................................... 23
    
   
Custodian, Transfer Agent and Certain Affiliations........................... 25
    
   
Portfolio Transactions and Brokerage......................................... 25
    
   
Officers and Trustees........................................................ 28
    
   
Purchase of Shares........................................................... 31
    
   
     Net Asset Value Determination........................................... 31
    
   
     Reinvestment of Dividends and Distributions............................. 32
    
   
Redemption of Shares......................................................... 32
    
   
Shareholder Accounts......................................................... 32
    
   
     Telephone Transactions.................................................. 33
    
   
     Systematic Redemptions.................................................. 33
    
   
Tax-Deferred Accounts........................................................ 33
    
   
Income Dividends, Capital Gains Distributions and Tax Status................. 34
    
   
Principal Shareholders....................................................... 35
    
   
Miscellaneous Information.................................................... 35
    
   
     Shares of the Trust..................................................... 35
    
   
     Voting Rights........................................................... 36
    
   
     Independent Accountants................................................. 36
    
   
     Registration Statement.................................................. 36
    
   
Performance Information...................................................... 36
    
   
Financial Statements......................................................... 37
    
   
Appendix A................................................................... 38
    
   
     Explanation of Rating Categories........................................ 38
    
- --------------------------------------------------------------------------------
 
                                        2
<PAGE>   
 
                              INVESTMENT POLICIES,
                          RESTRICTIONS AND TECHNIQUES
 
INVESTMENT OBJECTIVE
     As stated in the Prospectus, the Fund's investment objective is capital
appreciation. Realization of income is not a significant investment
consideration and any income realized on the Fund's investments therefore will
be incidental to the Fund's objective. There can be no assurance that the Fund
will, in fact, achieve its objective. The investment objective of the Fund is
not fundamental and may be changed by the Trustees without shareholder approval.
 
PORTFOLIO POLICIES
   
     The Prospectus discusses the types of securities in which the Fund will
invest, portfolio policies of the Fund and the investment techniques of the
Fund. The Prospectus includes a discussion of portfolio turnover policies. The
Fund's portfolio turnover rates (total purchases or sales, whichever is less,
compared to average monthly value of portfolio securities) for the fiscal years
ended October 31, 1997 and October 31, 1996, were   % and 136%, respectively.
    
 
INVESTMENT RESTRICTIONS
     As indicated in the Prospectus, the Fund is subject to certain fundamental
policies and restrictions that may not be changed without shareholder approval.
Shareholder approval means approval by the lesser of (i) more than 50% of the
outstanding voting securities of the Trust (or the Fund if a matter affects just
the Fund), or (ii) 67% or more of the voting securities present at a meeting if
the holders of more than 50% of the outstanding voting securities of the Trust
(or the Fund) are present or represented by proxy. As fundamental policies, the
Fund may not:
 
     (1) Own more than 10% of the outstanding voting securities of any one
issuer and, as to seventy-five percent (75%) of the value of its total assets,
purchase the securities of any one issuer (except cash items and "government
securities" as defined under the Investment Company Act of 1940, as amended (the
"1940 Act")), if immediately after and as a result of such purchase, the value
of the holdings of the Fund in the securities of such issuer exceeds 5% of the
value of the Fund's total assets.
 
     (2) Invest 25% or more of the value of its total assets in any particular
industry (other than U.S. government securities).
 
     (3) Invest directly in real estate or interests in real estate; however,
the Fund may own debt or equity securities issued by companies engaged in those
businesses.
 
     (4) Purchase or sell physical commodities other than foreign currencies
unless acquired as a result of ownership of securities (but this limitation
shall not prevent the Fund from purchasing or selling options, futures, swaps
and forward contracts or from investing in securities or other instruments
backed by physical commodities).
 
                                        3
<PAGE>   
 
     (5) Lend any security or make any other loan if, as a result, more than 25%
of its total assets would be lent to other parties (but this limitation does not
apply to purchases of commercial paper, debt securities or repurchase
agreements).
 
     (6) Act as an underwriter of securities issued by others, except to the
extent that the Fund may be deemed an underwriter in connection with the
disposition of portfolio securities of the Fund.
 
     As a fundamental policy, the Fund may, notwithstanding any other investment
policy or limitation (whether or not fundamental), invest all of its assets in
the securities of a single open-end management investment company with
substantially the same fundamental investment objective, policies and
limitations as the Fund.
 
     The Trustees have adopted additional investment restrictions for the Fund.
These restrictions are operating policies of the Fund and may be changed by the
Trustees without shareholder approval. The additional investment restrictions
adopted by the Trustees to date include the following:
 
     (a) The Fund will not (i) enter into any futures contracts and related
options for purposes other than bona fide hedging transactions within the
meaning of Commodity Futures Trading Commission ("CFTC") regulations if the
aggregate initial margin and premiums required to establish positions in futures
contracts and related options that do not fall within the definition of bona
fide hedging transactions will exceed 5% of the fair market value of the Fund's
net assets, after taking into account unrealized profits and unrealized losses
on any such contracts it has entered into; and (ii) enter into any futures
contracts if the aggregate amount of the Fund's commitments under outstanding
futures contracts positions would exceed the market value of its total assets.
 
     (b) The Fund does not currently intend to sell securities short, unless it
owns or has the right to obtain securities equivalent in kind and amount to the
securities sold short without the payment of any additional consideration
therefor, and provided that transactions in futures, options, swaps and forward
contracts are not deemed to constitute selling securities short.
 
     (c) The Fund does not currently intend to purchase securities on margin,
except that the Fund may obtain such short-term credits as are necessary for the
clearance of transactions, and provided that margin payments and other deposits
in connection with transactions in futures, options, swaps and forward contracts
shall not be deemed to constitute purchasing securities on margin.
 
     (d) The Fund may not mortgage or pledge any securities owned or held by the
Fund in amounts that exceed, in the aggregate, 15% of the Fund's net asset
value, provided that this limitation does not apply to reverse repurchase
agreements, deposits of assets to margin, guarantee positions in futures,
options, swaps or forward contracts, or the segregation of assets in connection
with such contracts.
 
     (e) The Fund may borrow money for temporary or emergency purposes (not for
leveraging or investment) in an amount not exceeding 25% of the value of its
total assets (including the amount borrowed) less liabilities (other than
borrowings). If borrowings exceed 25% of the value of the Fund's total assets by
reason of a decline in net assets, the Fund will reduce its borrowings within
three business days to the extent necessary to comply with the 25% limitation.
This policy shall not prohibit reverse
 
                                        4
<PAGE>   
 
repurchase agreements, deposits of assets to margin or guarantee positions in
futures, options, swaps or forward contracts, or the segregation of assets in
connection with such contracts.
 
     (f) The Fund does not currently intend to purchase any security or enter
into a repurchase agreement if, as a result, more than 15% of its net assets
would be invested in repurchase agreements not entitling the holder to payment
of principal and interest within seven days and in securities that are illiquid
by virtue of legal or contractual restrictions on resale or the absence of a
readily available market. The Trustees, or the Fund's investment adviser acting
pursuant to authority delegated by the Trustees, may determine that a readily
available market exists for securities eligible for resale pursuant to Rule 144A
under the Securities Act of 1933 ("Rule 144A Securities"), or any successor to
such rule, Section 4(2) commercial paper and municipal lease obligations.
Accordingly, such securities may not be subject to the foregoing limitation.
 
     (g) The Fund may not invest in companies for the purpose of exercising
control of management.
 
   
     Under the terms of an exemptive order received from the Securities and
Exchange Commission ("SEC") the Fund may borrow money from or lend money to
other funds that permit such transactions and for which Janus Capital serves as
investment adviser. All such borrowing and lending will be subject to the above
limits.  The Fund will borrow money through the program only when the costs
are equal to or lower than the cost of bank loans.  Interfund loans and 
borrowings normally extend overnight, but can have a maximum duration of seven
days.  The Fund will lend through the program only when the returns are higher
than those available from other short-term instruments (such as repurchase
agreements).  The Fund may have to borrow from a bank at a higher interest rate
if an interfund loan is called or not renewed.  Any delay in repayment to a 
lending Fund could result in a lost investment opportunity or additional 
borrowing costs.
      
    
 
   
     For purposes of the Fund's restriction on investing in a particular
industry, the Fund will rely primarily on industry classifications as published
by Bloomberg L.P. To the extent that Bloomberg L.P. classifications are so broad
that the primary economic characteristics in a single class are materially
different, the Fund may further classify issuers in accordance with industry
classifications as published by the SEC.
    
 
                            TYPES OF SECURITIES AND
                             INVESTMENT TECHNIQUES
 
ILLIQUID INVESTMENTS
   
     The Fund may invest up to 15% of its net assets in illiquid investments
(i.e., securities that are not readily marketable). The Trustees have authorized
Janus Capital to make liquidity determinations with respect to certain
securities, including Rule 144A Securities, commercial paper and municipal lease
obligations purchased by the Fund. Under the guidelines established by the
Trustees, Janus Capital will consider the following factors: 1) the frequency of
trades and quoted prices for the obligation; 2) the number of dealers willing to
purchase or sell the security and the number of other potential purchasers; 3)
the willingness of dealers to undertake to make a market in the security; and 4)
the nature of the security and the nature of marketplace trades, including the
time needed to dispose of the security, the method of soliciting offers and the
mechanics of the transfer. In the case of commercial paper, Janus Capital will
also consider whether the paper is traded flat or in default as to principal and
interest and any ratings of the paper by a Nationally Recognized Statistical
Rating Organization ("NRSRO"). A foreign security that may be freely traded on
or through the facilities of
    
 
                                        5
<PAGE>   
 
an offshore exchange or other established offshore securities market is not
deemed to be a restricted security subject to these procedures.
 
ZERO COUPON, PAY-IN-KIND AND STEP COUPON SECURITIES
     The Fund may invest up to 10% of its assets in zero coupon, pay-in-kind and
step coupon securities. Zero coupon bonds are issued and traded at a discount
from their face value. They do not entitle the holder to any periodic payment of
interest prior to maturity. Step coupon bonds trade at a discount from their
face value and pay coupon interest. The coupon rate is low for an initial period
and then increases to a higher coupon rate thereafter. The discount from the
face amount or par value depends on the time remaining until cash payments
begin, prevailing interest rates, liquidity of the security and the perceived
credit quality of the issuer. Pay-in-kind bonds normally give the issuer an
option to pay cash at a coupon payment date or give the holder of the security a
similar bond with the same coupon rate and a face value equal to the amount of
the coupon payment that would have been made.
 
     Current federal income tax law requires holders of zero coupon securities
and step coupon securities to report the portion of the original issue discount
on such securities that accrues during a given year as interest income, even
though the holders receive no cash payments of interest during the year. In
order to qualify as a "regulated investment company" under the Internal Revenue
Code of 1986 and the regulations thereunder (the "Code"), the Fund must
distribute its investment company taxable income, including the original issue
discount accrued on zero coupon or step coupon bonds. Because the Fund will not
receive cash payments on a current basis in respect of accrued original issue
discount on zero coupon bonds or step coupon bonds during the period before
interest payments begin, in some years the Fund may have to distribute cash
obtained from other sources in order to satisfy the distribution requirements
under the Code. The Fund might obtain such cash from selling other portfolio
holdings which might cause the Fund to incur capital gains or losses on the
sale. Additionally, these actions are likely to reduce the assets to which Fund
expenses could be allocated and to reduce the rate of return for the Fund. In
some circumstances, such sales might be necessary in order to satisfy cash
distribution requirements even though investment considerations might otherwise
make it undesirable for the Fund to sell the securities at the time.
 
     Generally, the market prices of zero coupon, step coupon and pay-in-kind
securities are more volatile than the prices of securities that pay interest
periodically and in cash and are likely to respond to changes in interest rates
to a greater degree than other types of debt securities having similar
maturities and credit quality.
 
PASS-THROUGH SECURITIES
     The Fund may invest in various types of pass-through securities, such as
mortgage-backed securities, asset-backed securities and participation interests.
A pass-through security is a share or certificate of interest in a pool of debt
obligations that have been repackaged by an intermediary, such as a bank or
broker-dealer. The purchaser of a pass-through security receives an undivided
interest in the underlying pool of securities. The issuers of the underlying
securities make interest and principal payments to the intermediary which are
passed through to purchasers, such as the Fund. The most common type of
pass-through securities are mortgage-backed securities. Government
 
                                        6
<PAGE>   
 
National Mortgage Association ("GNMA") Certificates are mortgage-backed
securities that evidence an undivided interest in a pool of mortgage loans. GNMA
Certificates differ from bonds in that principal is paid back monthly by the
borrowers over the term of the loan rather than returned in a lump sum at
maturity. The Fund will generally purchase "modified pass-through" GNMA
Certificates, which entitle the holder to receive a share of all interest and
principal payments paid and owned on the mortgage pool, net of fees paid to the
"issuer" and GNMA, regardless of whether or not the mortgagor actually makes the
payment. GNMA Certificates are backed as to the timely payment of principal and
interest by the full faith and credit of the U.S. government.
 
     The Federal Home Loan Mortgage Corporation ("FHLMC") issues two types of
mortgage pass-through securities: mortgage participation certificates ("PCs")
and guaranteed mortgage certificates ("GMCs"). PCs resemble GNMA Certificates in
that each PC represents a pro rata share of all interest and principal payments
made and owned on the underlying pool. FHLMC guarantees timely payments of
interest on PCs and the full return of principal. GMCs also represent a pro rata
interest in a pool of mortgages. However, these instruments pay interest
semiannually and return principal once a year in guaranteed minimum payments.
This type of security is guaranteed by FHLMC as to timely payment of principal
and interest but it is not guaranteed by the full faith and credit of the U.S.
government.
 
     The Federal National Mortgage Association ("FNMA") issues guaranteed
mortgage pass-through certificates ("FNMA Certificates"). FNMA Certificates
resemble GNMA Certificates in that each FNMA Certificate represents a pro rata
share of all interest and principal payments made and owned on the underlying
pool. This type of security is guaranteed by FNMA as to timely payment of
principal and interest but it is not guaranteed by the full faith and credit of
the U.S. government.
 
     Except for GMCs, each of the mortgage-backed securities described above is
characterized by monthly payments to the holder, reflecting the monthly payments
made by the borrowers who received the underlying mortgage loans. The payments
to the security holders (such as the Fund), like the payments on the underlying
loans, represent both principal and interest. Although the underlying mortgage
loans are for specified periods of time, such as 20 or 30 years, the borrowers
can, and typically do, pay them off sooner. Thus, the security holders
frequently receive prepayments of principal in addition to the principal that is
part of the regular monthly payments. The Fund's portfolio managers will
consider estimated prepayment rates in calculating the average weighted maturity
of the Fund. A borrower is more likely to prepay a mortgage that bears a
relatively high rate of interest. This means that in times of declining interest
rates, higher yielding mortgage-backed securities held by the Fund might be
converted to cash and the Fund will be forced to accept lower interest rates
when that cash is used to purchase additional securities in the mortgage-backed
securities sector or in other investment sectors. Additionally, prepayments
during such periods will limit the Fund's ability to participate in as large a
market gain as may be experienced with a comparable security not subject to
prepayment.
 
     Asset-backed securities represent interests in pools of consumer loans and
are backed by paper or accounts receivables originated by banks, credit card
companies or other providers of credit. Generally, the originating bank or
credit provider is neither the obligor or guarantor of the security and interest
and principal payments ultimately
 
                                        7
<PAGE>   
 
depend upon payment of the underlying loans by individuals. Tax-exempt
asset-backed securities include units of beneficial interests in pools of
purchase contracts, financing leases, and sales agreements that may be created
when a municipality enters into an installment purchase contract or lease with a
vendor. Such securities may be secured by the assets purchased or leased by the
municipality; however, if the municipality stops making payments, there
generally will be no recourse against the vendor. The market for tax-exempt
asset-backed securities is still relatively new. These obligations are likely to
involve unscheduled prepayments of principal.
 
INVESTMENT COMPANY SECURITIES
   
     From time to time, the Fund may invest in securities of other investment
companies, subject to the provisions of Section 12(d)(1) of the 1940 Act. The
Fund may invest in securities of money market funds managed by Janus Capital
subject to the terms of an exemptive order obtained by Janus Capital and the
Janus funds which currently provides that the Fund will limit its aggregate
investment in a Janus money market fund to the greater of (i) 5% of its total
assets or (ii) $2.5 million. The Janus funds are seeking an amended and restated
exemptive order that would permit the Fund to invest in Janus money market funds
in excess of the limitations of Section 12(d)(1) of the 1940 Act. There is no
assurance that such amendment will be granted.
    
 
DEPOSITARY RECEIPTS
     The Fund may invest in sponsored and unsponsored American Depositary
Receipts ("ADRs"), which are receipts issued by an American bank or trust
company evidencing ownership of underlying securities issued by a foreign
issuer. ADRs, in registered form, are designed for use in U.S. securities
markets. Unsponsored ADRs may be created without the participation of the
foreign issuer. Holders of these ADRs generally bear all the costs of the ADR
facility, whereas foreign issuers typically bear certain costs in a sponsored
ADR. The bank or trust company depositary of an unsponsored ADR may be under no
obligation to distribute shareholder communications received from the foreign
issuer or to pass through voting rights. The Fund may also invest in European
Depositary Receipts ("EDRs"), Global Depositary Receipts ("GDRs") and in other
similar instruments representing securities of foreign companies. EDRs are
receipts issued by a European financial institution evidencing an arrangement
similar to that of ADRs. EDRs, in bearer form, are designed for use in European
securities markets.
 
MUNICIPAL OBLIGATIONS
     The Fund may invest in municipal obligations issued by states, territories
and possessions of the United States and the District of Columbia. The value of
municipal obligations can be affected by changes in their actual or perceived
credit quality. The credit quality of municipal obligations can be affected by,
among other things, the financial condition of the issuer or guarantor, the
issuer's future borrowing plans and sources of revenue, the economic feasibility
of the revenue bond project or general borrowing purpose, political or economic
developments in the region where the security is issued, and the liquidity of
the security. Because municipal securities are generally traded
over-the-counter, the liquidity of a particular issue often depends on the
willingness of dealers to make a market in the security. The liquidity of some
municipal
 
                                        8
<PAGE>   
 
obligations may be enhanced by demand features, which would enable the Fund to
demand payment on short notice from the issuer or a financial intermediary.
 
OTHER INCOME-PRODUCING SECURITIES
     Other types of income producing securities that the Fund may purchase
include, but are not limited to, the following types of securities:
 
     VARIABLE AND FLOATING RATE OBLIGATIONS. These types of securities have
variable or floating rates of interest and, under certain limited circumstances,
may have varying principal amounts. Variable and floating rate securities pay
interest at rates that are adjusted periodically according to a specified
formula, usually with reference to some interest rate index or market interest
rate (the "underlying index"). See also "Inverse Floaters."
 
     STANDBY COMMITMENTS. These instruments, which are similar to a put, give
the Fund the option to obligate a broker, dealer or bank to repurchase a
security held by the Fund at a specified price.
 
     TENDER OPTION BONDS. Tender option bonds are generally long-term securities
that are coupled with the option to tender the securities to a bank,
broker-dealer or other financial institution at periodic intervals and receive
the face value of the bond. This type of security is commonly used as a means of
enhancing the security's liquidity.
 
     INVERSE FLOATERS. Inverse floaters are debt instruments whose interest
bears an inverse relationship to the interest rate on another security. Certain
inverse floaters may have an interest rate reset mechanism that multiplies the
effects of change in the underlying index. Such mechanism may increase the
volatility of the security's market value. Certain variable rate securities
(including certain mortgage-backed securities) pay interest at a rate that
varies inversely to prevailing short-term interest rates (sometimes referred to
as inverse floaters). For example, upon reset the interest rate payable on a
security may go down when the underlying index has risen. The Fund will not
invest more than 5% of its assets in inverse floaters.
 
     The Fund will purchase standby commitments, tender option bonds and
instruments with demand features primarily for the purpose of increasing the
liquidity of its portfolio.
 
HIGH-YIELD/HIGH-RISK SECURITIES
     The Fund intends to invest less than 35% of its net assets in debt
securities that are rated below investment grade (e.g., securities rated BB or
lower by Standard & Poor's Ratings Services ("Standard & Poor's") or Ba or lower
by Moody's Investors Service, Inc. ("Moody's")). Lower rated securities involve
a higher degree of credit risk, which is the risk that the issuer will not make
interest or principal payments when due. In the event of an unanticipated
default, the Fund would experience a reduction in its income, and could expect a
decline in the market value of the securities so affected.
 
     The Fund may also invest in unrated debt securities of foreign and domestic
issuers. Unrated debt, while not necessarily of lower quality than rated
securities, may not have as broad a market. Sovereign debt of foreign
governments is generally rated by country. Because these ratings do not take
into account individual factors relevant to
 
                                        9
<PAGE>   
 
each issue and may not be updated regularly, Janus Capital may treat such
securities as unrated debt. Because of the size and perceived demand of the
issue, among other factors, certain municipalities may not incur the costs of
obtaining a rating. The Fund's portfolio managers will analyze the
creditworthiness of the issuer, as well as any financial institution or other
party responsible for payments on the security, in determining whether to
purchase unrated municipal bonds. Unrated debt securities will be included in
the 35% limit unless the portfolio managers deem such securities to be the
equivalent of investment grade securities.
 
     Subject to the above limits, the Fund may purchase defaulted securities
only when its portfolio managers believe, based upon their analysis of the
financial condition, results of operations and economic outlook of an issuer,
that there is potential for resumption of income payments and that the
securities offer an unusual opportunity for capital appreciation.
Notwithstanding the portfolio managers' belief as to the resumption of income,
however, the purchase of any security on which payment of interest or dividends
is suspended involves a high degree of risk. Such risk includes, among other
things, the following:
 
     Financial and Market Risks. Investments in securities that are in default
involve a high degree of financial and market risks that can result in
substantial or, at times, even total losses. Issuers of defaulted securities may
have substantial capital needs and may become involved in bankruptcy or
reorganization proceedings. Among the problems involved in investments in such
issuers is the fact that it may be difficult to obtain information about the
condition of such issuers. The market prices of such securities also are subject
to abrupt and erratic movements and above average price volatility, and the
spread between the bid and asked prices of such securities may be greater than
normally expected.
 
     Disposition of Portfolio Securities. Although the Fund generally will
purchase securities for which its portfolio managers expect an active market to
be maintained, defaulted securities may be less actively traded than other
securities and it may be difficult to dispose of substantial holdings of such
securities at prevailing market prices. The Fund will limit holdings of any such
securities to amounts that the portfolio managers believe could be readily sold,
and holdings of such securities would, in any event, be limited so as not to
limit the Fund's ability to readily dispose of securities to meet redemptions.
 
     Other. Defaulted securities require active monitoring and may, at times,
require participation in bankruptcy or receivership proceedings on behalf of the
Fund.
 
REPURCHASE AND REVERSE REPURCHASE AGREEMENTS
     In a repurchase agreement, the Fund purchases a security and simultaneously
commits to resell that security to the seller at an agreed upon price on an
agreed upon date within a number of days (usually not more than seven) from the
date of purchase. The resale price reflects the purchase price plus an agreed
upon incremental amount that is unrelated to the coupon rate or maturity of the
purchased security. A repurchase agreement involves the obligation of the seller
to pay the agreed upon price, which obligation is in effect secured by the value
(at least equal to the amount of the agreed upon resale price and
marked-to-market daily) of the underlying security or "collateral." The Fund may
engage in a repurchase agreement with respect to any
 
                                       10
<PAGE>   
 
security in which it is authorized to invest. A risk associated with repurchase
agreements is the failure of the seller to repurchase the securities as agreed,
which may cause the Fund to suffer a loss if the market value of such securities
declines before they can be liquidated on the open market. In the event of
bankruptcy or insolvency of the seller, the Fund may encounter delays and incur
costs in liquidating the underlying security. Repurchase agreements that mature
in more than seven days will be subject to the 15% limit on illiquid
investments. While it is possible to eliminate all risks from these
transactions, it is the policy of the Fund to limit repurchase agreements to
those parties whose creditworthiness has been reviewed and found satisfactory by
Janus Capital.
 
     The Fund may use reverse repurchase agreements to provide cash to satisfy
unusually heavy redemption requests or for other temporary or emergency purposes
without the necessity of selling portfolio securities or to earn additional
income on portfolio securities, such as Treasury bills or notes. In a reverse
repurchase agreement, the Fund sells a portfolio security to another party, such
as a bank or broker-dealer, in return for cash and agrees to repurchase the
instrument at a particular price and time. While a reverse repurchase agreement
is outstanding, the Fund will maintain cash and appropriate liquid assets in a
segregated custodial account to cover its obligation under the agreement. The
Fund will enter into reverse repurchase agreements only with parties that Janus
Capital deems creditworthy. Using reverse repurchase agreements to earn
additional income involves the risk that the interest earned on the invested
proceeds is less than the expense of the reverse repurchase agreement
transaction. This technique may also have a leveraging effect on the Fund's
portfolio, although the Fund's intent to segregate assets in the amount of the
reverse repurchase agreement minimizes this effect.
 
FUTURES, OPTIONS AND OTHER DERIVATIVE INSTRUMENTS
     FUTURES CONTRACTS. The Fund may enter into contracts for the purchase or
sale for future delivery of fixed-income securities, foreign currencies or
contracts based on financial indices, including indices of U.S. government
securities, foreign government securities, equity or fixed-income securities.
U.S. futures contracts are traded on exchanges which have been designated
"contract markets" by the CFTC and must be executed through a futures commission
merchant ("FCM"), or brokerage firm, which is a member of the relevant contract
market. Through their clearing corporations, the exchanges guarantee performance
of the contracts as between the clearing members of the exchange.
 
     The buyer or seller of a futures contract is not required to deliver or pay
for the underlying instrument unless the contract is held until the delivery
date. However, both the buyer and seller are required to deposit "initial
margin" for the benefit of the FCM when the contract is entered into. Initial
margin deposits are equal to a percentage of the contract's value, as set by the
exchange on which the contract is traded, and may be maintained in cash or
certain other liquid assets by the Fund's custodian for the benefit of the FCM.
Initial margin payments are similar to good faith deposits or performance bonds.
Unlike margin extended by a securities broker, initial margin payments do not
constitute purchasing securities on margin for purposes of the Fund's investment
limitations. If the value of either party's position declines, that party will
be required to make additional "variation margin" payments for the benefit of
the FCM to settle the
 
                                       11
<PAGE>   
 
change in value on a daily basis. The party that has a gain may be entitled to
receive all or a portion of this amount. In the event of the bankruptcy of the
FCM that holds margin on behalf of the Fund, the Fund may be entitled to a
return of margin owed to the Fund only in proportion to the amount received by
the FCM's other customers. Janus Capital will attempt to minimize the risk by
careful monitoring of the creditworthiness of the FCMs with which the Fund does
business and by depositing margin payments in a segregated account with the
Fund's custodian.
 
     The Fund intends to comply with guidelines of eligibility for exclusion
from the definition of the term "commodity pool operator" adopted by the CFTC
and the National Futures Association, which regulate trading in the futures
markets. The Fund will use futures contracts and related options primarily for
bona fide hedging purposes within the meaning of CFTC regulations. To the extent
that the Fund holds positions in futures contracts and related options that do
not fall within the definition of bona fide hedging transactions, the aggregate
initial margin and premiums required to establish such positions will not exceed
5% of the fair market value of the Fund's net assets, after taking into account
unrealized profits and unrealized losses on any such contracts it has entered
into.
 
     Although the Fund will segregate cash and liquid assets in an amount
sufficient to cover its open futures obligations, the segregated assets would be
available to the Fund immediately upon closing out the futures position, while
settlement of securities transactions could take several days. However, because
the Fund's cash that may otherwise be invested would be held uninvested or
invested in other liquid assets so long as the futures position remains open,
the Fund's return could be diminished due to the opportunity losses of foregoing
other potential investments.
 
     The Fund's primary purpose in entering into futures contracts is to protect
the Fund from fluctuations in the value of securities or interest rates without
actually buying or selling the underlying debt or equity security. For example,
if the Fund anticipates an increase in the price of stocks, and it intends to
purchase stocks at a later time, the Fund could enter into a futures contract to
purchase a stock index as a temporary substitute for stock purchases. If an
increase in the market occurs that influences the stock index as anticipated,
the value of the futures contracts will increase, thereby serving as a hedge
against the Fund not participating in a market advance. This technique is
sometimes known as an anticipatory hedge. To the extent the Fund enters into
futures contracts for this purpose, the segregated assets maintained to cover
the Fund's obligations with respect to the futures contracts will consist of
other liquid assets from its portfolio in an amount equal to the difference
between the contract price and the aggregate value of the initial and variation
margin payments made by the Fund with respect to the futures contracts.
Conversely, if the Fund holds stocks and seeks to protect itself from a decrease
in stock prices, the Fund might sell stock index futures contracts, thereby
hoping to offset the potential decline in the value of its portfolio securities
by a corresponding increase in the value of the futures contract position. The
Fund could protect against a decline in stock prices by selling portfolio
securities and investing in money market instruments, but the use of futures
contracts enables it to maintain a defensive position without having to sell
portfolio securities.
 
     If the Fund owns Treasury bonds and the portfolio managers expect interest
rates to increase, the Fund may take a short position in interest rate futures
contracts. Taking
 
                                       12
<PAGE>   
 
such a position would have much the same effect as the Fund selling Treasury
bonds in its portfolio. If interest rates increase as anticipated, the value of
the Treasury bonds would decline, but the value of the Fund's interest rate
futures contract will increase, thereby keeping the net asset value of the Fund
from declining as much as it may have otherwise. If, on the other hand, the
portfolio managers expect interest rates to decline, the Fund may take a long
position in interest rate futures contracts in anticipation of later closing out
the futures position and purchasing bonds. Although the Fund can accomplish
similar results by buying securities with long maturities and selling securities
with short maturities, given the greater liquidity of the futures market than
the cash market, it may be possible to accomplish the same result more easily
and more quickly by using futures contracts as an investment tool to reduce
risk.
 
     The ordinary spreads between prices in the cash and futures markets, due to
differences in the nature of those markets, are subject to distortions. First,
all participants in the futures market are subject to initial margin and
variation margin requirements. Rather than meeting additional variation margin
requirements, investors may close out futures contracts through offsetting
transactions which could distort the normal price relationship between the cash
and futures markets. Second, the liquidity of the futures market depends on
participants entering into offsetting transactions rather than making or taking
delivery of the instrument underlying a futures contract. To the extent
participants decide to make or take delivery, liquidity in the futures market
could be reduced and prices in the futures market distorted. Third, from the
point of view of speculators, the margin deposit requirements in the futures
market are less onerous than margin requirements in the securities market.
Therefore, increased participation by speculators in the futures market may
cause temporary price distortions. Due to the possibility of the foregoing
distortions, a correct forecast of general price trends by the portfolio
managers still may not result in a successful use of futures.
 
     Futures contracts entail risks. Although the Fund believes that use of such
contracts will benefit the Fund, the Fund's overall performance could be worse
than if the Fund had not entered into futures contracts if the portfolio
managers' investment judgement proves incorrect. For example, if the Fund has
hedged against the effects of a possible decrease in prices of securities held
in its portfolio and prices increase instead, the Fund will lose part or all of
the benefit of the increased value of these securities because of offsetting
losses in its futures positions. In addition, if the Fund has insufficient cash,
it may have to sell securities from its portfolio to meet daily variation margin
requirements. Those sales may be, but will not necessarily be, at increased
prices which reflect the rising market and may occur at a time when the sales
are disadvantageous to the Fund.
 
     The prices of futures contracts depend primarily on the value of their
underlying instruments. Because there are a limited number of types of futures
contracts, it is possible that the standardized futures contracts available to
the Fund will not match exactly the Fund's current or potential investments. The
Fund may buy and sell futures contracts based on underlying instruments with
different characteristics from the securities in which it typically invests D
for example, by hedging investments in portfolio securities with a futures
contract based on a broad index of securities D which involves a risk that the
futures position will not correlate precisely with the performance of the Fund's
investments.
 
                                       13
<PAGE>   
 
     Futures prices can also diverge from the prices of their underlying
instruments, even if the underlying instruments closely correlate with the
Fund's investments. Futures prices are affected by factors such as current and
anticipated short-term interest rates, changes in volatility of the underlying
instruments and the time remaining until expiration of the contract. Those
factors may affect securities prices differently from futures prices. Imperfect
correlations between the Fund's investments and its futures positions also may
result from differing levels of demand in the futures markets and the securities
markets, from structural differences in how futures and securities are traded,
and from imposition of daily price fluctuation limits for futures contracts. The
Fund may buy or sell futures contracts with a greater or lesser value than the
securities it wishes to hedge or is considering purchasing in order to attempt
to compensate for differences in historical volatility between the futures
contract and the securities, although this may not be successful in all cases.
If price changes in the Fund's futures positions are poorly correlated with its
other investments, its futures positions may fail to produce desired gains or
result in losses that are not offset by the gains in the Fund's other
investments.
 
     Because futures contracts are generally settled within a day from the date
they are closed out, compared with a settlement period of three days for some
types of securities, the futures markets can provide superior liquidity to the
securities markets. Nevertheless, there is no assurance that a liquid secondary
market will exist for any particular futures contract at any particular time. In
addition, futures exchanges may establish daily price fluctuation limits for
futures contracts and may halt trading if a contract's price moves upward or
downward more than the limit in a given day. On volatile trading days when the
price fluctuation limit is reached, it may be impossible for the Fund to enter
into new positions or close out existing positions. If the secondary market for
a futures contract is not liquid because of price fluctuation limits or
otherwise, the Fund may not be able to promptly liquidate unfavorable futures
positions and potentially could be required to continue to hold a futures
position until the delivery date, regardless of changes in its value. As a
result, the Fund's access to other assets held to cover its futures positions
also could be impaired.
 
     OPTIONS ON FUTURES CONTRACTS. The Fund may buy and write put and call
options on futures contracts. An option on a future gives the Fund the right
(but not the obligation) to buy or sell a futures contract at a specified price
on or before a specified date. The purchase of a call option on a futures
contract is similar in some respects to the purchase of a call option on an
individual security. Depending on the pricing of the option compared to either
the price of the futures contract upon which it is based or the price of the
underlying instrument, ownership of the option may or may not be less risky than
ownership of the futures contract or the underlying instrument. As with the
purchase of futures contracts, when the Fund is not fully invested it may buy a
call option on a futures contract to hedge against a market advance.
 
     The writing of a call option on a futures contract constitutes a partial
hedge against declining prices of the security or foreign currency which is
deliverable under, or of the index comprising, the futures contract. If the
future's price at the expiration of the option is below the exercise price, the
Fund will retain the full amount of the option premium which provides a partial
hedge against any decline that may have occurred in the Fund's portfolio
holdings. The writing of a put option on a futures contract constitutes a
partial hedge against increasing prices of the security or foreign
 
                                       14
<PAGE>   
 
currency which is deliverable under, or of the index comprising, the futures
contract. If the futures' price at expiration of the option is higher than the
exercise price, the Fund will retain the full amount of the option premium which
provides a partial hedge against any increase in the price of securities which
the Fund is considering buying. If a call or put option the Fund has written is
exercised, the Fund will incur a loss which will be reduced by the amount of the
premium it received. Depending on the degree of correlation between the change
in the value of its portfolio securities and changes in the value of the futures
positions, the Fund's losses from existing options on futures may to some extent
be reduced or increased by changes in the value of portfolio securities.
 
     The purchase of a put option on a futures contract is similar in some
respects to the purchase of protective put options on portfolio securities. For
example, the Fund may buy a put option on a futures contract to hedge its
portfolio against the risk of falling prices or rising interest rates.
 
     The amount of risk the Fund assumes when it buys an option on a futures
contract is the premium paid for the option plus related transaction costs. In
addition to the correlation risks discussed above, the purchase of an option
also entails the risk that changes in the value of the underlying futures
contract will not be fully reflected in the value of the options bought.
 
     FORWARD CONTRACTS. A forward contract is an agreement between two parties
in which one party is obligated to deliver a stated amount of a stated asset at
a specified time in the future and the other party is obligated to pay a
specified amount for the assets at the time of delivery. The Fund may enter into
forward contracts to purchase and sell government securities, equity or income
securities, foreign currencies or other financial instruments. Forward contracts
generally are traded in an interbank market conducted directly between traders
(usually large commercial banks) and their customers. Unlike futures contracts,
which are standardized contracts, forward contracts can be specifically drawn to
meet the needs of the parties that enter into them. The parties to a forward
contract may agree to offset or terminate the contract before its maturity, or
may hold the contract to maturity and complete the contemplated exchange.
 
     The following discussion summarizes the Fund's principal uses of forward
foreign currency exchange contracts ("forward currency contracts"). The Fund may
enter into forward currency contracts with stated contract values of up to the
value of the Fund's assets. A forward currency contract is an obligation to buy
or sell an amount of a specified currency for an agreed price (which may be in
U.S. dollars or a foreign currency). The Fund will exchange foreign currencies
for U.S. dollars and for other foreign currencies in the normal course of
business and may buy and sell currencies through forward currency contracts in
order to fix a price for securities it has agreed to buy or sell ("transaction
hedge"). The Fund also may hedge some or all of its investments denominated in a
foreign currency or exposed to foreign currency fluctuations against a decline
in the value of that currency relative to the U.S. dollar by entering into
forward currency contracts to sell an amount of that currency (or a proxy
currency whose performance is expected to replicate or exceed the performance of
that currency relative to the U.S. dollar) approximating the value of some or
all of its portfolio securities denominated in that currency ("position hedge")
or by participating in options or futures contracts with respect to the
currency. The Fund also may enter
 
                                       15
<PAGE>   
 
into a forward currency contract with respect to a currency where the Fund is
considering the purchase or sale of investments denominated in that currency but
has not yet selected the specific investments ("anticipatory hedge"). In any of
these circumstances the Fund may, alternatively, enter into a forward currency
contract to purchase or sell one foreign currency for a second currency that is
expected to perform more favorably relative to the U.S. dollar if the portfolio
managers believe there is a reasonable degree of correlation between movements
in the two currencies ("cross-hedge").
 
     These types of hedging minimize the effect of currency appreciation as well
as depreciation, but do not eliminate fluctuations in the underlying U.S. dollar
equivalent value of the proceeds of or rates of return on the Fund's foreign
currency denominated portfolio securities. The matching of the increase in value
of a forward contract and the decline in the U.S. dollar equivalent value of the
foreign currency denominated asset that is the subject of the hedge generally
will not be precise. Shifting the Fund's currency exposure from one foreign
currency to another removes the Fund's opportunity to profit from increases in
the value of the original currency and involves a risk of increased losses to
the Fund if its portfolio managers' projection of future exchange rates is
inaccurate. Proxy hedges and cross-hedges may result in losses if the currency
used to hedge does not perform similarly to the currency in which hedged
securities are denominated. Unforeseen changes in currency prices may result in
poorer overall performance for the Fund than if it had not entered into such
contracts.
 
     The Fund will cover outstanding forward currency contracts by maintaining
liquid portfolio securities denominated in or whose value its tied to, the
currency underlying the forward contract or the currency being hedged. To the
extent that the Fund is not able to cover its forward currency positions with
underlying portfolio securities, the Fund's custodian will segregate cash or
other liquid assets having a value equal to the aggregate amount of the Fund's
commitments under forward contracts entered into with respect to position
hedges, cross-hedges and anticipatory hedges. If the value of the securities
used to cover a position or the value of segregated assets declines, the Fund
will find alternative cover or segregate additional cash or liquid assets on a
daily basis so that the value of the covered and segregated assets will be equal
to the amount of the Fund's commitments with respect to such contracts. As an
alternative to segregating assets, the Fund may buy call options permitting the
Fund to buy the amount of foreign currency being hedged by a forward sale
contract or the Fund may buy put options permitting it to sell the amount of
foreign currency subject to a forward buy contract.
 
     While forward contracts are not currently regulated by the CFTC, the CFTC
may in the future assert authority to regulate forward contacts. In such event,
the Fund's ability to utilize forward contracts may be restricted. In addition,
the Fund may not always be able to enter into forward contracts at attractive
prices and may be limited in its ability to use these contracts to hedge Fund
assets.
 
     OPTIONS ON FOREIGN CURRENCIES. The Fund may buy and write options on
foreign currencies in a manner similar to that in which futures or forward
contracts on foreign currencies will be utilized. For example, a decline in the
U.S. dollar value of a foreign currency in which portfolio securities are
denominated will reduce the U.S. dollar value of such securities, even if their
value in the foreign currency remains constant. In order to protect against such
diminutions in the value of portfolio
 
                                       16
<PAGE>   
 
securities, the Fund may buy put options on the foreign currency. If the value
of the currency declines, the Fund will have the right to sell such currency for
a fixed amount in U.S. dollars, thereby offsetting, in whole or in part, the
adverse effect on its portfolio.
 
   
     Conversely, when a rise in the U.S. dollar value of a currency in which
securities to be acquired are denominated is projected, thereby increasing the
cost of such securities, the Fund may buy call options on the foreign currency.
The purchase of such options could offset, at least partially, the effects of
the adverse movements in exchange rates. As in the case of other types of
options, however, the benefit to the Fund from purchases of foreign currency
options will be reduced by the amount of the premium and related transaction
costs. In addition, if currency exchange rates do not move in the direction or
to the extent projected, the Fund could sustain losses on transactions in
foreign currency options that would require the Fund to forego a portion or all
of the benefits of advantageous changes in those rates.
    
 
     The Fund may also write options on foreign currencies. For example, to
hedge against a potential decline in the U.S. dollar value of foreign currency
denominated securities due to adverse fluctuations in exchange rates, the Fund
could, instead of purchasing a put option, write a call option on the relevant
currency. If the expected decline occurs, the option will most likely not be
exercised and the decline in value of portfolio securities will be offset by the
amount of the premium received.
 
   
     Similarly, instead of purchasing a call option to hedge against a potential
increase in the U.S. dollar cost of securities to be acquired, the Fund could
write a put option on the relevant currency which, if rates move in the manner
projected, should expire unexercised and allow the Fund to hedge the increased
cost up to the amount of the premium. As in the case of other types of options,
however, the writing of a foreign currency option will constitute only a partial
hedge up to the amount of the premium. If exchange rates do not move in the
expected direction, the option may be exercised and the Fund would be required
to buy or sell the underlying currency at a loss which may not be offset by the
amount of the premium. Through the writing of options on foreign currencies, the
Fund also may lose all or a portion of the benefits which might otherwise have
been obtained from favorable movements in exchange rates.
    
 
     The Fund may write covered call options on foreign currencies. A call
option written on a foreign currency by the Fund is "covered" if the Fund owns
the foreign currency underlying the call or has an absolute and immediate right
to acquire that foreign currency without additional cash consideration (or for
additional cash consideration held in a segregated account by its custodian)
upon conversion or exchange of other foreign currencies held in its portfolio. A
call option is also covered if the Fund has a call on the same foreign currency
in the same principal amount as the call written if the exercise price of the
call held (i) is equal to or less than the exercise price of the call written or
(ii) is greater than the exercise price of the call written, if the difference
is maintained by the Fund in cash or other liquid assets in a segregated account
with the Fund's custodian.
 
     The Fund also may write call options on foreign currencies for
cross-hedging purposes. A call option on a foreign currency is for cross-hedging
purposes if it is designed to provide a hedge against a decline due to an
adverse change in the exchange
 
                                       17
<PAGE>   
 
rate in the U.S. dollar value of a security which the Fund owns or has the right
to acquire and which is denominated in the currency underlying the option. Call
options on foreign currencies which are entered into for cross-hedging purposes
are not covered. However, in such circumstances, the Fund will collateralize the
option by segregating cash or other liquid assets in an amount not less than the
value of the underlying foreign currency in U.S. dollars marked-to-market daily.
 
     OPTIONS ON SECURITIES. In an effort to increase current income and to
reduce fluctuations in net asset value, the Fund may write covered put and call
options and buy put and call options on securities that are traded on United
States and foreign securities exchanges and over-the-counter. The Fund may write
and buy options on the same types of securities that the Fund may purchase
directly.
 
     A put option written by the Fund is "covered" if the Fund (i) segregates
cash not available for investment or other liquid assets with a value equal to
the exercise price of the put with the Fund's custodian or (ii) holds a put on
the same security and in the same principal amount as the put written and the
exercise price of the put held is equal to or greater than the exercise price of
the put written. The premium paid by the buyer of an option will reflect, among
other things, the relationship of the exercise price to the market price and the
volatility of the underlying security, the remaining term of the option, supply
and demand and interest rates.
 
     A call option written by the Fund is "covered" if the Fund owns the
underlying security covered by the call or has an absolute and immediate right
to acquire that security without additional cash consideration (or for
additional cash consideration held in a segregated account by the Fund's
custodian) upon conversion or exchange of other securities held in its
portfolio. A call option is also deemed to be covered if the Fund holds a call
on the same security and in the same principal amount as the call written and
the exercise price of the call held (i) is equal to or less than the exercise
price of the call written or (ii) is greater than the exercise price of the call
written if the difference is maintained by the Fund in cash and other liquid
assets in a segregated account with its custodian.
 
     The Fund also may write call options that are not covered for cross-hedging
purposes. The Fund collateralizes its obligation under a written call option for
cross-hedging purposes by segregating cash or other liquid assets in an amount
not less than the market value of the underlying security, marked-to-market
daily. The Fund would write a call option for cross-hedging purposes, instead of
writing a covered call option, when the premium to be received from the
cross-hedge transaction would exceed that which would be received from writing a
covered call option and its portfolio managers believe that writing the option
would achieve the desired hedge.
 
     The writer of an option may have no control over when the underlying
securities must be sold, in the case of a call option, or bought, in the case of
a put option, since with regard to certain options, the writer may be assigned
an exercise notice at any time prior to the termination of the obligation.
Whether or not an option expires unexercised, the writer retains the amount of
the premium. This amount, of course, may, in the case of a covered call option,
be offset by a decline in the market value of the underlying security during the
option period. If a call option is exercised, the writer experiences a profit or
loss from the sale of the underlying security. If a put option is
 
                                       18
<PAGE>   
 
exercised, the writer must fulfill the obligation to buy the underlying security
at the exercise price, which will usually exceed the then market value of the
underlying security.
 
     The writer of an option that wishes to terminate its obligation may effect
a "closing purchase transaction." This is accomplished by buying an option of
the same series as the option previously written. The effect of the purchase is
that the writer's position will be canceled by the clearing corporation.
However, a writer may not effect a closing purchase transaction after being
notified of the exercise of an option. Likewise, an investor who is the holder
of an option may liquidate its position by effecting a "closing sale
transaction." This is accomplished by selling an option of the same series as
the option previously bought. There is no guarantee that either a closing
purchase or a closing sale transaction can be effected.
 
     In the case of a written call option, effecting a closing transaction will
permit the Fund to write another call option on the underlying security with
either a different exercise price or expiration date or both. In the case of a
written put option, such transaction will permit the Fund to write another put
option to the extent that the exercise price is secured by other liquid assets.
Effecting a closing transaction also will permit the Fund to use the cash or
proceeds from the concurrent sale of any securities subject to the option for
other investments. If the Fund desires to sell a particular security from its
portfolio on which it has written a call option, the Fund will effect a closing
transaction prior to or concurrent with the sale of the security.
 
     The Fund will realize a profit from a closing transaction if the price of
the purchase transaction is less than the premium received from writing the
option or the price received from a sale transaction is more than the premium
paid to buy the option. The Fund will realize a loss from a closing transaction
if the price of the purchase transaction is more than the premium received from
writing the option or the price received from a sale transaction is less than
the premium paid to buy the option. Because increases in the market of a call
option generally will reflect increases in the market price of the underlying
security, any loss resulting from the repurchase of a call option is likely to
be offset in whole or in part by appreciation of the underlying security owned
by the Fund.
 
     An option position may be closed out only where a secondary market for an
option of the same series exists. If a secondary market does not exist, the Fund
may not be able to effect closing transactions in particular options and the
Fund would have to exercise the options in order to realize any profit. If the
Fund is unable to effect a closing purchase transaction in a secondary market,
it will not be able to sell the underlying security until the option expires or
it delivers the underlying security upon exercise. The absence of a liquid
secondary market may be due to the following: (i) insufficient trading interest
in certain options, (ii) restrictions imposed by a national securities exchange
("Exchange") on which the option is traded on opening or closing transactions or
both, (iii) trading halts, suspensions or other restrictions imposed with
respect to particular classes or series of options or underlying securities,
(iv) unusual or unforeseen circumstances that interrupt normal operations on an
Exchange, (v) the facilities of an Exchange or of the Options Clearing
Corporation ("OCC") may not at all times be adequate to handle current trading
volume, or (vi) one or more Exchanges could, for economic or other reasons,
decide or be compelled at some future date to
 
                                       19
<PAGE>   
 
discontinue the trading of options (or a particular class or series of options),
in which event the secondary market on that Exchange (or in that class or series
of options) would cease to exist, although outstanding options on that Exchange
that had been issued by the OCC as a result of trades on that Exchange would
continue to be exercisable in accordance with their terms.
 
     The Fund may write options in connection with buy-and-write transactions.
In other words, the Fund may buy a security and then write a call option against
that security. The exercise price of such call will depend upon the expected
price movement of the underlying security. The exercise price of a call option
may be below ("in-the-money"), equal to ("at-the-money") or above
("out-of-the-money") the current value of the underlying security at the time
the option is written. Buy-and-write transactions using in-the-money call
options may be used when it is expected that the price of the underlying
security will remain flat or decline moderately during the option period.
Buy-and-write transactions using at-the-money call options may be used when it
is expected that the price of the underlying security will remain fixed or
advance moderately during the option period. Buy-and-write transactions using
out-of-the-money call options may be used when it is expected that the premiums
received from writing the call option plus the appreciation in the market price
of the underlying security up to the exercise price will be greater than the
appreciation in the price of the underlying security alone. If the call options
are exercised in such transactions, the Fund's maximum gain will be the premium
received by it for writing the option, adjusted upwards or downwards by the
difference between the Fund's purchase price of the security and the exercise
price. If the options are not exercised and the price of the underlying security
declines, the amount of such decline will be offset by the amount of premium
received.
 
     The writing of covered put options is similar in terms of risk and return
characteristics to buy-and-write transactions. If the market price of the
underlying security rises or otherwise is above the exercise price, the put
option will expire worthless and the Fund's gain will be limited to the premium
received. If the market price of the underlying security declines or otherwise
is below the exercise price, the Fund may elect to close the position or take
delivery of the security at the exercise price and the Fund's return will be the
premium received from the put options minus the amount by which the market price
of the security is below the exercise price.
 
     The Fund may buy put options to hedge against a decline in the value of its
portfolio. By using put options in this way, the Fund will reduce any profit it
might otherwise have realized in the underlying security by the amount of the
premium paid for the put option and by transaction costs.
 
     The Fund may buy call options to hedge against an increase in the price of
securities that it may buy in the future. The premium paid for the call option
plus any transaction costs will reduce the benefit, if any, realized by the Fund
upon exercise of the option, and, unless the price of the underlying security
rises sufficiently, the option may expire worthless to the Fund.
 
     EURODOLLAR INSTRUMENTS. The Fund may make investments in Eurodollar
instruments. Eurodollar instruments are U.S. dollar-denominated futures
contracts or options thereon which are linked to the London Interbank Offered
Rate ("LIBOR"),
 
                                       20
<PAGE>   
 
although foreign currency-denominated instruments are available from time to
time. Eurodollar futures contracts enable purchasers to obtain a fixed rate for
the lending of funds and sellers to obtain a fixed rate for borrowings. The Fund
might use Eurodollar futures contracts and options thereon to hedge against
changes in LIBOR, to which many interest rate swaps and fixed-income instruments
are linked.
 
     SWAPS AND SWAP-RELATED PRODUCTS. The Fund may enter into interest rate
swaps, caps and floors on either an asset-based or liability-based basis,
depending upon whether it is hedging its assets or its liabilities, and will
usually enter into interest rate swaps on a net basis (i.e., the two payment
streams are netted out, with the Fund receiving or paying, as the case may be,
only the net amount of the two payments). The net amount of the excess, if any,
of the Fund's obligations over its entitlement with respect to each interest
rate swap will be calculated on a daily basis and an amount of cash or other
liquid assets having an aggregate net asset value at least equal to the accrued
excess will be maintained in a segregated account by the Fund's custodian. If
the Fund enters into an interest rate swap on other than a net basis, it would
maintain a segregated account in the full amount accrued on a daily basis of its
obligations with respect to the swap. The Fund will not enter into any interest
rate swap, cap or floor transaction unless the unsecured senior debt or the
claims-paying ability of the other party thereto is rated in one of the three
highest rating categories of at least one NRSRO at the time of entering into
such transaction. Janus Capital will monitor the creditworthiness of all
counterparties on an ongoing basis. If there is a default by the other party to
such a transaction, the Fund will have contractual remedies pursuant to the
agreements related to the transaction.
 
     The swap market has grown substantially in recent years with a large number
of banks and investment banking firms acting both as principals and as agents
utilizing standardized swap documentation. Janus Capital has determined that, as
a result, the swap market has become relatively liquid. Caps and floors are more
recent innovations for which standardized documentation has not yet been
developed and, accordingly, they are less liquid than swaps. To the extent the
Fund sells (i.e., writes) caps and floors, it will segregate cash or other
liquid assets having an aggregate net asset value at least equal to the full
amount, accrued on a daily basis, of its obligations with respect to any caps or
floors.
 
     There is no limit on the amount of interest rate swap transactions that may
be entered into by the Fund. These transactions may in some instances involve
the delivery of securities or other underlying assets by the Fund or its
counterparty to collateralize obligations under the swap. Under the
documentation currently used in those markets, the risk of loss with respect to
interest rate swaps is limited to the net amount of the payments that the Fund
is contractually obligated to make. If the other party to an interest rate swap
that is not collateralized defaults, the Fund would risk the loss of the net
amount of the payments that it contractually is entitled to receive. The Fund
may buy and sell (i.e., write) caps and floors without limitation, subject to
the segregation requirement described above.
 
     ADDITIONAL RISKS OF OPTIONS ON FOREIGN CURRENCIES, FORWARD CONTRACTS AND
FOREIGN INSTRUMENTS. Unlike transactions entered into by the Fund in futures
contracts, options on foreign currencies and forward contracts are not traded on
contract markets regulated by the CFTC or (with the exception of certain foreign
 
                                       21
<PAGE>   
 
currency options) by the SEC. To the contrary, such instruments are traded
through financial institutions acting as market-makers, although foreign
currency options are also traded on certain Exchanges, such as the Philadelphia
Stock Exchange and the Chicago Board Options Exchange, subject to SEC
regulation. Similarly, options on currencies may be traded over the-counter. In
an over-the-counter trading environment, many of the protections afforded to
Exchange participants will not be available. For example, there are no daily
price fluctuation limits, and adverse market movements could therefore continue
to an unlimited extent over a period of time. Although the buyer of an option
cannot lose more than the amount of the premium plus related transaction costs,
this entire amount could be lost. Moreover, an option writer and a buyer or
seller of futures or forward contracts could lose amounts substantially in
excess of any premium received or initial margin or collateral posted due to the
potential additional margin and collateral requirements associated with such
positions.
 
     Options on foreign currencies traded on Exchanges are within the
jurisdiction of the SEC, as are other securities traded on Exchanges. As a
result, many of the protections provided to traders on organized Exchanges will
be available with respect to such transactions. In particular, all foreign
currency option positions entered into on an Exchange are cleared and guaranteed
by the OCC, thereby reducing the risk of counterparty default. Further, a liquid
secondary market in options traded on an Exchange may be more readily available
than in the over-the-counter market, potentially permitting the Fund to
liquidate open positions at a profit prior to exercise or expiration, or to
limit losses in the event of adverse market movements.
 
     The purchase and sale of exchange-traded foreign currency options, however,
is subject to the risks of the availability of a liquid secondary market
described above, as well as the risks regarding adverse market movements,
margining of options written, the nature of the foreign currency market,
possible intervention by governmental authorities and the effects of other
political and economic events. In addition, exchange-traded options on foreign
currencies involve certain risks not presented by the over-the-counter market.
For example, exercise and settlement of such options must be made exclusively
through the OCC, which has established banking relationships in applicable
foreign countries for this purpose. As a result, the OCC may, if it determines
that foreign governmental restrictions or taxes would prevent the orderly
settlement of foreign currency option exercises, or would result in undue
burdens on the OCC or its clearing member, impose special procedures on exercise
and settlement, such as technical changes in the mechanics of delivery of
currency, the fixing of dollar settlement prices or prohibitions on exercise.
 
     In addition, options on U.S. government securities, futures contracts,
options on futures contracts, forward contracts and options on foreign
currencies may be traded on foreign exchanges and over-the-counter in foreign
countries. Such transactions are subject to the risk of governmental actions
affecting trading in or the prices of foreign currencies or securities. The
value of such positions also could be adversely affected by (i) other complex
foreign political and economic factors, (ii) lesser availability than in the
United States of data on which to make trading decisions, (iii) delays in the
Fund's ability to act upon economic events occurring in foreign markets during
non-business hours in the United States, (iv) the imposition of different
exercise and settlement terms
 
                                       22
<PAGE>   
 
and procedures and margin requirements than in the United States, and (v) low
trading volume.
 
                               INVESTMENT ADVISER
 
     As stated in the Prospectus, the Fund has an Investment Advisory Agreement
with Janus Capital, 100 Fillmore Street, Denver, Colorado 80206-4928. The
Advisory Agreement provides that Janus Capital will furnish continuous advice
and recommendations concerning the Fund's investments, provide office space for
the Fund, and pay the salaries, fees and expenses of all Fund officers and of
those Trustees who are affiliated with Janus Capital. Janus Capital also may
make payments to selected broker-dealer firms or institutions which perform
recordkeeping or other services with respect to shareholder accounts. The
minimum aggregate size required for eligibility for such payments, and the
factors in selecting the broker-dealer firms and institutions to which they will
be made, are determined from time to time by Janus Capital. Janus Capital is
also authorized to perform the management and administrative services necessary
for the operation of the Fund.
 
     The Fund pays custodian and transfer agent fees and expenses, brokerage
commissions and dealer spreads and other expenses in connection with the
execution of portfolio transactions, legal and accounting expenses, interest and
taxes, registration fees, expenses of shareholders' meetings and reports to
shareholders, fees and expenses of Trustees who are not affiliated with Janus
Capital, costs of preparing, printing and mailing the Fund's Prospectus and SAI
to current shareholders, and other costs of complying with applicable laws
regulating the sale of Fund shares. Pursuant to the Advisory Agreement, Janus
Capital furnishes certain other services, including net asset value
determination and Fund accounting, recordkeeping, and blue sky registration and
monitoring services, for which the Fund may reimburse Janus Capital for its
costs.
 
   
     The Fund has agreed to compensate Janus Capital for its services by the
monthly payment of a fee at the annual rate of 0.75% of the first $300 million
of the Fund's average daily net assets, 0.70% of the next $200 million of the
Fund's average daily net assets, and 0.65% of the average daily net assets of
the Fund in excess of $500 million.
    
 
   
     [TO BE FILED BY AMENDMENT] For the fiscal year ended October 31, 1997, the
investment advisory fee was $          . For the fiscal years ended October 31,
1996 and October 31, 1995, the Fund incurred investment advisory fees of
$12,316,252 and $10,947,796, respectively. Janus Capital did not waive any
portion of its fee in any of these years.
    
 
   
     The Advisory Agreement is dated July 1, 1997, and it will continue in
effect until July 1, 1998, and thereafter from year to year so long as such
continuance is approved annually by a majority of the Fund's Trustees who are
not parties to the Advisory Agreement or interested persons of any such party,
and by either a majority of the outstanding voting shares or the Trustees of the
Fund. The Advisory Agreement i) may be terminated without the payment of any
penalty by the Fund or Janus Capital on 60 days' written notice; ii) terminates
automatically in the event of its assignment; and iii) generally, may not be
amended without the approval by vote of a majority of the Trustees of the Fund,
including the Trustees who are not interested persons of the Fund
    
 
                                       23
<PAGE>   
 
or Janus Capital and, to the extent required by the 1940 Act, the vote of a
majority of the outstanding voting securities of the Fund.
 
     Janus Capital also performs investment advisory services for other mutual
funds, and for individual, charitable, corporate and retirement accounts.
Investment decisions for each account managed by Janus Capital, including the
Fund, are made independently from those for any other account that is or may in
the future become managed by Janus Capital or its affiliates. If, however, a
number of accounts managed by Janus Capital are contemporaneously engaged in the
purchase or sale of the same security, the orders may be aggregated and/or the
transactions may be averaged as to price and allocated equitably to each
account. In some cases, this policy might adversely affect the price paid or
received by an account or the size of the position obtained or liquidated for an
account. Pursuant to an exemptive order granted by the SEC, the Fund and other
funds advised by Janus Capital may also transfer daily uninvested cash balances
into one or more joint trading accounts. Assets in the joint trading accounts
are invested in money market instruments and the proceeds are allocated to the
participating Funds on a pro rata basis.
 
     Each account managed by Janus Capital has its own investment objective and
policies and is managed accordingly by a particular portfolio manager or team of
portfolio managers. As a result, from time to time two or more different managed
accounts may pursue divergent investment strategies with respect to investments
or categories of investments.
 
   
     As indicated in the Prospectus, Janus Capital does not permit the Fund's
portfolio managers to purchase and sell securities for their own accounts except
under the limited exceptions contained in Janus Capital's policy regarding
personal investing by directors/Trustees, officers and employees of Janus
Capital and the Trust. The policy requires investment personnel and officers of
Janus Capital, inside directors/Trustees of Janus Capital and the Fund and other
designated persons deemed to have access to current trading information to
pre-clear all transactions in securities not otherwise exempt under the policy.
Requests for trading authority will be denied when, among other reasons, the
proposed personal transaction would be contrary to the provisions of the policy
or would be deemed to adversely affect any transaction known to be under
consideration for or to have been effected on behalf of any client account,
including the Fund.
    
 
   
     In addition to the pre-clearance requirement described above, the policy
subjects investment personnel, officers and directors/Trustees of Janus Capital
and the Trust to various trading restrictions and reporting obligations. All
reportable transactions are reviewed for compliance with Janus Capital's policy.
Those persons also may be required under certain circumstances to forfeit their
profits made from personal trading.
    
 
     The provisions of the policy are administered by and subject to exceptions
authorized by Janus Capital.
 
     Kansas City Southern Industries, Inc., a publicly traded holding company
whose primary subsidiaries are engaged in transportation, information processing
and financial services ("KCSI"), owns approximately 83% of Janus Capital. Thomas
H. Bailey, the President and Chairman of the Board of Janus Capital, owns
approximately 12% of its voting stock and, by agreement with KCSI, selects a
majority of Janus Capital's Board.
 
                                       24
<PAGE>   
 
                           CUSTODIAN, TRANSFER AGENT
                            AND CERTAIN AFFILIATIONS
 
     State Street Bank and Trust Company ("State Street"), P.O. Box 0351,
Boston, Massachusetts 02117-0351 is the custodian of the domestic securities and
cash of the Fund. State Street and the foreign subcustodians selected by it and
approved by the Trustees, have custody of the assets of the Fund held outside
the U.S. and cash incidental thereto. The custodian and subcustodians hold the
Fund's assets in safekeeping and collect and remit the income thereon, subject
to the instructions of the Fund.
 
   
     Janus Service Corporation ("Janus Service"), P.O. Box 173375, Denver,
Colorado 80217-3375, a wholly-owned subsidiary of Janus Capital, is the Fund's
transfer agent. In addition, Janus Service provides certain other
administrative, recordkeeping and shareholder relations services to the Fund.
For transfer agency and other services, Janus Service receives a fee calculated
at an annual rate of 0.16% of average net assets of the Fund. In addition, the
Fund pays DST Systems, Inc. ("DST"), a subsidiary of KCSI, license fees at the
rate of $3.06 per shareholder account for the use of DST's shareholder
accounting system. The fund also pays DST $1.10 per closed shareholder account.
The Fund pays DST for the use of its portfolio and fund accounting system a
monthly base fee of $250 to $1,250 based on the number of Janus funds using the
system and an asset charge of $1 per million dollars of net assets (not to
exceed $500 per month). In addition, the Fund pays DST postage and forms costs
of a DST affiliate incurred in mailing Fund shareholder transaction
confirmations.
    
 
   
     The Trustees have authorized the Fund to use another affiliate of DST as
introducing broker for certain Fund portfolio transactions as a means to reduce
Fund expenses through credits against the charges of DST and its affiliates with
regard to commissions earned by such affiliate. See "Portfolio Transactions and
Brokerage."
    
 
     Janus Distributors, Inc. ("Janus Distributors"), 100 Fillmore Street,
Denver, Colorado 80206-4928, a wholly-owned subsidiary of Janus Capital, is a
distributor of the Fund. Janus Distributors is registered as a broker-dealer
under the Securities Exchange Act of 1934 (the "Exchange Act") and is a member
of the National Association of Securities Dealers, Inc. Janus Distributors acts
as the agent of the Fund in connection with the sale of its shares in all states
in which the shares are registered and in which Janus Distributors is qualified
as a broker-dealer. Under the Distribution Agreement, Janus Distributors
continuously offers the Fund's shares and accepts orders at net asset value. No
sales charges are paid by investors. Promotional expenses in connection with
offers and sales of shares are paid by Janus Capital.
 
                             PORTFOLIO TRANSACTIONS
                                 AND BROKERAGE
 
     Decisions as to the assignment of portfolio business for the Fund and
negotiation of its commission rates are made by Janus Capital whose policy is to
obtain the "best execution" (prompt and reliable execution at the most favorable
security price) of all portfolio transactions. The Fund may trade foreign
securities in foreign countries because
 
                                       25
<PAGE>   
 
the best available market for these securities is often on foreign exchanges. In
transactions on foreign stock exchanges, brokers' commissions are frequently
fixed and are often higher than in the United States, where commissions are
negotiated.
 
     In selecting brokers and dealers and in negotiating commissions, Janus
Capital considers a number of factors, including but not limited to: Janus
Capital's knowledge of currently available negotiated commission rates or prices
of securities currently available and other current transaction costs; the
nature of the security being traded; the size and type of the transaction; the
nature and character of the markets for the security to be purchased or sold;
the desired timing of the trade; the activity existing and expected in the
market for the particular security; confidentiality; the quality of the
execution, clearance and settlement services; financial stability of the broker
or dealer; the existence of actual or apparent operational problems of any
broker or dealer; rebates of commissions by a broker to the Fund or to a third
party service provider to the Fund to pay Fund expenses; and research products
or services provided. In recognition of the value of the foregoing factors,
Janus Capital may place portfolio transactions with a broker or dealer with whom
it has negotiated a commission that is in excess of the commission another
broker or dealer would have charged for effecting that transaction if Janus
Capital determines in good faith that such amount of commission was reasonable
in relation to the value of the brokerage and research provided by such broker
or dealer viewed in terms of either that particular transaction or of the
overall responsibilities of Janus Capital. Research may include furnishing
advice, either directly or through publications or writings, as to the value of
securities, the advisability of purchasing or selling specific securities and
the availability of securities or purchasers or sellers of securities;
furnishing seminars, information, analyses and reports concerning issuers,
industries, securities, trading markets and methods, legislative developments,
changes in accounting practices, economic factors and trends and portfolio
strategy; access to research analysts, corporate management personnel, industry
experts, economists and government officials; comparative performance evaluation
and technical measurement services and quotation services, and products and
other services (such as third party publications, reports and analyses, and
computer and electronic access, equipment, software, information and accessories
that deliver, process or otherwise utilize information, including the research
described above) that assist Janus Capital in carrying out its responsibilities.
 
   
     Most brokers and dealers used by Janus Capital provide research and other
services described above. [TO BE FILED BY AMENDMENT] For the year ended October
31, 1997, the Fund paid $          of its total brokerage commissions to brokers
and dealers in transactions identified for execution primarily on the basis of
research and other services provided to the Fund on transactions of
$               . Research received from brokers or dealers is supplemental to
Janus Capital's own research efforts.
    
 
     Janus Capital may use research products and services in servicing other
accounts in addition to the Fund. If Janus Capital determines that any research
product or service has a mixed use, such that it also serves functions that do
not assist in the investment decision-making process, Janus Capital may allocate
the costs of such service or product accordingly. Only that portion of the
product or service that Janus Capital determines will assist it in the
investment decision-making process may be paid for in brokerage commission
dollars. Such allocation may create a conflict of interest for Janus Capital.
 
                                       26
<PAGE>   
 
     Janus Capital does not enter into agreements with any brokers regarding the
placement of securities transactions because of the research services they
provide. It does, however, have an internal procedure for allocating
transactions in a manner consistent with its execution policy to brokers that it
has identified as providing superior executions and research, research-related
products or services which benefit its advisory clients, including the Fund.
Research products and services incidental to effecting securities transactions
furnished by brokers or dealers may be used in servicing any or all of Janus
Capital's clients and such research may not necessarily be used by Janus Capital
in connection with the accounts which paid commissions to the broker-dealer
providing such research products and services.
 
     Janus Capital may consider sales of Fund shares by a broker-dealer or the
recommendation of a broker-dealer to its customers that they purchase Fund
shares as a factor in the selection of broker-dealers to execute Fund portfolio
transactions. Janus Capital may also consider payments made by brokers effecting
transactions for the Fund i) to the Fund or ii) to other persons on behalf of
the Fund for services provided to the Fund for which it would be obligated to
pay. In placing portfolio business with such broker-dealers, Janus Capital will
seek the best execution of each transaction.
 
     When the Fund purchases or sells a security in the over-the-counter market,
the transaction takes place directly with a principal market-maker, without the
use of a broker, except in those circumstances where in the opinion of Janus
Capital better prices and executions will be achieved through the use of a
broker.
 
     The Fund's Trustees have authorized Janus Capital to place transactions
with DST Securities, Inc. ("DSTS"), a wholly-owned broker-dealer subsidiary of
DST. Janus Capital may do so if it reasonably believes that the quality of the
transaction and the associated commission are fair and reasonable and if,
overall, the associated transaction costs, net of any credits described above
under "Custodian, Transfer Agent and Certain Affiliations," are lower than those
that would otherwise be incurred.
 
   
     The total amount of brokerage commissions paid by the Fund during the
fiscal year ended October 31, 1997, was $          . For the fiscal years ended
October 31, 1996 and October 31, 1995, the Fund paid brokerage commissions of
$3,945,142 and $3,920,258, respectively. Included in the brokerage commissions
paid for the fiscal year ended October 31, 1997, was $          paid through
DSTS, which served to reduce by $          certain out-of-pocket expenses paid
by the Fund. Included in brokerage commissions paid for the fiscal years ended
October 31, 1996 and October 31, 1995, was $64,665 and $143,719, respectively,
paid through DSTS which served to reduce by $48,499 and $107,789, respectively,
certain out-of-pocket expenses. Brokerage commissions paid through DSTS for the
1997 fiscal year represented   % of the Fund's aggregate brokerage commissions
for such fiscal year, while   % of the aggregate dollar amount of the Fund's
portfolio transactions involving a commission payment were executed through
DSTS. The difference between commissions paid through DSTS and expenses reduced
constitute commissions paid to an unaffiliated clearing broker. Differences in
the percentage of total commissions versus the percentage of total transactions
is due, in part, to variations among share prices and number of shares traded,
while average price per share commission rates were substantially the same.
    
 
                                       27
<PAGE>   
 
                             OFFICERS AND TRUSTEES
 
     The following are the names of the Trustees and officers of the Trust,
together with a brief description of their principal occupations during the last
five years. In August 1992, Janus Venture Fund, Inc. and Janus Twenty Fund, Inc.
(both separate Maryland corporations) and the Janus Income Series (a
Massachusetts business trust comprised of Janus Flexible Income Fund series)
were reorganized into separate series of the Trust. In general, all references
to Trust offices in this section include comparable offices with the respective
predecessor funds, unless a Trust office was filled subsequent to the
reorganization.
 
Thomas H. Bailey*# - Trustee, Chairman and President
100 Fillmore Street
Denver, CO 80206-4928
     Trustee, Chairman and President of Janus Aspen Series. Chairman, Chief
     Executive Officer, Director and President of Janus Capital. Chairman and
     Director of IDEX Management, Inc., Largo, Florida (50% subsidiary of Janus
     Capital and investment adviser to a group of mutual funds) ("IDEX").
 
James P. Craig, III*# - Trustee and Executive Vice President
100 Fillmore Street
Denver, CO 80206-4928
   
     Trustee and Executive Vice President of Janus Aspen Series. Chief
     Investment Officer, Vice President and Director of Janus Capital. Executive
     Vice President and Portfolio Manager of Janus Fund. Executive Vice
     President and Co-Manager of Janus Venture Fund.
    
 
   
William H. Bales* - Executive Vice President
100 Fillmore Street
Denver, CO 80206-4928
    
   
     Executive Vice President and Portfolio Manager of Janus Venture Fund.
     Formerly, research analyst at Janus Capital (1993-1996).
    
 
Jonathan D. Coleman* - Executive Vice President
100 Fillmore Street
Denver, CO 80206-4928
     Executive Vice President and Portfolio Manager of Janus Venture Fund.
     Formerly, research analyst at Janus Capital (1994-1996). Fulbright Fellow
     (1993-1994). Obtained a Bachelor of Arts in Political Economy and Spanish
     from Williams College (1991-1993).
 
- --------------------------------------------------------------------------------
*Interested person of the Trust and of Janus Capital.
#Member of the Trust's Executive Committee.
 
                                       28
<PAGE>   
 
   
Steven R. Goodbarn* - Vice President and Chief Financial Officer
100 Fillmore Street
Denver, CO 80206-4928
    
   
     Vice President and Chief Financial Officer of Janus Aspen Series. Vice
     President of Finance, Treasurer and Chief Financial Officer of Janus
     Service, Janus Distributors and Janus Capital. Director of IDEX, Janus
     Service and Janus Distributors. Director, Treasurer and Vice President of
     Finance of Janus Capital International Ltd. Formerly (May 1992-January
     1996), Treasurer of Janus Investment Fund and Janus Aspen Series.
    
 
Glenn P. O'Flaherty* - Treasurer and Chief Accounting Officer
100 Fillmore Street
Denver, CO 80206-4928
     Treasurer and Chief Accounting Officer of Janus Aspen Series. Director of
     Fund Accounting of Janus Capital.
 
Kelley Abbott Howes* - Secretary
100 Fillmore Street
Denver, CO 80206-4928
   
     Secretary of Janus Aspen Series. Director and President of Janus
     Distributors. Associate Counsel of Janus Capital. Formerly (1990 to 1994),
     with The Boston Company Advisors, Inc., Boston, Massachusetts (mutual fund
     administration services).
    
 
   
William D. Stewart# - Trustee
5330 Sterling Drive
Boulder, CO 80302
    
   
     Trustee of Janus Aspen Series. President of HPS Division of MKS
     Instruments, Boulder, Colorado (manufacturer of vacuum fittings and
     valves).
    
 
   
Gary O. Loo# - Trustee
102 N. Cascade, Suite 500
Colorado Springs, CO 80903
    
     Trustee of Janus Aspen Series. President and a Director of High Valley
     Group, Inc., Colorado Springs, Colorado (investments).
 
   
Dennis B. Mullen - Trustee
14103 Denver West Parkway
Golden, CO 80401
    
   
     Trustee of Janus Aspen Series. Chief Financial Officer - Boston Market
     Concepts, Boston Chicken, Inc., Golden, Colorado (restaurant chain).
     Formerly (1993 to 1997), President and Chief Executive Officer of BC
     Northwest, L.P., a franchise of Boston Chicken, Inc., Bellevue, Washington
     (restaurant chain).
    
 
- --------------------------------------------------------------------------------
   
*Interested person of the Trust and of Janus Capital.
    
   
#Member of the Trust's Executive Committee.
    
 
                                       29
<PAGE>   
 
Martin H. Waldinger - Trustee
4940 Sandshore Court
San Diego, CA 92130
   
     Trustee of Janus Aspen Series. Private Consultant. Formerly (1993 to 1996),
     Director of Run Technologies, Inc., a software development firm, San
     Carlos, California. Formerly (1989 to 1993), President and Chief Executive
     Officer of Bridgecliff Management Services, Campbell, California (a
     condominium association management company).
    
 
James T. Rothe - Trustee
102 South Tejon Street, Suite 1100
Colorado Springs, CO 80903
     Trustee of Janus Aspen Series. Professor of Business, University of
     Colorado, Colorado Springs, Colorado. Principal, Phillips-Smith Retail
     Group, Colorado Springs, Colorado (a venture capital firm). Formerly
     (1986-1994), Dean of the College of Business, University of Colorado,
     Colorado Springs, Colorado.
 
     The Trustees are responsible for major decisions relating to the Fund's
objective, policies and techniques. The Trustees also supervise the operation of
the Fund by its officers and review the investment decisions of the officers
although they do not actively participate on a regular basis in making such
decisions.
 
   
     The Trust's Executive Committee shall have and may exercise all the powers
and authority of the Trustees except for matters requiring action by all
Trustees pursuant to the Trust's Bylaws or Agreement and Declaration of Trust
("Declaration of Trust"), Massachusetts law or the 1940 Act.
    
 
   
     The following table shows the aggregate compensation earned by and paid to
each Trustee by the Fund described in this SAI and all funds advised and
sponsored by Janus Capital (collectively, the "Janus Funds") for the periods
indicated. None of the Trustees receive any pension or retirement benefits from
the Fund or the Janus Funds.
    
 
   
<TABLE>
<CAPTION>
                           Aggregate Compensation      Total Compensation
                             from the Funds for     from the Janus Funds for
                             fiscal year ended         calendar year ended
                              October 31, 1997         December 31, 1997**
                              [To be filed by            [To be filed by
Name of Person, Position         Amendment]                Amendment]
- -----------------------------------------------------------------------------
<S>                        <C>                      <C>
Thomas H. Bailey,
  Chairman*                      $                         $
James P. Craig, III,
  Trustee*                       $                         $
William D. Stewart,
  Trustee                        $                         $
Gary O. Loo, Trustee             $                         $
Dennis B. Mullen, Trustee        $                         $
Martin H. Waldinger,
  Trustee                        $                         $
James T. Rothe, Trustee          $                         $
- -----------------------------------------------------------------------------
</TABLE>
    
 
 *An interested person of the Fund and of Janus Capital. Compensated by Janus
Capital and not the Fund.
   
**As of December 31, 1997, Janus Funds consisted of two registered investment
  companies comprised of a total of 32 funds.
    
 
                                       30
<PAGE>   
 
   
                               PURCHASE OF SHARES
    
 
     The Fund has discontinued public sales of its shares to new investors. Only
shareholders who maintain open accounts are permitted to continue to make
investments in the Fund and to reinvest any dividends and capital gains
distributions. Once a Fund account is closed, additional investments in the Fund
may not be possible. The Shareholder's Manual section of the Prospectus contains
detailed information about the purchase of shares.
 
NET ASSET VALUE DETERMINATION
   
     As stated in the Prospectus, the net asset value ("NAV") of Fund shares is
determined once each day on which the New York Stock Exchange ("NYSE") is open,
at the close of its regular trading session (normally 4:00 p.m., New York time,
Monday through Friday). The NAV of Fund shares is not determined on days the
NYSE is closed (generally, New Year's Day, Presidents' Day, Martin Luther King
Day, Good Friday, Memorial Day, Independence Day, Labor Day, Thanksgiving and
Christmas). The per share NAV of the Fund is determined by dividing the total
value of the Fund's securities and other assets, less liabilities, by the total
number of shares outstanding. In determining NAV, securities listed on an
Exchange, the NASDAQ National Market and foreign markets are valued at the
closing prices on such markets, or if such price is lacking for the trading
period immediately preceding the time of determination, such securities are
valued at their current bid price. Municipal securities held by the Fund are
traded primarily in the over-the-counter market. Valuations of such securities
are furnished by one or more pricing services employed by the Fund and are based
upon a computerized matrix system or appraisals obtained by a pricing service,
in each case in reliance upon information concerning market transactions and
quotations from recognized municipal securities dealers. Other securities that
are traded on the over-the-counter market are valued at their closing bid
prices. Foreign securities and currencies are converted to U.S. dollars using
the exchange rate in effect at the close of the NYSE. The Fund will determine
the market value of individual securities held by it, by using prices provided
by one or more professional pricing services which may provide market prices to
other funds, or, as needed, by obtaining market quotations from independent
broker-dealers. Short-term securities maturing within 60 days are valued on an
amortized cost basis. Securities for which quotations are not readily available,
and other assets, are valued at fair values determined in good faith under
procedures established by and under the supervision of the Trustees.
    
 
     Trading in securities on European and Far Eastern securities exchanges and
over-the-counter markets is normally completed well before the close of business
on each business day in New York (i.e., a day on which the NYSE is open). In
addition, European or Far Eastern securities trading generally or in a
particular country or countries may not take place on all business days in New
York. Furthermore, trading takes place in Japanese markets on certain Saturdays
and in various foreign markets on days which are not business days in New York
and on which the Fund's NAV is not calculated. The Fund calculates its NAV per
share, and therefore effects sales, redemptions and repurchases of its shares,
as of the close of the NYSE once on each day on which the NYSE is open. Such
calculation may not take place contemporaneously
 
                                       31
<PAGE>   
 
with the determination of the prices of the foreign portfolio securities used in
such calculation.
 
REINVESTMENT OF DIVIDENDS AND DISTRIBUTIONS
   
     If investors do not elect in writing or by phone to receive their dividends
and distributions in cash, all income dividends and capital gains distributions,
if any, on the Fund's shares are reinvested automatically in additional shares
of the Fund at the NAV determined on the first business day following the record
date. Checks for cash dividends and distributions and confirmations of
reinvestments are usually mailed to shareholders within ten days after the
record date. Any election of the manner in which a shareholder wishes to receive
dividends and distributions (which may be made on the New Account Application
form or by phone) will apply to dividends and distributions the record dates of
which fall on or after the date that the Fund receives such notice. Changes to
distribution options must be received at least three days prior to the record
date to be effective for such date. Investors receiving cash distributions and
dividends may elect in writing or by phone to change back to automatic
reinvestment at any time.
    
 
                              REDEMPTION OF SHARES
 
     Procedures for redemption of shares are set forth in the Shareholder's
Manual section of the Prospectus. Shares normally will be redeemed for cash,
although the Fund retains the right to redeem its shares in kind under unusual
circumstances, in order to protect the interests of remaining shareholders, by
delivery of securities selected from its assets at its discretion. However, the
Fund is governed by Rule 18f-1 under the 1940 Act, which requires the Fund to
redeem shares solely in cash up to the lesser of $250,000 or 1% of the NAV of
the Fund during any 90-day period for any one shareholder. Should redemptions by
any shareholder exceed such limitation, the Fund will have the option of
redeeming the excess in cash or in kind. If shares are redeemed in kind, the
redeeming shareholder might incur brokerage costs in converting the assets to
cash. The method of valuing securities used to make redemptions in kind will be
the same as the method of valuing portfolio securities described under "Purchase
of Shares D Net Asset Value Determination" and such valuation will be made as of
the same time the redemption price is determined.
 
     The right to require the Fund to redeem its shares may be suspended, or the
date of payment may be postponed, whenever (1) trading on the NYSE is
restricted, as determined by the SEC, or the NYSE is closed except for holidays
and weekends, (2) the SEC permits such suspension and so orders, or (3) an
emergency exists as determined by the SEC so that disposal of securities or
determination of NAV is not reasonably practicable.
 
                              SHAREHOLDER ACCOUNTS
 
     Detailed information about the general procedures for shareholder accounts
and specific types of accounts is set forth in the Prospectus. Applications for
specific types of accounts may be obtained by calling the Fund at 1-800-525-3713
or writing to the Fund at P.O. Box 173375, Denver, Colorado 80217-3375.
 
                                       32
<PAGE>   
 
TELEPHONE TRANSACTIONS
     As stated in the Prospectus, shareholders may initiate a number of
transactions by telephone. The Fund, its transfer agent and its distributor
disclaim responsibility for the authenticity of instructions received by
telephone. Such entities will employ reasonable procedures to confirm that
instructions communicated by telephone are genuine. Such procedures may include,
among others, requiring personal identification prior to acting upon telephone
instructions, providing written confirmation of the transactions and tape
recording telephone conversations.
 
SYSTEMATIC REDEMPTIONS
   
     As stated in the Shareholder's Manual section of the Prospectus, if you
have a regular account or are eligible for distributions from a retirement plan,
you may establish a systematic redemption option. The payments will be made from
the proceeds of periodic redemptions of shares in the account at the NAV.
Depending on the size or frequency of the disbursements requested, and the
fluctuation in value of the Fund's portfolio, redemptions for the purpose of
making such disbursements may reduce or even exhaust the shareholder's account.
Either an investor or the Fund, by written notice to the other, may terminate
the investor's systematic redemption option without penalty at any time.
    
 
     Information about requirements to establish a systematic redemption option
may be obtained by writing or calling the Fund at the address or phone number
shown above.
 
   
                             TAX-DEFERRED ACCOUNTS
    
 
   
     The Fund offers several different types of tax-deferred accounts that an
investor may establish to invest in Fund shares, depending on rules prescribed
by the Code. Regular and Roth Individual Retirement Accounts ("IRAs") may be
used by most individuals who have taxable compensation. Simplified Employee
Pensions ("SEPs") and Defined Contribution Plans (Profit Sharing or Money
Purchase Pension Plans) may be used by most employers, including corporations,
partnerships and sole proprietors, for the benefit of business owners and their
employees. Education IRAs allow individuals, subject to certain income
limitations, to contribute up to $500 annually on behalf of any child under the
age of 18. In addition, the Fund offers a Section 403(b)(7) Plan for employees
of educational organizations and other qualifying tax-exempt organizations.
Investors should consult their tax advisor or legal counsel before selecting a
tax-deferred account.
    
 
   
     Contributions under Regular and Roth IRAs, Education IRAs, SEPs, Defined
Contribution Plans and Section 403(b)(7) Plans are subject to specific
contribution limitations. Generally, such contributions may be invested at the
direction of the participant. The investment is then held by Investors Fiduciary
Trust Company as custodian. Each participant's account is charged an annual fee
of $12. There is a maximum annual fee of $24 per taxpayer identification number.
The Fund reserves the right to change the amount of this fee or to waive it in
whole or in part for certain types of accounts.
    
 
                                       33
<PAGE>   
 
   
     Distributions from tax-deferred accounts may be subject to ordinary income
tax and may be subject to an additional 10% tax if withdrawn prior to age 59 1/2
or used for a nonqualifying purpose. Additionally, shareholders generally must
start withdrawing retirement plan assets no later than April 1 of the year after
they reach age 70 1/2. Several exceptions to these general rules may apply and
several methods exist to determine the amount and timing of the minimum annual
distribution (if any). Shareholders should consult with their tax advisor or
legal counsel prior to receiving any distribution from any tax-deferred account,
in order to determine the income tax impact of any such distribution.
    
 
   
     To receive additional information about Regular and Roth IRAs, SEPs,
Defined Contribution Plans and Section 403(b)(7) Plans along with the necessary
materials to establish an account, please call the Fund at 1-800-525-3713 or
write to the Fund at P.O. Box 173375, Denver, Colorado 80217-3375. No
contribution to a Regular or Roth IRA, SEP, Defined Contribution Plan or Section
403(b)(7) Plan can be made until the appropriate forms to establish any such
plan have been completed.
    
 
                           INCOME DIVIDENDS, CAPITAL
                            GAINS DISTRIBUTIONS AND
                                   TAX STATUS
 
     It is a policy of the Fund to make distributions of substantially all of
its investment income and any net realized capital gains. Any capital gains
realized during each fiscal year of the Fund ended October 31, as defined by the
Code, are normally declared and payable to shareholders in December. The Fund
intends to qualify as a regulated investment company by satisfying certain
requirements prescribed by Subchapter M of the Code.
 
     The Fund may purchase securities of certain foreign corporations considered
to be passive foreign investment companies by the IRS. In order to avoid taxes
and interest that must be paid by the Fund, if these instruments are profitable,
the Fund may make various elections permitted by the tax laws. However, these
elections could require that the Fund recognize taxable income, which in turn
must be distributed.
 
     Some foreign securities purchased by the Fund may be subject to foreign
taxes which could reduce the yield on such securities. The amount of such
foreign taxes is expected to be insignificant. Accordingly, the Fund does not
intend to make the election permitted under section 853 of the Code to pass
through such taxes to shareholders as a foreign tax credit as this would
increase the taxable income reported to shareholders and require shareholders to
take the credit on their tax returns, complicating the preparation of such
returns. As a result, any foreign taxes paid or accrued will represent an
expense to the Fund which will reduce its investment company taxable income.
 
                                       34
<PAGE>   
 
                             PRINCIPAL SHAREHOLDERS
 
   
     [TO BE FILED BY AMENDMENT]
    
 
                           MISCELLANEOUS INFORMATION
 
   
     The Fund was originally organized in 1984 as a Maryland corporation. On
August 7, 1992, the Fund was reorganized from a Maryland corporation into Janus
Venture Fund, a separate series of the Trust. Pursuant to this reorganization,
the Trust assumed all the assets and liabilities of Janus Venture Fund, Inc.,
and shareholders received shares of Janus Venture Fund series of the Trust equal
both in number and net asset value to their shares of Janus Venture Fund, Inc.
All references in this SAI to the Fund and all financial and other information
about the Fund prior to August 7, 1992 are to the former Janus Venture Fund,
Inc.; all references after August 7, 1992, are to the Janus Venture Fund series
of the Trust. As the result of the reorganization, the fiscal year end of the
Fund changed from July 31 to October 31. As of the date of this SAI, the Trust
consists of 18 other series.
    
 
     Janus Capital reserves the right to the name "Janus." In the event that
Janus Capital does not continue to provide investment advice to the Fund, the
Fund must cease to use the name "Janus" as soon as reasonably practicable.
 
     Under Massachusetts law, shareholders of the Fund could, under certain
circumstances, be held liable for the obligations of the Fund. However, the
Declaration of Trust disclaims shareholder liability for acts or obligations of
the Fund and requires that notice of this disclaimer be given in each agreement,
obligation or instrument entered into or executed by the Fund or the Trustees.
The Declaration of Trust also provides for indemnification from the assets of
the Fund for all losses and expenses of any Fund shareholder held liable for the
obligations of the Fund. Thus, the risk of a shareholder incurring a financial
loss on account of its liability as a shareholder of the Fund is limited to
circumstances in which the Fund would be unable to meet its obligations. The
possibility that these circumstances would occur is remote. The Trustees intend
to conduct the operations of the Fund to avoid, to the extent possible,
liability of shareholders for liabilities of the Fund.
 
SHARES OF THE TRUST
     The Trust is authorized to issue an unlimited number of shares of
beneficial interest with a par value of one cent per share for each series of
the Trust. Shares of the Fund are fully paid and nonassessable when issued. All
shares of the Fund participate equally in dividends and other distributions by
the Fund, and in residual assets of the Fund in the event of liquidation. Shares
of the Fund have no preemptive, conversion or subscription rights. Shares of the
Fund may be transferred by endorsement or stock power as is customary, but the
Fund is not bound to recognize any transfer until it is recorded on its books.
 
                                       35
<PAGE>   
 
VOTING RIGHTS
     The present Trustees were elected at a meeting of shareholders held on July
10, 1992, with the exception of Mr. Craig and Mr. Rothe who were appointed by
the Trustees as of June 30, 1995 and January 1, 1997, respectively. Under the
Declaration of Trust, each Trustee will continue in office until the termination
of the Trust or his earlier death, retirement, resignation, bankruptcy,
incapacity or removal. Vacancies will be filled by a majority of the remaining
Trustees, subject to the 1940 Act. Therefore, no annual or regular meetings of
shareholders normally will be held, unless otherwise required by the Declaration
of Trust or the 1940 Act. Subject to the foregoing, shareholders have the power
to vote to elect or remove Trustees, to terminate or reorganize the Fund, to
amend the Declaration of Trust, to bring certain derivative actions and on any
other matters on which a shareholder vote is required by the 1940 Act, the
Declaration of Trust, the Trust's Bylaws or the Trustees.
 
   
     Each share of the Fund and of each other series of the Trust has one vote
(and fractional votes for fractional shares). Shares of all series of the Trust
have noncumulative voting rights, which means that the holders of more than 50%
of the shares of all series of the Trust voting for the election of Trustees can
elect 100% of the Trustees if they choose to do so and, in such event, the
holders of the remaining shares will not be able to elect any Trustees. The Fund
and each other series of the Trust will vote separately only with respect to
those matters that affect only that series or if a series' interest in a matter
differs from the interests of other series of the Trust.
    
 
INDEPENDENT ACCOUNTANTS
     Price Waterhouse LLP, 950 Seventeenth Street, Suite 2500, Denver, Colorado
80202, independent accountants for the Fund, audit the Fund's annual financial
statements and prepare its tax returns.
 
REGISTRATION STATEMENT
     The Trust has filed with the SEC, Washington, D.C., a Registration
Statement under the Securities Act of 1933, as amended, with respect to the
securities to which this SAI relates. If further information is desired with
respect to the Fund or such securities, reference is made to the Registration
Statement and the exhibits filed as a part thereof.
 
                            PERFORMANCE INFORMATION
 
     The Prospectus contains a brief description of how performance is
calculated.
 
     Quotations of average annual total return for the Fund will be expressed in
terms of the average annual compounded rate of return of a hypothetical
investment in the Fund over periods of 1, 5, and 10 years (up to the life of the
Fund). These are the annual total rates of return that would equate the initial
amount invested to the ending redeemable value. These rates of return are
calculated pursuant to the following formula: P(1 + T)n = ERV (where P = a
hypothetical initial payment of $1,000, T = the average annual total return,
n = the number of years and ERV = the ending redeemable value of a hypothetical
$1,000 payment made at the beginning of the period). All total
 
                                       36
<PAGE>   
 
return figures reflect the deduction of a proportional share of Fund expenses on
an annual basis, and assume that all dividends and distributions are reinvested
when paid.
 
   
     The Fund was made available for public sale on May 2, 1985. The one year,
five year, ten year and lifetime average annual total returns, computed as of
October 31, 1997, for each of those periods, are [TO BE FILED BY AMENDMENT]
     %,      %,      % and      %, respectively.
    
 
   
     From time to time in advertisements or sales material, the Fund may discuss
its performance ratings or other information as published by recognized mutual
fund statistical rating services, including, but not limited to, Lipper
Analytical Services, Inc., Ibbotson Associates, Micropal or Morningstar, Inc. or
by publications of general interest such as Forbes, Money, The Wall Street
Journal, Mutual Funds Magazine, Kiplinger's or Smart Money. The Fund may also
compare its performance to that of other selected mutual funds, mutual fund
averages or recognized stock market indicators, including, but not limited to,
the Standard & Poor's 500 Composite Stock Price Index, the Standard & Poor's 400
Midcap Index, the Dow Jones Industrial Average, the Russell 2000 Index and the
NASDAQ composite. In addition, the Fund may compare its total return to the
yield on U.S. Treasury obligations and to the percentage change in the Consumer
Price Index. Such performance ratings or comparisons may be made with funds that
may have different investment restrictions, objectives, policies or techniques
than the Fund and such other funds or market indicators may be comprised of
securities that differ significantly from the Fund's investments.
    
 
                              FINANCIAL STATEMENTS
 
   
     The following audited financial statements for the period ended October 31,
1997 are hereby incorporated into this SAI by reference to the Fund's Annual
Report dated October 31, 1997. A copy of such report accompanies this SAI.
    
 
DOCUMENTS INCORPORATED BY REFERENCE TO THE ANNUAL REPORT:
 
   
     [TO BE FILED BY AMENDMENT]
    
 
   
     Schedule of Investments as of October 31, 1997
    
 
   
     Statement of Operations for the period ended October 31, 1997
    
 
   
     Statement of Assets and Liabilities as of October 31, 1997
    
 
   
     Statements of Changes in Net Assets for the periods ended October 31, 1997
and
       1996
    
 
     Financial Highlights for each of the periods indicated
 
     Notes to Financial Statements
 
     Report of Independent Accountants
 
     The portions of such Annual Report that are not specifically listed above
are not incorporated by reference into this SAI and are not part of the
Registration Statement.
 
                                       37
<PAGE>   
 
   
                                   APPENDIX A
    
 
EXPLANATION OF RATING CATEGORIES
   
     The following is a description of credit ratings issued by two of the major
credit ratings agencies. Credit ratings evaluate only the safety of principal
and interest payments, not the market value risk of lower quality securities.
Credit rating agencies may fail to change credit ratings to reflect subsequent
events on a timely basis. Although Janus Capital considers security ratings when
making investment decisions, it also performs its own investment analysis and
does not rely solely on the ratings assigned by credit agencies.
    
 
STANDARD & POOR'S RATINGS SERVICES
 
<TABLE>
<S>                  <C>
BOND RATING          EXPLANATION
- ------------------------------------------------------------------------
INVESTMENT GRADE
AAA                  Highest rating; extremely strong capacity to pay
                     principal and interest.
AA                   High quality; very strong capacity to pay principal
                     and interest.
A                    Strong capacity to pay principal and interest;
                     somewhat more susceptible to the adverse effects of
                     changing circumstances and economic conditions.
BBB                  Adequate capacity to pay principal and interest;
                     normally exhibit adequate protection parameters,
                     but adverse economic conditions or changing
                     circumstances more likely to lead to a weakened
                     capacity to pay principal and interest than for
                     higher rated bonds.
NON-INVESTMENT GRADE
BB, B,               Predominantly speculative with respect to the
CCC, CC, C           issuer's capacity to meet required interest and
                     principal payments. BB -- lowest degree of
                     speculation; C -- the highest degree of
                     speculation. Quality and protective characteristics
                     outweighed by large uncertainties or major risk
                     exposure to adverse conditions.
D                    In default.
- ------------------------------------------------------------------------
</TABLE>
 
                                       38
<PAGE>   
 
MOODY'S INVESTORS SERVICE, INC.
 
   
<TABLE>
<S>                  <C>
BOND RATING          EXPLANATION
- ------------------------------------------------------------------------
INVESTMENT GRADE
INVESTMENT GRADE
Aaa                  Highest quality, smallest degree of investment
                     risk.
Aa                   High quality; together with Aaa bonds, they compose
                     the high-grade bond group.
A                    Upper-medium grade obligations; many favorable
                     investment attributes.
Baa                  Medium-grade obligations; neither highly protected
                     nor poorly secured. Interest and principal appear
                     adequate for the present but certain protective
                     elements may be lacking or may be unreliable over
                     any great length of time.
NON-INVESTMENT GRADE
Ba                   More uncertain, with speculative elements.
                     Protection of interest and principal payments not
                     well safeguarded during good and bad times.
B                    Lack characteristics of desirable investment;
                     potentially low assurance of timely interest and
                     principal payments or maintenance of other contract
                     terms over time.
Caa                  Poor standing, may be in default; elements of
                     danger with respect to principal or interest
                     payments.
Ca                   Speculative in a high degree; could be in default
                     or have other marked shortcomings.
C                    Lowest-rated; extremely poor prospects of ever
                     attaining investment standing.
- ------------------------------------------------------------------------
</TABLE>
    
 
     Unrated securities will be treated as noninvestment grade securities unless
the portfolio managers determine that such securities are the equivalent of
investment grade securities. Securities that have received ratings from more
than one agency are considered investment grade if at least one agency has rated
the security investment grade.
 
                                       39

<PAGE>   
 
                             JANUS INVESTMENT FUND
 
                              100 Fillmore Street
                             Denver, CO 80206-4928
                                 (800) 29JANUS
 
                      STATEMENT OF ADDITIONAL INFORMATION
   
                               FEBRUARY 17, 1998
    
 
                            JANUS MONEY MARKET FUND
                       JANUS GOVERNMENT MONEY MARKET FUND
                       JANUS TAX-EXEMPT MONEY MARKET FUND
                              Institutional Shares
 
     This Statement of Additional Information ("SAI") expands upon and
supplements the information contained in the current Prospectus for the
Institutional Shares (the "Shares") of Janus Money Market Fund, Janus Government
Money Market Fund and Janus Tax-Exempt Money Market Fund (individually, a "Fund"
and, collectively, the "Funds"). The Funds are each a separate series of Janus
Investment Fund, a Massachusetts business trust (the "Trust"). Each Fund
represents shares of beneficial interest in a separate portfolio of securities
and other assets with its own objective and policies, and is managed separately
by Janus Capital Corporation ("Janus Capital").
 
   
     This SAI is not a Prospectus and should be read in conjunction with the
Prospectus dated February 17, 1998, which is incorporated by reference into this
SAI and may be obtained from the Trust at the above phone number or address.
This SAI contains additional and more detailed information about the Funds'
operations and activities than the Prospectus.
    
 
                                      LOGO
<PAGE>   
 
                             JANUS INVESTMENT FUND
                      STATEMENT OF ADDITIONAL INFORMATION
                               TABLE OF CONTENTS
 
Investment Policies and Restrictions.......................................... 3
   
Types of Securities and Investment Techniques................................. 5
    
   
Performance Data............................................................. 10
    
   
Determination of Net Asset Value............................................. 11
    
   
Investment Adviser and Administrator......................................... 12
    
   
Custodian, Transfer Agent and Certain Affiliations........................... 15
    
   
Portfolio Transactions and Brokerage......................................... 15
    
   
Officers and Trustees........................................................ 17
    
   
Purchase of Shares........................................................... 20
    
   
Redemption of Shares......................................................... 20
    
   
Tax Deferred Accounts........................................................ 21
    
   
Shareholder Accounts......................................................... 21
    
   
Dividends and Tax Status..................................................... 21
    
   
Principal Shareholders....................................................... 22
    
   
Miscellaneous Information.................................................... 22
    
   
     Shares of the Trust..................................................... 23
    
   
     Voting Rights........................................................... 23
    
   
     Independent Accountants................................................. 24
    
   
     Registration Statement.................................................. 24
    
   
Financial Statements......................................................... 24
    
   
Appendix A - Description of Securities Ratings............................... 25
    
   
Appendix B - Description of Municipal Securities............................. 28
    
- --------------------------------------------------------------------------------
 
                                        2
<PAGE>   
 
                              INVESTMENT POLICIES
                                AND RESTRICTIONS
 
INVESTMENT OBJECTIVES
     As discussed in the Prospectus, the investment objective of each of Janus
Money Market Fund and Janus Government Money Market Fund is to seek maximum
current income to the extent consistent with stability of capital. The
investment objective of Janus Tax-Exempt Money Market Fund is to seek maximum
current income that is exempt from federal income taxes to the extent consistent
with stability of capital. There can be no assurance that a Fund will achieve
its investment objective or maintain a stable net asset value of $1.00 per
share. The investment objectives of the Funds are not fundamental and may be
changed by the Trustees of the Trust (the "Trustees") without shareholder
approval.
 
INVESTMENT RESTRICTIONS APPLICABLE TO ALL FUNDS
     As indicated in the Prospectus, each Fund has adopted certain fundamental
investment restrictions that cannot be changed without shareholder approval.
Shareholder approval means approval by the lesser of (i) more than 50% of the
outstanding voting securities of the Trust (or a particular Fund or particular
class of Shares if a matter affects just that Fund or that class of Shares), or
(ii) 67% or more of the voting securities present at a meeting if the holders of
more than 50% of the outstanding voting securities of the Trust (or a particular
Fund or class of Shares) are present or represented by proxy.
 
     As used in the restrictions set forth below and as used elsewhere in this
SAI, the term "U.S. Government Securities" shall have the meaning set forth in
the Investment Company Act of 1940, as amended (the "1940 Act"). The 1940 Act
defines U.S. Government Securities as securities issued or guaranteed by the
United States government, its agencies or instrumentalities. U.S. Government
Securities may also include repurchase agreements collateralized and municipal
securities escrowed with or refunded with escrowed U.S. government securities.
 
     The Funds have adopted the following fundamental policies:
 
     (1) With respect to 75% of its assets, a Fund may not purchase a security
other than a U.S. Government Security, if, as a result, more than 5% of the
Fund's total assets would be invested in the securities of a single issuer or
the Fund would own more than 10% of the outstanding voting securities of any
single issuer. (As noted in the Prospectus, the Funds are also currently subject
to the greater diversification standards of Rule 2a-7, which are not
fundamental.)
 
     (2) A Fund may not purchase securities if 25% or more of the value of a
Fund's total assets would be invested in the securities of issuers conducting
their principal business activities in the same industry; provided that: (i)
there is no limit on investments in U.S. Government Securities or in obligations
of domestic commercial banks (including U.S. branches of foreign banks subject
to regulations under U.S. laws applicable to domestic banks and, to the extent
that its parent is unconditionally liable for the obligation, foreign branches
of U.S. banks); (ii) this limitation shall not apply to
 
                                        3
<PAGE>   
 
a Fund's investments in municipal securities; (iii) there is no limit on
investments in issuers domiciled in a single country; (iv) financial service
companies are classified according to the end users of their services (for
example, automobile finance, bank finance and diversified finance are each
considered to be a separate industry); and (v) utility companies are classified
according to their services (for example, gas, gas transmission, electric, and
telephone are each considered to be a separate industry).
 
     (3) A Fund may not act as an underwriter of securities issued by others,
except to the extent that a Fund may be deemed an underwriter in connection with
the disposition of portfolio securities of such Fund.
 
     (4) A Fund may not lend any security or make any other loan if, as a
result, more than 25% of a Fund's total assets would be lent to other parties
(but this limitation does not apply to purchases of commercial paper, debt
securities or repurchase agreements).
 
     (5) A Fund may not purchase or sell real estate or any interest therein,
except that the Fund may invest in debt obligations secured by real estate or
interests therein or securities issued by companies that invest in real estate
or interests therein.
 
     (6) A Fund may borrow money for temporary or emergency purposes (not for
leveraging) in an amount not exceeding 25% of the value of its total assets
(including the amount borrowed) less liabilities (other than borrowings). If
borrowings exceed 25% of the value of a Fund's total assets by reason of a
decline in net assets, the Fund will reduce its borrowings within three business
days to the extent necessary to comply with the 25% limitation. Reverse
repurchase agreements or the segregation of assets in connection with such
agreements shall not be considered borrowing for the purposes of this limit.
 
     (7) Each Fund may, notwithstanding any other investment policy or
restriction (whether or not fundamental), invest all of its assets in the
securities of a single open-end management investment company with substantially
the same fundamental investment objectives, policies and restrictions as that
Fund.
 
     Each Fund has adopted the following nonfundamental investment restrictions
that may be changed by the Trustees without shareholder approval:
 
     (1) A Fund may not invest in securities or enter into repurchase agreements
with respect to any securities if, as a result, more than 10% of the Fund's net
assets would be invested in repurchase agreements not entitling the holder to
payment of principal within seven days and in other securities that are not
readily marketable ("illiquid investments"). The Trustees, or the Fund's
investment adviser acting pursuant to authority delegated by the Trustees, may
determine that a readily available market exists for certain securities such as
securities eligible for resale pursuant to Rule 144A under the Securities Act of
1933, or any successor to such rule, Section 4(2) commercial paper and municipal
lease obligations. Accordingly, such securities may not be subject to the
foregoing limitation.
 
     (2) A Fund may not purchase securities on margin, or make short sales of
securities, except for short sales against the box and the use of short-term
credit necessary for the clearance of purchases and sales of portfolio
securities.
 
                                        4
<PAGE>   
 
     (3) A Fund may not pledge, mortgage, hypothecate or encumber any of its
assets except to secure permitted borrowings or in connection with permitted
short sales.
 
     (4) A Fund may not invest in companies for the purpose of exercising
control of management.
 
   
     Under the terms of an exemptive order received from the Securities and
Exchange Commission ("SEC"), each of the Funds may borrow money from or lend
money to other funds that permit such transactions and for which Janus Capital
serves as investment adviser. All such borrowing and lending will be subject to
the above limits.  A Fund will borrow money through the program only when the
costs are equal to or lower than the cost of bank loans.  Interfund loans and
borrowings normally extend overnight, but can have a maximum duration of seven
days.  A Fund will lend through the program only when the returns are higher 
than those available from other short-term instruments (such as repurchase
agreements).  A Fund may have to borrow from a bank at a higher interest rate
if an interfund loan is called or not renewed.  Any delay in repayment to a 
lending Fund could result in a lost investment opportunity or additional 
borrowing costs. 
     
    
 
   
     For purposes of the Funds' restriction on investing in a particular
industry, the Funds will rely primarily on industry classifications as published
by Bloomberg L.P. To the extent that such classifications are so broad that the
primary economic characteristics in a single class are materially different, the
Funds may further classify issuers in accordance with industry classifications
as published by the SEC.
    
 
                            TYPES OF SECURITIES AND
                             INVESTMENT TECHNIQUES
 
     Each of the Funds may invest only in "eligible securities" as defined in
Rule 2a-7 adopted under the 1940 Act. Generally, an eligible security is a
security that (i) is denominated in U.S. dollars and has a remaining maturity of
397 days or less (as calculated pursuant to Rule 2a-7); (ii) is rated, or is
issued by an issuer with short-term debt outstanding that is rated, in one of
the two highest rating categories by any two nationally recognized statistical
rating organizations ("NRSROs") or, if only one NRSRO has issued a rating, by
that NRSRO (the "Requisite NRSROs") or is unrated and of comparable quality to a
rated security, as determined by Janus Capital; and (iii) has been determined by
Janus Capital to present minimal credit risks pursuant to procedures approved by
the Trustees. In addition, the Funds will maintain a dollar-weighted average
portfolio maturity of 90 days or less. A description of the ratings of some
NRSROs appears in Appendix A.
 
     Under Rule 2a-7, a Fund may not invest more than five percent of its total
assets in the securities of any one issuer other than U.S. Government
Securities, provided that in certain cases a Fund may invest more than 5% of its
assets in a single issuer for a period of up to three business days. Until
pending amendments to Rule 2a-7 become effective, up to 25% of Janus Tax-Exempt
Money Market Fund's assets may be invested without regard to the foregoing
limitations.
 
     Pursuant to Rule 2a-7, each Fund (except Janus Tax-Exempt Money Market
Fund) will invest at least 95% of its total assets in "first-tier" securities.
First-tier securities are eligible securities that are rated, or are issued by
an issuer with short-term debt outstanding that is rated, in the highest rating
category by the Requisite NRSROs or are unrated and of comparable quality to a
rated security. In addition, a Fund may invest in "second-tier" securities which
are eligible securities that are not first-tier securities. However, a Fund
(except for Janus Tax-Exempt Money Market Fund, in certain cases) may not invest
in a second-tier security if immediately after the acquisition thereof the
 
                                        5
<PAGE>   
 
Fund would have invested more than (i) the greater of one percent of its total
assets or one million dollars in second-tier securities issued by that issuer,
or (ii) five percent of its total assets in second-tier securities.
 
     The following discussion of types of securities in which the Funds may
invest supplements and should be read in conjunction with the Prospectus.
 
PARTICIPATION INTERESTS
     Each Fund may purchase participation interests in loans or securities in
which the Funds may invest directly. Participation interests are generally
sponsored or issued by banks or other financial institutions. A participation
interest gives a Fund an undivided interest in the underlying loans or
securities in the proportion that the Fund's interest bears to the total
principal amount of the underlying loans or securities. Participation interests,
which may have fixed, floating or variable rates, may carry a demand feature
backed by a letter of credit or guarantee of a bank or institution permitting
the holder to tender them back to the bank or other institution. For certain
participation interests, a Fund will have the right to demand payment, on not
more than seven days' notice, for all or a part of the Fund's participation
interest. The Funds intend to exercise any demand rights they may have upon
default under the terms of the loan or security, to provide liquidity or to
maintain or improve the quality of the Funds' investment portfolio. A Fund will
only purchase participation interests that Janus Capital determines present
minimal credit risks.
 
VARIABLE AND FLOATING RATE NOTES
     Janus Money Market Fund also may purchase variable and floating rate demand
notes of corporations and other entities, which are unsecured obligations
redeemable upon not more than 30 days' notice. These obligations include master
demand notes that permit investment of fluctuating amounts at varying rates of
interest pursuant to direct arrangements with the issuer of the instrument. The
issuer of these obligations often has the right, after a given period, to prepay
the outstanding principal amount of the obligations upon a specified number of
days' notice. These obligations generally are not traded, nor generally is there
an established secondary market for these obligations. To the extent a demand
note does not have a seven day or shorter demand feature and there is no readily
available market for the obligation, it is treated as an illiquid investment.
 
MORTGAGE- AND ASSET-BACKED SECURITIES
     The Funds may invest in mortgage-backed securities, which represent an
interest in a pool of mortgages made by lenders such as commercial banks,
savings and loan institutions, mortgage bankers, mortgage brokers and savings
banks. Mortgage-backed securities may be issued by governmental or
government-related entities or by non-governmental entities such as banks,
savings and loan institutions, private mortgage insurance companies, mortgage
bankers and other secondary market issuers.
 
     Interests in pools of mortgage-backed securities differ from other forms of
debt securities which normally provide for periodic payment of interest in fixed
amounts with principal payments at maturity or specified call dates. In
contrast, mortgage-backed securities provide periodic payments which consist of
interest and, in most cases,
 
                                        6
<PAGE>   
 
principal. In effect, these payments are a "pass-through" of the periodic
payments and optional prepayments made by the individual borrowers on their
mortgage loans, net of any fees paid to the issuer or guarantor of such
securities. Additional payments to holders of mortgage-backed securities are
caused by prepayments resulting from the sale of the underlying residential
property, refinancing or foreclosure, net of fees or costs which may be
incurred.
 
     As prepayment rates of individual pools of mortgage loans vary widely, it
is not possible to predict accurately the average life of a particular security.
Although mortgage-backed securities are issued with stated maturities of up to
forty years, unscheduled or early payments of principal and interest on the
underlying mortgages may shorten considerably the effective maturities.
Mortgage-backed securities may have varying assumptions for average life. The
volume of prepayments of principal on a pool of mortgages underlying a
particular security will influence the yield of that security, and the principal
returned to a Fund may be reinvested in instruments whose yield may be higher or
lower than that which might have been obtained had the prepayments not occurred.
When interest rates are declining, prepayments usually increase, with the result
that reinvestment of principal prepayments will be at a lower rate than the rate
applicable to the original mortgage-backed security.
 
     The Funds may invest in mortgage-backed securities that are issued by
agencies or instrumentalities of the U.S. government. The Government National
Mortgage Association ("GNMA") is the principal federal government guarantor of
mortgage-backed securities. GNMA is a wholly-owned U.S. government corporation
within the Department of Housing and Urban Development. GNMA Certificates are
debt securities which represent an interest in one mortgage or a pool of
mortgages which are insured by the Federal Housing Administration or the Farmers
Home Administration or are guaranteed by the Veterans Administration. The Funds
may also invest in pools of conventional mortgages which are issued or
guaranteed by agencies of the U.S. government. GNMA pass-through securities are
considered to be riskless with respect to default in that (i) the underlying
mortgage loan portfolio is comprised entirely of government-backed loans and
(ii) the timely payment of both principal and interest on the securities is
guaranteed by the full faith and credit of the U.S. government, regardless of
whether or not payments have been made on the underlying mortgages. GNMA
pass-through securities are, however, subject to the same market risk as
comparable debt securities. Therefore, the market value of a Fund's GNMA
securities can be expected to fluctuate in response to changes in prevailing
interest rate levels.
 
     Residential mortgage loans are pooled also by the Federal Home Loan
Mortgage Corporation ("FHLMC"). FHLMC is a privately managed, publicly chartered
agency created by Congress in 1970 for the purpose of increasing the
availability of mortgage credit for residential housing. FHLMC issues
participation certificates ("PCs") which represent interests in mortgages from
FHLMC's national portfolio. The mortgage loans in FHLMC's portfolio are not U.S.
government backed; rather, the loans are either uninsured with loan-to-value
ratios of 80% or less, or privately insured if the loan-to-value ratio exceeds
80%. FHLMC guarantees the timely payment of interest and ultimate collection of
principal on FHLMC PCs; the U.S. government does not guarantee any aspect of
FHLMC PCs.
 
                                        7
<PAGE>   
 
     The Federal National Mortgage Association ("FNMA") is a
government-sponsored corporation owned entirely by private shareholders. It is
subject to general regulation by the Secretary of Housing and Urban Development.
FNMA purchases residential mortgages from a list of approved seller/servicers
which include savings and loan associations, savings banks, commercial banks,
credit unions and mortgage bankers. FNMA guarantees the timely payment of
principal and interest on the pass-through securities issued by FNMA; the U.S.
government does not guarantee any aspect of the FNMA pass-through securities.
 
     The Funds may also invest in privately-issued mortgage-backed securities to
the extent permitted by their investment restrictions. Mortgage-backed
securities offered by private issuers include pass-through securities comprised
of pools of conventional residential mortgage loans; mortgage-backed bonds which
are considered to be debt obligations of the institution issuing the bonds and
which are collateralized by mortgage loans; and collateralized mortgage
obligations ("CMOs") which are collateralized by mortgage-backed securities
issued by GNMA, FHLMC or FNMA or by pools of conventional mortgages.
 
     Asset-backed securities represent direct or indirect participations in, or
are secured by and payable from, assets other than mortgage-backed assets such
as motor vehicle installment sales contracts, installment loan contracts, leases
of various types of real and personal property and receivables from revolving
credit agreements (credit cards). Asset-backed securities have yield
characteristics similar to those of mortgage-backed securities and, accordingly,
are subject to many of the same risks.
 
REVERSE REPURCHASE AGREEMENTS
     Reverse repurchase agreements are transactions in which a Fund sells a
security and simultaneously commits to repurchase that security from the buyer
at an agreed upon price on an agreed upon future date. The resale price in a
reverse repurchase agreement reflects a market rate of interest that is not
related to the coupon rate or maturity of the sold security. For certain demand
agreements, there is no agreed upon repurchase date and interest payments are
calculated daily, often based upon the prevailing overnight repurchase rate. The
Funds will use the proceeds of reverse repurchase agreements only to satisfy
unusually heavy redemption requests or for other temporary or emergency purposes
without the necessity of selling portfolio securities.
 
     Generally, a reverse repurchase agreement enables the Fund to recover for
the term of the reverse repurchase agreement all or most of the cash invested in
the portfolio securities sold and to keep the interest income associated with
those portfolio securities. Such transactions are only advantageous if the
interest cost to the Fund of the reverse repurchase transaction is less than the
cost of obtaining the cash otherwise. In addition, interest costs on the money
received in a reverse repurchase agreement may exceed the return received on the
investments made by a Fund with those monies.
 
WHEN-ISSUED AND DELAYED DELIVERY SECURITIES
     Each Fund may purchase securities on a when-issued or delayed delivery
basis. A Fund will enter into such transactions only when it has the intention
of actually acquiring the securities. To facilitate such acquisitions, the
Funds' custodian will segregate cash or high quality liquid assets in an amount
at least equal to such
 
                                        8
<PAGE>   
 
commitments. On delivery dates for such transactions, the Fund will meet its
obligations from maturities, sales of the segregated securities or from other
available sources of cash. If a Fund chooses to dispose of the right to acquire
a when-issued security prior to its acquisition, it could, as with the
disposition of any other portfolio obligation, incur a gain or loss due to
market fluctuation. At the time a Fund makes the commitment to purchase
securities on a when-issued or delayed delivery basis, it will record the
transaction as a purchase and thereafter reflect the value of such securities in
determining its net asset value.
 
INVESTMENT COMPANY SECURITIES
   
     From time to time, the Funds may invest in securities of other investment
companies. The Funds are subject to the provisions of Section 12(d)(1) of the
1940 Act. The Janus funds are seeking an amended and restated exemptive order
that would permit the non-money market funds to invest in the Janus money market
funds in excess of the limitations of Section 12(d)(1) of the 1940 Act. There is
no assurance that such amendment will be granted.
    
 
MUNICIPAL LEASES
     Janus Money Market Fund and Janus Tax-Exempt Money Market Fund may invest
in municipal leases. Municipal leases frequently have special risks not normally
associated with general obligation or revenue bonds. Leases and installment
purchase or conditional sale contracts (which normally provide for title to the
leased asset to pass eventually to the government issuer) have evolved as a
means for governmental issuers to acquire property and equipment without meeting
the constitutional and statutory requirements for the issuance of debt. The
debt-issuance limitations of many state constitutions and statutes are deemed to
be inapplicable because of the inclusion in many leases or contracts of
"non-appropriation" clauses that provide that the governmental issuer has no
obligation to make future payments under the lease or contract unless money is
appropriated for such purpose by the appropriate legislative body on a yearly or
other periodic basis. A Fund will only purchase municipal leases subject to a
non-appropriation clause when the payment of principal and accrued interest is
backed by an unconditional irrevocable letter of credit, or guarantee of a bank
or other entity that meets the criteria described in the Prospectus under
"Taxable Investments."
 
     In evaluating municipal lease obligations, Janus Capital will consider such
factors as it deems appropriate, including: (a) whether the lease can be
canceled; (b) the ability of the lease obligee to direct the sale of the
underlying assets; (c) the general creditworthiness of the lease obligor; (d)
the likelihood that the municipality will discontinue appropriating funding for
the leased property in the event such property is no longer considered essential
by the municipality; (e) the legal recourse of the lease obligee in the event of
such a failure to appropriate funding; (f) whether the security is backed by a
credit enhancement such as insurance; and (g) any limitations which are imposed
on the lease obligor's ability to utilize substitute property or services other
than those covered by the lease obligation. If a lease is backed by an
unconditional letter of credit or other unconditional credit enhancement, then
Janus Capital may determine that a lease is an eligible security solely on the
basis of its evaluation of the credit enhancement.
 
                                        9
<PAGE>   
 
     Municipal leases, like other municipal debt obligations, are subject to the
risk of non-payment. The ability of issuers of municipal leases to make timely
lease payments may be adversely impacted in general economic downturns and as
relative governmental cost burdens are allocated and reallocated among federal,
state and local governmental units. Such non-payment would result in a reduction
of income to the Funds, and could result in a reduction in the value of the
municipal lease experiencing non-payment and a potential decrease in the net
asset value of a Fund.
 
                                PERFORMANCE DATA
 
     A Fund may provide current annualized and effective annualized yield
quotations based on its daily dividends. These quotations may from time to time
be used in advertisements, shareholder reports or other communications to
shareholders. All performance information supplied by the Funds in advertising
is historical and is not intended to indicate future returns.
 
     In performance advertising, the Funds may compare their Shares' performance
information with data published by independent evaluators such as Morningstar,
Inc., Lipper Analytical Services, Inc., or CDC/Wiesenberger, IBC/Donoghue's
Money Fund Report or other companies which track the investment performance of
investment companies ("Fund Tracking Companies"). The Funds may also compare
their Shares' performance information with the performance of recognized stock,
bond and other indices, including but not limited to the Municipal Bond Buyers
Indices, the Salomon Brothers Bond Index, the Lehman Bond Index, the Standard &
Poor's 500 Composite Stock Price Index, the Dow Jones Industrial Average, U.S.
Treasury bonds, bills or notes and changes in the Consumer Price Index as
published by the U.S. Department of Commerce. The Funds may refer to general
market performance over past time periods such as those published by Ibbotson
Associates (for instance, its "Stocks, Bonds, Bills and Inflation Yearbook").
The Funds may also refer in such materials to mutual fund performance rankings
and other data published by Fund Tracking Companies. Performance advertising may
also refer to discussions of the Funds and comparative mutual fund data and
ratings reported in independent periodicals, such as newspapers and financial
magazines. The Funds may also compare the Shares' yield to those of certain U.S.
Treasury obligations or other money market instruments.
 
     Any current yield quotation of the Shares which is used in such a manner as
to be subject to the provisions of Rule 482(d) under the Securities Act of 1933,
as amended, shall consist of an annualized historical yield, carried at least to
the nearest hundredth of one percent, based on a specific seven calendar day
period. Current yield shall be calculated by (a) determining the net change
during a seven calendar day period in the value of a hypothetical account having
a balance of one Share at the beginning of the period, (b) dividing the net
change by the value of the account at the beginning of the period to obtain a
base period return, and (c) multiplying the quotient by 365/7 (i.e.,
annualizing). For this purpose, the net change in account value will reflect the
value of additional Shares purchased with dividends declared on the original
Share and dividends declared on both the original Share and any such additional
Shares, but will not reflect any realized gains or losses from the sale of
securities or any unrealized appreciation or depreciation on portfolio
securities. In addition, the Shares may advertise effective yield
 
                                       10
<PAGE>   
 
quotations. Effective yield quotations are calculated by adding 1 to the base
period return, raising the sum to a power equal to 365/7, and subtracting 1 from
the result (i.e., compounding).
 
     Janus Tax-Exempt Money Market Fund's tax equivalent yield is the rate an
investor would have to earn from a fully taxable investment in order to equal
such Shares' yield after taxes. Tax equivalent yields are calculated by dividing
Janus Tax-Exempt Money Market Fund's yield by one minus the stated federal or
combined federal and state tax rate. If only a portion of the Shares' yield is
tax-exempt, only that portion is adjusted in the calculation.
 
   
     The Shares' current yield and effective yield for the seven-day period
ended October 31, 1997 is shown below:
    
 
   
     [TO BE FILED BY AMENDMENT]
    
 
   
<TABLE>
<CAPTION>
                                             Seven-day         Effective
                 Fund Name                     Yield        Seven-day Yield
- ---------------------------------------------------------------------------
<S>                                          <C>            <C>
Janus Money Market Fund - Institutional
  Shares                                           %                 %
Janus Government Money Market Fund -
  Institutional Shares                             %                 %
Janus Tax-Exempt Money Market Fund -
  Institutional Shares*                            %                 %
- ---------------------------------------------------------------------------
</TABLE>
    
 
   
*Janus Tax-Exempt Money Market Fund Institutional Shares' tax-equivalent yield
 for the seven-day period ended October 31, 1997 was     %.
    
 
     Although published yield information is useful to investors in reviewing a
Fund's performance, investors should be aware that the Fund's yield fluctuates
from day to day and that the Fund's yield for any given period is not an
indication or representation by the Fund of future yields or rates of return on
the Shares. Also, processing organizations or other institutions may charge
their customers direct fees in connection with an investment in a Fund, which
will have the effect of reducing the Fund's net yield to those shareholders. The
yield on a class of Shares is not fixed or guaranteed, and an investment in the
Shares is not insured. Accordingly, yield information may not necessarily be
used to compare Shares with investment alternatives which, like money market
instruments or bank accounts, may provide a fixed rate of interest. In addition,
because investments in the Funds are not insured or guaranteed, yield on the
Shares may not necessarily be used to compare the Shares with investment
alternatives which are insured or guaranteed.
 
                                DETERMINATION OF
                                NET ASSET VALUE
 
   
     Pursuant to the rules of the SEC, the Trustees have established procedures
to stabilize each Fund's net asset value at $1.00 per Share. These procedures
include a review of the extent of any deviation of net asset value per Share as
a result of fluctuating interest rates, based on available market rates, from
the Fund's $1.00 amortized cost price per Share. Should that deviation exceed
1/2 of 1%, the Trustees will consider whether any action should be initiated to
eliminate or reduce material
    
 
                                       11
<PAGE>   
 
dilution or other unfair results to shareholders. Such action may include
redemption of Shares in kind, selling portfolio securities prior to maturity,
reducing or withholding dividends and utilizing a net asset value per Share as
determined by using available market quotations. Each Fund (i) will maintain a
dollar-weighted average portfolio maturity of 90 days or less; (ii) will not
purchase any instrument with a remaining maturity greater than 397 days or
subject to a repurchase agreement having a duration of greater than 397 days;
(iii) will limit portfolio investments, including repurchase agreements, to
those U.S. dollar-denominated instruments that Janus Capital has determined
present minimal credit risks pursuant to procedures established by the Trustees;
and (iv) will comply with certain reporting and recordkeeping procedures. The
Trust has also established procedures to ensure that portfolio securities meet
the Funds' high quality criteria.
 
                               INVESTMENT ADVISER
                               AND ADMINISTRATOR
 
     As stated in the Prospectus, each Fund has an Investment Advisory Agreement
with Janus Capital, 100 Fillmore Street, Denver, Colorado 80206-4928. Each
Advisory Agreement provides that Janus Capital will furnish continuous advice
and recommendations concerning the Funds' investments. The Funds have each
agreed to compensate Janus Capital for its advisory services by the monthly
payment of an advisory fee at the annual rate of .20% of the average daily net
assets of each Fund. However, Janus Capital has agreed to waive .10% of the
value of each Fund's average daily net assets of the advisory fee. Janus Capital
may modify or terminate the waiver at any time upon at least 90 days' notice to
the Trustees. In addition, the Funds pay brokerage commissions or dealer spreads
and other expenses in connection with the execution of portfolio transactions.
 
     On behalf of the Shares, each of the Funds has also entered into an
Administration Agreement with Janus Capital. Under the terms of the
Administration Agreements, each of the Funds has agreed to compensate Janus
Capital for administrative services at the annual rate of .15% of the value of
the average daily net assets of the Shares for certain services, including
custody, transfer agent fees and expenses, legal fees not related to litigation,
accounting expenses, net asset value determination and fund accounting,
recordkeeping, and blue sky registration and monitoring services, registration
fees, expenses of shareholders' meetings and reports to shareholders, costs of
preparing, printing and mailing the Shares' Prospectuses and Statements of
Additional Information to current shareholders, and other costs of complying
with applicable laws regulating the sale of Shares. Each Fund will pay those
expenses not assumed by Janus Capital, including interest and taxes, fees and
expenses of Trustees who are not affiliated with Janus Capital, audit fees and
expenses, and extraordinary costs. Janus Capital has agreed to waive a portion
of the administration fee, and accordingly the effective rate for calculating
the administration fee payable by the Shares will be .05% for that period. Janus
Capital may modify or terminate the waiver at any time upon at least 90 days'
notice to the Trustees.
 
                                       12
<PAGE>   
 
     The following table summarizes the advisory fees paid by the Funds for the
fiscal years ended October 31:
 
   
     [TO BE FILED BY AMENDMENT]
    
 
   
<TABLE>
<CAPTION>
                                1997                      1996                      1995
                       -----------------------   -----------------------   -----------------------
                        Advisory     Advisory     Advisory     Advisory     Advisory     Advisory
                       Fees Prior   Fees After   Fees Prior   Fees After   Fees Prior   Fees After
      Fund Name        to Waiver      Waiver     to Waiver      Waiver     to Waiver      Waiver
- --------------------------------------------------------------------------------------------------
<S>                    <C>          <C>          <C>          <C>          <C>          <C>
Janus Money Market
  Fund                 $            $            $3,101,530   $1,550,765    $874,302     $437,151
Janus Government
  Money Market Fund    $            $              $330,914     $165,457    $151,606      $75,803
Janus Tax-Exempt
  Money Market Fund    $            $              $140,898      $70,449     $82,622      $41,311
- --------------------------------------------------------------------------------------------------
</TABLE>
    
 
     The following table summarizes the administration fees paid by the Shares
for the fiscal years ended October 31:
 
   
     [TO BE FILED BY AMENDMENT]
    
 
   
<TABLE>
<CAPTION>
                                         1997                      1996                     1995(1)
                                -----------------------   -----------------------   ------------------------
                                  Admin-       Admin-       Admin-       Admin-       Admin-        Admin-
                                istration    istration    istration    istration     istration    istration
                                Fees Prior   Fees After   Fees Prior   Fees After   Fees Prior    Fees After
          Fund Name             to Waiver      Waiver     to Waiver      Waiver      to Waiver      Waiver
- ------------------------------------------------------------------------------------------------------------
<S>                             <C>          <C>          <C>          <C>          <C>           <C>
Janus Money Market Fund -
  Institutional Shares          $             $           $1,311,645    $437,215      $164,715     $54,905
Janus Government Money Market
  Fund - Institutional Shares   $             $              $80,097     $26,699       $20,138      $6,712
Janus Tax-Exempt Money Market
  Fund - Institutional Shares   $             $               $2,631        $877          $907        $302
- -----------------------------------------------------------------------------------------------------------
</TABLE>
    
 
(1) April 14 (inception) to October 31, 1995.
 
     Advisory fees are paid on the Fund level while administration fees are paid
on the class level.
 
   
     The Advisory Agreements for each Fund were reexecuted on July 1, 1997
(without amendment other than effective dates) and will continue in effect until
July 1, 1998, and thereafter from year to year so long as such continuance is
approved annually by a majority of the Trustees who are not parties to the
Advisory Agreements or interested persons of any such party, and by either a
majority of the Funds' outstanding voting shares or the Trustees. Each Advisory
Agreement (i) may be terminated without the payment of any penalty by any Fund
or Janus Capital on 60 days' written notice; (ii) terminates automatically in
the event of its assignment; and (iii) generally, may not be amended without the
approval of a majority of the Trustees of the affected Fund, including the
Trustees who are not interested persons of that Fund or Janus Capital and, to
the extent required by the 1940 Act, the vote of a majority of the outstanding
voting securities of that Fund.
    
 
     Janus Capital also performs investment advisory services for other mutual
funds, and for individual, charitable, corporate and retirement accounts.
Investment decisions for each account managed by Janus Capital, including the
Funds, are made independently
 
                                       13
<PAGE>   
 
from those for any other account that is or may in the future become managed by
Janus Capital or its affiliates. If, however, a number of accounts managed by
Janus Capital are contemporaneously engaged in the purchase or sale of the same
security, the orders may be aggregated and/or the transactions may be averaged
as to price and allocated equitably to each account. In some cases, this policy
might adversely affect the price paid or received by an account or the size of
the position obtained or liquidated for an account. Pursuant to an exemptive
order granted by the SEC, the Funds and other funds advised by Janus Capital may
also transfer daily uninvested cash balances into one or more joint trading
accounts. Assets in the joint trading accounts are invested in money market
instruments and the proceeds are allocated to the participating funds on a pro
rata basis.
 
     Each account managed by Janus Capital has its own investment objective and
is managed in accordance with that objective by a particular portfolio manager
or team of portfolio managers. As a result, from time to time two or more
different managed accounts may pursue divergent investment strategies with
respect to investments or categories of investments.
 
     As indicated in the Prospectus, Janus Capital does not permit portfolio
managers to purchase and sell securities for their own accounts except under the
limited exceptions contained in Janus Capital's policy regarding personal
investing by directors, officers and employees of Janus Capital and the Funds.
The policy requires investment personnel and officers of Janus Capital, inside
directors of Janus Capital and the Funds and other designated persons deemed to
have access to current trading information to pre-clear all transactions in
securities not otherwise exempt under the policy. Requests for trading authority
will be denied when, among other reasons, the proposed personal transaction
would be contrary to the provisions of the policy or would be deemed to
adversely affect any transaction then known to be under consideration for or to
have been effected on behalf of any client account, including the Funds.
 
     In addition to the pre-clearance requirement described above, the policy
subjects investment personnel, officers and directors/Trustees of Janus Capital
and the Funds to various trading restrictions and reporting obligations. All
reportable transactions are reviewed for compliance with Janus Capital's policy.
Those persons also may be required under certain circumstances to forfeit their
profits made from personal trading.
 
     The provisions of the policy are administered by and subject to exceptions
authorized by Janus Capital.
 
     Kansas City Southern Industries, Inc., a publicly traded holding company
whose primary subsidiaries are engaged in transportation, information processing
and financial services ("KCSI"), owns approximately 83% of Janus Capital. Thomas
H. Bailey, the President and Chairman of the Board of Janus Capital, owns
approximately 12% of its voting stock and, by agreement with KCSI, selects a
majority of Janus Capital's Board.
 
                                       14
<PAGE>   
 
                           CUSTODIAN, TRANSFER AGENT
                            AND CERTAIN AFFILIATIONS
 
   
     UMB Bank, N.A., P.O. Box 419226, Kansas City, Missouri 64141-6226, is the
Funds' custodian. The custodian holds the Funds' assets in safekeeping and
collects and remits the income thereon, subject to the instructions of each
Fund.
    
 
     Janus Service Corporation ("Janus Service"), P.O. Box 173375, Denver,
Colorado 80217-3375, a wholly-owned subsidiary of Janus Capital, is the Funds'
transfer agent. In addition, Janus Service provides certain other
administrative, recordkeeping and shareholder relations services to the Funds.
The Funds do not pay Janus Service a fee.
 
     Janus Distributors, Inc. ("Janus Distributors"), 100 Fillmore Street,
Denver, Colorado 80206-4928, a wholly-owned subsidiary of Janus Capital, is a
distributor of the Funds. Janus Distributors is registered as a broker-dealer
under the Securities Exchange Act of 1934 (the "Exchange Act") and is a member
of the National Association of Securities Dealers, Inc. Janus Distributors acts
as the agent of the Funds in connection with the sale of their shares in all
states in which the shares are registered and in which Janus Distributors is
qualified as a broker-dealer. Under the Distribution Agreement, Janus
Distributors continuously offers the Funds' shares and accepts orders at net
asset value. No sales charges are paid by investors. Promotional expenses in
connection with offers and sales of shares are paid by Janus Capital.
 
     Janus Capital also may make payments to selected broker-dealer firms or
institutions which were instrumental in the acquisition of shareholders for the
Funds or which performed services with respect to shareholder accounts. The
minimum aggregate size required for eligibility for such payments, and the
factors in selecting the broker-dealer firms and institutions to which they will
be made, are determined from time to time by Janus Capital.
 
                             PORTFOLIO TRANSACTIONS
                                 AND BROKERAGE
 
     Decisions as to the assignment of portfolio business for the Funds and
negotiation of its commission rates are made by Janus Capital whose policy is to
obtain the "best execution" (prompt and reliable execution at the most favorable
security price) of all portfolio transactions.
 
     In selecting brokers and dealers and in negotiating commissions, Janus
Capital considers a number of factors, including but not limited to: Janus
Capital's knowledge of currently available negotiated commission rates or prices
of securities currently available and other current transaction costs; the
nature of the security being traded; the size and type of the transaction; the
nature and character of the markets for the security to be purchased or sold;
the desired timing of the trade; the activity existing and expected in the
market for the particular security; confidentiality; the quality of the
execution, clearance and settlement services; financial stability of the broker
or dealer; the existence of actual or apparent operational problems of any
broker or dealer; and research products or services provided. In recognition of
the value of the foregoing
 
                                       15
<PAGE>   
 
factors, Janus Capital may place portfolio transactions with a broker or dealer
with whom it has negotiated a commission that is in excess of the commission
another broker or dealer would have charged for effecting that transaction if
Janus Capital determines in good faith that such amount of commission was
reasonable in relation to the value of the brokerage and research provided by
such broker or dealer viewed in terms of either that particular transaction or
of the overall responsibilities of Janus Capital. These research and other
services may include, but are not limited to, general economic and security
market reviews, industry and company reviews, evaluations of securities,
recommendations as to the purchase and sale of securities and access to third
party publications, computer and electronic equipment and software. Research
received from brokers or dealers is supplemental to Janus Capital's own research
efforts.
 
   
     For the fiscal year ended October 31, 1997, the total brokerage commissions
paid by the Funds to brokers and dealers in transactions identified for
execution primarily on the basis of research and other services provided to the
Funds are summarized below:
    
 
   
     [TO BE FILED BY AMENDMENT]
    
 
   
<TABLE>
<CAPTION>
               Fund Name                  Commissions         Transactions
- --------------------------------------------------------------------------
<S>                                       <C>                 <C>
Janus Money Market Fund                      $                     $
Janus Government Money Market Fund           $                     $
Janus Tax-Exempt Money Market Fund           $                     $
- --------------------------------------------------------------------------
</TABLE>
    
 
   
     For the fiscal years ended October 31, 1997, October 31, 1996 and October
31, 1995, the total brokerage commissions paid by the Funds are summarized
below:
    
 
   
     [TO BE FILED BY AMENDMENT]
    
 
   
<TABLE>
<CAPTION>
                 Fund Name                      1997        1996       1995
- ---------------------------------------------------------------------------
<S>                                            <C>         <C>         <C>
Janus Money Market Fund                          $         $4,851      $0
Janus Government Money Market Fund               $           $0        $0
Janus Tax-Exempt Money Market Fund               $           $0        $0
- ---------------------------------------------------------------------------
</TABLE>
    
 
     The Funds generally buy and sell securities in principal transactions, in
which no commissions are paid. However, the Funds may engage an agent and pay
commissions for such transactions if Janus Capital believes that the net result
of the transaction to the respective Fund will be no less favorable than that of
contemporaneously available principal transactions.
 
     Janus Capital may use research products and services in servicing other
accounts in addition to the Funds. If Janus Capital determines that any research
product or service has a mixed use, such that it also serves functions that do
not assist in the investment decision-making process, Janus Capital may allocate
the costs of such service or product accordingly. Only that portion of the
product or service that Janus Capital determines will assist it in the
investment decision-making process may be paid for in brokerage commission
dollars. Such allocation may create a conflict of interest for Janus Capital.
 
     Janus Capital may consider sales of Shares by a broker-dealer or the
recommendation of a broker-dealer to its customers that they purchase Shares as
a factor in the selection of broker-dealers to execute Fund portfolio
transactions. Janus Capital may also consider payments made by brokers effecting
transactions for a Fund (i) to the
 
                                       16
<PAGE>   
 
Fund or (ii) to other persons on behalf of the Fund for services provided to the
Fund for which it would be obligated to pay. In placing portfolio business with
such broker-dealers, Janus Capital will seek the best execution of each
transaction.
 
     When the Funds purchase or sell a security in the over-the-counter market,
the transaction takes place directly with a principal market-maker, without the
use of a broker, except in those circumstances where in the opinion of Janus
Capital better prices and executions will be achieved through the use of a
broker.
 
   
     As of October 31, 1997, certain Funds owned securities of their regular
broker-dealers (or parents), as shown below:
    
 
   
     [TO BE FILED BY AMENDMENT]
    
 
   
<TABLE>
<CAPTION>
                                                                  Value of
                                        Name of                  Securities
       Fund Name                     Broker-Dealer                 Owned
- ----------------------------------------------------------------------------
<S>                      <C>                                    <C>
</TABLE>
    
 
                             OFFICERS AND TRUSTEES
 
     The following are the names of the Trustees and officers of the Trust,
together with a brief description of their principal occupations during the last
five years.
 
Thomas H. Bailey*# - Trustee, Chairman and President
100 Fillmore Street
Denver, CO 80206-4928
     Trustee, Chairman and President of Janus Aspen Series. Chairman, Chief
     Executive Officer, Director and President of Janus Capital. Chairman and
     Director of IDEX Management, Inc., Largo, Florida (50% subsidiary of Janus
     Capital and investment adviser to a group of mutual funds) ("IDEX").
 
James P. Craig, III*# - Trustee
100 Fillmore Street
Denver, CO 80206-4928
   
     Trustee and Executive Vice President of Janus Aspen Series. Chief
     Investment Officer, Vice President and Director of Janus Capital. Executive
     Vice President and Portfolio Manager of Janus Fund. Executive Vice
     President and Co-Manager of Janus Venture Fund.
    
 
Sharon S. Pichler* - Executive Vice President
100 Fillmore Street
Denver, CO 80206-4928
     Executive Vice President and Portfolio Manager of Janus Money Market Fund,
     Janus Tax-Exempt Money Market Fund and Janus Government Money Market Fund.
     Vice President of Janus Capital. Formerly, Assistant Vice President and
     Portfolio Manager at USAA Investment Management Co. (1990-1994).
 
- --------------------------------------------------------------------------------
*Interested person of the Trust and of Janus Capital.
#Member of the Trust's Executive Committee.
 
                                       17
<PAGE>   
 
   
Steven R. Goodbarn* - Vice President and Chief Financial Officer
100 Fillmore Street
Denver, CO 80206-4928
    
   
     Vice President and Chief Financial Officer of Janus Aspen Series. Vice
     President of Finance, Treasurer and Chief Financial Officer of Janus
     Service, Janus Distributors and Janus Capital. Director of IDEX, Janus
     Service and Janus Distributors. Director, Treasurer and Vice President of
     Finance of Janus Capital International Ltd. Formerly (May 1992-January
     1996), Treasurer of Janus Investment Fund and Janus Aspen Series.
    
 
Glenn P. O'Flaherty* - Treasurer and Chief Accounting Officer
100 Fillmore Street
Denver, CO 80206-4928
     Treasurer and Chief Accounting Officer of Janus Aspen Series. Director of
     Fund Accounting of Janus Capital.
 
Kelley Abbott Howes* - Secretary
100 Fillmore Street
Denver, CO 80206-4928
   
     Secretary of Janus Aspen Series. Director and President of Janus
     Distributors. Associate Counsel of Janus Capital. Formerly (1990 to 1994),
     with The Boston Company Advisors, Inc., Boston Massachusetts (mutual fund
     administration services).
    
 
   
William D. Stewart# - Trustee
5330 Sterling Drive
Boulder, CO 80302
    
   
     Trustee of Janus Aspen Series. President of HPS Division of MKS
     Instruments, Boulder, Colorado (manufacturer of vacuum fittings and
     valves).
    
 
   
Gary O. Loo# - Trustee
102 N. Cascade Avenue, Suite 500
Colorado Springs, CO 80903
    
     Trustee of Janus Aspen Series. President and a Director of High Valley
     Group, Inc., Colorado Springs, Colorado (investments).
 
   
Dennis B. Mullen - Trustee
14103 Denver West Parkway
Golden, CO 80401
    
   
     Trustee of Janus Aspen Series. Chief Financial Officer - Boston Market
     Concepts, Boston Chicken, Inc., Golden, Colorado (restaurant chain).
     Formerly (1993-1997), President and Chief Executive Officer of BC
     Northwest, L.P., a franchise of Boston Chicken, Inc., Bellevue, Washington
     (restaurant chain).
    
 
- --------------------------------------------------------------------------------
   
*Interested person of the Trust and of Janus Capital.
    
   
#Member of the Trust's Executive Committee.
    
 
                                       18
<PAGE>   
 
Martin H. Waldinger - Trustee
4940 Sandshore Court
San Diego, CA 92130
   
     Trustee of Janus Aspen Series. Private Consultant. Formerly (1993 to 1996),
     Director of Run Technologies, Inc., a software development firm, San
     Carlos, California. Formerly (1989 to 1993), President and Chief Executive
     Officer of Bridgecliff Management Services, Campbell, California (a
     condominium association management company).
    
 
James T. Rothe - Trustee
102 South Tejon Street, Suite 1100
Colorado Springs, CO 80903
     Trustee of Janus Aspen Series. Professor of Business, University of
     Colorado, Colorado Springs, Colorado. Principal, Phillips-Smith Retail
     Group, Colorado Springs, Colorado (a venture capital firm). Formerly
     (1986-1994), Dean of the College of Business, University of Colorado,
     Colorado Springs, Colorado.
 
     The Trustees are responsible for major decisions relating to each Fund's
objective, policies and techniques. The Trustees also supervise the operation of
the Funds by their officers and review the investment decisions of the officers
although they do not actively participate on a regular basis in making such
decisions.
 
   
     The Trust's Executive Committee shall have and may exercise all the powers
and authority of the Trustees except for matters requiring action by all
Trustees pursuant to the Trust's Bylaws or Declaration of Trust, Massachusetts
Law or the 1940 Act.
    
 
   
     The Money Market Funds Committee, consisting of Messrs. Loo, Mullen and
Rothe, monitors the compliance with policies and procedures adopted particularly
for money market funds.
    
 
     The following table shows the aggregate compensation earned by and paid to
each Trustee by the Funds described in this SAI and all funds advised and
sponsored by Janus Capital (collectively, the "Janus Funds") for the periods
indicated. None of the Trustees receive any pension or retirement benefits from
the Funds or the Janus Funds.
 
   
<TABLE>
<CAPTION>
                           AGGREGATE COMPENSATION      TOTAL COMPENSATION
                             FROM THE FUNDS FOR     FROM THE JANUS FUNDS FOR
                             FISCAL YEAR ENDED         CALENDAR YEAR ENDED
                              OCTOBER 31, 1997         DECEMBER 31, 1997**
                              [TO BE FILED BY            [TO BE FILED BY
NAME OF PERSON, POSITION         AMENDMENT]                AMENDMENT]
- -----------------------------------------------------------------------------
<S>                        <C>                      <C>
Thomas H. Bailey,
  Chairman*                      $                         $
James P. Craig, III,
  Trustee*                       $                         $
William D. Stewart,
  Trustee                        $                         $
Gary O. Loo, Trustee             $                         $
Dennis B. Mullen, Trustee        $                         $
Martin H. Waldinger,
  Trustee                        $                         $
James T. Rothe, Trustee          $                         $
- -----------------------------------------------------------------------------
</TABLE>
    
 
 *An interested person of the Funds and of Janus Capital. Compensated by Janus
  Capital and not the Funds.
   
**As of December 31, 1997, Janus Funds consisted of two registered investment
  companies comprised of a total of 32 funds.
    
 
                                       19
<PAGE>   
 
                               PURCHASE OF SHARES
 
     As stated in the Prospectus, Janus Distributors is a distributor of the
Funds' shares. Shares are sold at the net asset value per share as determined at
the close of the regular trading session of the New York Stock Exchange (the
"NYSE" or the "Exchange") next occurring after a purchase order is received and
accepted by a Fund. A Fund's net asset value is calculated each day that both
the NYSE and the New York Federal Reserve Bank are open. As stated in the
Prospectus, the Funds each seek to maintain a stable net asset value per share
of $1.00. The Shareholder's Guide Section of the Prospectus contains detailed
information about the purchase of Shares.
 
REINVESTMENT OF DIVIDENDS AND DISTRIBUTIONS
   
     If investors do not elect in writing or by phone to receive their dividends
and distributions via wire transfer, all income dividends and capital gains
distributions, if any, on Shares are reinvested automatically in additional
Shares of that Fund at the NAV determined on the first business day following
the record date. Any such election (which may be made on the Application or by
phone) will apply to dividends and distributions the record dates of which fall
on or after the date that a Fund receives such notice. Changes to distribution
options must be received at least three days prior to the record date to be
effective for such date. Investors receiving distributions and dividends via
wire transfer may elect in writing or by phone to change back to automatic
reinvestment at any time.
    
 
                              REDEMPTION OF SHARES
 
     Procedures for redemption of Shares are set forth in the Shareholder's
Guide section of the Prospectus. Shares normally will be redeemed for cash (via
wire), although each Fund retains the right to redeem Shares in kind under
unusual circumstances, in order to protect the interests of remaining
shareholders, by delivery of securities selected from its assets at its
discretion. However, the Funds are governed by Rule 18f-1 under the 1940 Act,
which requires each Fund to redeem Shares solely in cash up to the lesser of
$250,000 or 1% of the net asset value of that Fund during any 90-day period for
any one shareholder. Should redemptions by any shareholder exceed such
limitation, their Fund will have the option of redeeming the excess in cash or
in kind. If Shares are redeemed in kind, the redeeming shareholder might incur
brokerage costs in converting the assets to cash. The method of valuing
securities used to make redemptions in kind will be the same as the method of
valuing portfolio securities described under "Determination of Net Asset Value"
and such valuation will be made as of the same time the redemption price is
determined.
 
   
     The right to require the Funds to redeem Shares may be suspended, or the
date of payment may be postponed, whenever (1) trading on the NYSE is
restricted, as determined by the SEC, or the NYSE is closed except for holidays
and weekends, (2) the SEC permits such suspension and so orders, or (3) an
emergency exists as determined by the SEC so that disposal of securities or
determination of NAV is not reasonably practicable.
    
 
                                       20
<PAGE>   
 
   
                             TAX DEFERRED ACCOUNTS
    
 
     The Funds offer tax-deferred retirement plans for rollover accounts in
excess of $250,000. The Individual Retirement Account ("IRA") may be used by
individuals who meet the above requirement.
 
   
     Contributions under Regular and Roth IRAs, SEPs, Defined Contribution Plans
and Section 403(b)(7) Plans are subject to specific contribution limitations.
Generally, such contributions may be invested at the direction of the
participant. The investment is then held by Investors Fiduciary Trust Company as
custodian.
    
 
   
     Distributions from tax-deferred accounts may be subject to ordinary income
tax and may be subject to an additional 10% tax if withdrawn prior to age 59 1/2
or used for a nonqualifying purpose. Additionally, shareholders generally must
start withdrawing retirement plan assets no later than April 1 of the year after
they reach age 70 1/2. Several exceptions to these general rules may apply and
several methods exist to determine the amount and timing of the minimum annual
distribution (if any). Shareholders should consult with their tax advisor or
legal counsel prior to receiving any distribution from any tax-deferred account,
in order to determine the income tax impact of any such distribution.
    
 
     To receive additional information about IRAs along with the necessary
materials to establish an account, please call the Funds at 1-800-525-3713 or
write the Funds at P.O. Box 173375, Denver, CO 80217-3375. No contribution to
any IRA can be made until the appropriate forms to establish any such plan have
been completed.
 
                              SHAREHOLDER ACCOUNTS
 
     Detailed information about the general procedures for shareholder accounts
is set forth in the Prospectus. Applications to open accounts may be obtained by
calling the Funds at 1-800-29JANUS or writing to the Funds at 100 Fillmore
Street, Denver, Colorado 80206-4928, Attention: Extended Services.
 
                            DIVIDENDS AND TAX STATUS
 
     Dividends representing substantially all of the net investment income and
any net realized gains on sales of securities are declared daily, Saturdays,
Sundays and holidays included, and distributed on the last business day of each
month. If a month begins on a Saturday, Sunday or holiday, dividends for those
days are declared at the end of the preceding month and distributed on the first
business day of the month. A shareholder may receive dividends via wire transfer
or may choose to have dividends automatically reinvested in a Fund's Shares. As
described in the Prospectus, Shares purchased by wire on a bank business day
will receive that day's dividend if the purchase is effected at or prior to 3:00
p.m. (New York time) for Janus Money Market Fund and Janus Government Money
Market Fund and 12:00 p.m. (New York time) for Janus Tax-
 
                                       21
<PAGE>   
 
   
Exempt Money Market Fund. Otherwise, such Shares will begin to accrue dividends
on the first bank business day following receipt of the order. Requests for
redemption of Shares will be redeemed at the next determined net asset value.
Redemption requests made by wire that are received prior to 3:00 p.m. (New York
time) for Janus Money Market Fund and Janus Government Money Market Fund and
12:00 p.m. (New York time) for Janus Tax-Exempt Money Market Fund will result in
Shares being redeemed that day. Proceeds of such a redemption will normally be
sent to the predesignated bank account on that day, but that day's dividend will
not be received. Closing times for purchase and redemption of Shares may be
changed for days in which the bond market or the NYSE close early.
    
 
     Distributions for all of the Funds (except Janus Tax-Exempt Money Market
Fund) are taxable income and are subject to federal income tax (except for
shareholders exempt from income tax), whether such distributions are received
via wire transfer or are reinvested in additional Shares. Full information
regarding the tax status of income dividends and any capital gains distributions
will be mailed to shareholders for tax purposes on or before January 31st of
each year. As described in detail in the Prospectus, Janus Tax-Exempt Money
Market Fund anticipates that substantially all income dividends it pays will be
exempt from federal income tax, although dividends attributable to interest on
taxable investments, together with distributions from any net realized short- or
long-term capital gains, are taxable.
 
     The Funds intend to qualify as regulated investment companies by satisfying
certain requirements prescribed by Subchapter M of the Internal Revenue Code of
1986.
 
   
     Some money market securities employ a trust or other similar structure to
modify the maturity, price characteristics, or quality of financial assets. For
example, put features can be used to modify the maturity of a security, or
interest rate adjustment features can be used to enhance price stability. If the
structure does not perform as intended, adverse tax or investment consequences
may result. Neither the Internal Revenue Service nor any other regulatory
authority has ruled definitively on certain legal issues presented by structured
securities. Future tax or other regulatory determinations could adversely affect
the value, liquidity, or tax treatment of the income received from these
securities or the nature and timing of distributions made by a Fund.
    
 
                             PRINCIPAL SHAREHOLDERS
 
   
     [TO BE FILED BY AMENDMENT]
    
 
   
                           MISCELLANEOUS INFORMATION
    
 
   
     Each Fund is a series of the Trust, a Massachusetts Business Trust that was
created on February 11, 1986. The Trust is an open-end management investment
company registered under the 1940 Act. As of the date of this SAI, the Trust
consists of 19 separate series, three of which currently offer three classes of
Shares. The Funds were added to the Trust as separate series on December 9,
1994.
    
 
                                       22
<PAGE>   
 
     Janus Capital reserves the right to the name "Janus." In the event that
Janus Capital does not continue to provide investment advice to the Funds, the
Funds must cease to use the name "Janus" as soon as reasonably practicable.
 
     Under Massachusetts law, shareholders of the Funds could, under certain
circumstances, be held liable for the obligations of their Fund. However, the
Agreement and Declaration of Trust (the "Declaration of Trust") disclaims
shareholder liability for acts or obligations of the Funds and requires that
notice of this disclaimer be given in each agreement, obligation or instrument
entered into or executed by the Funds or the Trustees. The Declaration of Trust
also provides for indemnification from the assets of the Funds for all losses
and expenses of any Fund shareholder held liable for the obligations of their
Fund. Thus, the risk of a shareholder incurring a financial loss on account of
its liability as a shareholder of one of the Funds is limited to circumstances
in which their Fund would be unable to meet its obligations. The possibility
that these circumstances would occur is remote. The Trustees intend to conduct
the operations of the Funds to avoid, to the extent possible, liability of
shareholders for liabilities of their Fund.
 
SHARES OF THE TRUST
     The Trust is authorized to issue an unlimited number of shares of
beneficial interest with a par value of one cent per share for each series of
the Trust. Shares of each Fund are fully paid and nonassessable when issued. All
shares of a Fund participate equally in dividends and other distributions by
such Fund, and in residual assets of that Fund in the event of liquidation.
Shares of each Fund have no preemptive, conversion or subscription rights.
 
   
     The Trust is authorized to issue multiple classes of shares for each Fund.
Currently, Janus Money Market Fund, Janus Government Money Market Fund and Janus
Tax-Exempt Money Market Fund each offer three classes of shares by separate
prospectuses. The Shares discussed in this SAI are offered only to individual,
institutional and corporate clients and foundations and trusts meeting certain
minimum investment criteria. A second class of shares, Service Shares, is
offered through banks and other financial institutions that meet minimum
investment requirements in connection with trust accounts, cash management
programs and similar programs. A third class of shares, Investor Shares, is
offered to the general public.
    
 
VOTING RIGHTS
     The present Trustees were elected at a meeting of the Trust's shareholders
held on July 10, 1992, with the exception of Mr. Craig and Mr. Rothe who were
appointed by the Trustees as of June 30, 1995 and January 1, 1997, respectively.
Under the Declaration of Trust, each Trustee will continue in office until the
termination of the Trust or his earlier death, retirement, resignation,
bankruptcy, incapacity or removal. Vacancies will be filled by a majority of the
remaining Trustees, subject to the 1940 Act. Therefore, no annual or regular
meetings of shareholders normally will be held, unless otherwise required by the
Declaration of Trust or the 1940 Act. Subject to the foregoing, shareholders
have the power to vote to elect or remove Trustees, to terminate or reorganize
their Fund, to amend the Declaration of Trust, to bring certain
 
                                       23
<PAGE>   
 
derivative actions and on any other matters on which a shareholder vote is
required by the 1940 Act, the Declaration of Trust, the Trust's Bylaws or the
Trustees.
 
     Each share of each series of the Trust has one vote (and fractional votes
for fractional shares). Shares of all series of the Trust have noncumulative
voting rights, which means that the holders of more than 50% of the shares of
all series of the Trust voting for the election of Trustees can elect 100% of
the Trustees if they choose to do so and, in such event, the holders of the
remaining shares will not be able to elect any Trustees. Each series or class of
the Trust will vote separately only with respect to those matters that affect
only that series or class or if the interest of the series or class in the
matter differs from the interests of other series or classes of the Trust.
 
INDEPENDENT ACCOUNTANTS
     Price Waterhouse LLP, 950 Seventeenth Street, Suite 2500, Denver, Colorado
80202, independent accountants for the Funds, audit the Funds' annual financial
statements and prepare their tax returns.
 
REGISTRATION STATEMENT
   
     The Trust has filed with the SEC, Washington, D.C., a Registration
Statement under the Securities Act of 1933, as amended, with respect to the
securities to which this SAI relates. If further information is desired with
respect to the Funds or such securities, reference is made to the Registration
Statement and the exhibits filed as a part thereof.
    
 
                              FINANCIAL STATEMENTS
 
   
     [TO BE FILED BY AMENDMENT]
    
 
   
     The following audited financial statements of the Funds for the period
ended October 31, 1997 are hereby incorporated into this SAI by reference to the
Funds' Annual Report dated October 31, 1997. A copy of such report accompanies
this SAI.
    
 
DOCUMENTS INCORPORATED BY REFERENCE TO THE ANNUAL REPORT
 
   
     Schedules of Investments as of October 31, 1997
    
 
   
     Statements of Operations for the period ended October 31, 1997
    
 
   
     Statements of Assets and Liabilities as of October 31, 1997
    
 
   
     Statements of Changes in Net Assets for the periods ended October 31, 1997
       and 1996
    
 
     Financial Highlights for each of the periods indicated
 
     Notes to Financial Statements
 
     Report of Independent Accountants
 
     The portions of such Annual Report that are not specifically listed above
are not incorporated by reference into this SAI and are not part of the
Registration Statement.
 
                                       24
<PAGE>   
 
                                   APPENDIX A
 
DESCRIPTION OF SECURITIES RATINGS
 
MOODY'S AND STANDARD & POOR'S
 
MUNICIPAL AND CORPORATE BONDS AND MUNICIPAL LOANS
     The two highest ratings of Standard & Poor's Ratings Services ("S&P") for
municipal and corporate bonds are AAA and AA. Bonds rated AAA have the highest
rating assigned by S&P to a debt obligation. Capacity to pay interest and repay
principal is extremely strong. Bonds rated AA have a very strong capacity to pay
interest and repay principal and differ from the highest rated issues only in a
small degree. The AA rating may be modified by the addition of a plus (+) or
minus (-) sign to show relative standing within that rating category.
 
     The two highest ratings of Moody's Investors Service, Inc. ("Moody's") for
municipal and corporate bonds are Aaa and Aa. Bonds rated Aaa are judged by
Moody's to be of the best quality. Bonds rated Aa are judged to be of high
quality by all standards. Together with the Aaa group, they comprise what are
generally known as high-grade bonds. Moody's states that Aa bonds are rated
lower than the best bonds because margins of protection or other elements make
long-term risks appear somewhat larger than Aaa securities. The generic rating
Aa may be modified by the addition of the numerals 1, 2 or 3. The modifier 1
indicates that the security ranks in the higher end of the Aa rating category;
the modifier 2 indicates a mid-range ranking; and the modifier 3 indicates that
the issue ranks in the lower end of such rating category.
 
SHORT TERM MUNICIPAL LOANS
     S&P's highest rating for short-term municipal loans is SP-1. S&P states
that short-term municipal securities bearing the SP-1 designation have a strong
capacity to pay principal and interest. Those issues rated SP-1 which are
determined to possess a very strong capacity to pay debt service will be given a
plus (+) designation. Issues rated SP-2 have satisfactory capacity to pay
principal and interest with some vulnerability to adverse financial and economic
changes over the term of the notes.
 
     Moody's highest rating for short-term municipal loans is MIG-1/VMIG-1.
Moody's states that short-term municipal securities rated MIG-1/VMIG-1 are of
the best quality, enjoying strong protection from established cash flows of
funds for their servicing or from established and broad-based access to the
market for refinancing, or both. Loans bearing the MIG-2/VMIG-2 designation are
of high quality, with margins of protection ample although not so large as in
the MIG-1/VMIG-1 group.
 
OTHER SHORT-TERM DEBT SECURITIES
     Prime-1 and Prime-2 are the two highest ratings assigned by Moody's for
other short-term debt securities and commercial paper, and A-1 and A-2 are the
two highest ratings for commercial paper assigned by S&P. Moody's uses the
numbers 1, 2 and 3 to denote relative strength within its highest classification
of Prime, while S&P uses the numbers 1, 2 and 3 to denote relative strength
within its highest classification of A. Issuers rated Prime-1 by Moody's have a
superior ability for repayment of senior short-term debt obligations and have
many of the following characteristics: leading market positions in
well-established industries, high rates of
 
                                       25
<PAGE>   
 
return on funds employed, conservative capitalization structure with moderate
reliance on debt and ample asset protection, broad margins in earnings coverage
of fixed financial charges and high internal cash generation, and well
established access to a range of financial markets and assured sources of
alternate liquidity. Issuers rated Prime-2 by Moody's have a strong ability for
repayment of senior short-term debt obligations and display many of the same
characteristics displayed by issuers rated Prime-1, but to a lesser degree.
Issuers rated A-1 by S&P carry a strong degree of safety regarding timely
repayment. Those issues determined to possess extremely strong safety
characteristics are denoted with a plus (+) designation. Issuers rated A-2 by
S&P carry a satisfactory degree of safety regarding timely repayment.
 
FITCH
- --------------------------------------------------------------------------------
 
<TABLE>
<S>            <C>
F-1+           Exceptionally strong credit quality. Issues assigned this
               rating are regarded as having the strongest degree of
               assurance for timely payment.
F-1            Very strong credit quality. Issues assigned this rating
               reflect an assurance for timely payment only slightly
               less in degree than issues rated F-1+.
F-2            Good credit quality. Issues assigned this rating have a
               satisfactory degree of assurance for timely payments, but
               the margin of safety is not as great as the F-1+ and F-1
               ratings.
</TABLE>
 
DUFF & PHELPS INC.
- --------------------------------------------------------------------------------
 
<TABLE>
<S>            <C>
Duff 1+        Highest certainty of timely payment. Short-term
               liquidity, including internal operating factors and/or
               ready access to alternative sources of funds, is clearly
               outstanding, and safety is just below risk-free U.S.
               Treasury short-term obligations.
Duff 1         Very high certainty of timely payment. Liquidity factors
               are excellent and supported by good fundamental
               protection factors. Risk factors are minor.
Duff 1-        High certainty of timely payment. Liquidity factors are
               strong and supported by good fundamental protection
               factors. Risk factors are very small.
Duff 2         Good certainty of timely payment. Liquidity factors and
               company fundamentals are sound. Although ongoing funding
               needs may enlarge total financing requirements, access to
               capital markets is good. Risk factors are small.
</TABLE>
 
THOMSON BANKWATCH, INC.
- --------------------------------------------------------------------------------
 
<TABLE>
<S>            <C>
TBW-1          The highest category; indicates a very high degree of
               likelihood that principal and interest will be paid on a
               timely basis.
TBW-2          The second highest category; while the degree of safety
               regarding timely repayment of principal and interest is
               strong, the relative degree of safety is not as high as
               for issues rated TBW-1.
TBW-3          The lowest investment grade category; indicates that
               while more susceptible to adverse developments (both
               internal and external) than obligations with higher
               ratings, capacity to service principal and interest in a
               timely fashion is considered adequate.
TBW-4          The lowest rating category; this rating is regarded as
               non-investment grade and therefore speculative.
</TABLE>
 
                                       26
<PAGE>   
 
IBCA, INC.
- --------------------------------------------------------------------------------
 
<TABLE>
<S>            <C>
A1+            Obligations supported by the highest capacity for timely
               repayment. Where issues possess a particularly strong
               credit feature, a rating of A1+ is assigned.
A2             Obligations supported by a good capacity for timely
               repayment.
A3             Obligations supported by a satisfactory capacity for
               timely repayment.
B              Obligations for which there is an uncertainty as to the
               capacity to ensure timely repayment.
C              Obligations for which there is a high risk of default or
               which are currently in default.
</TABLE>
 
- --------------------------------------------------------------------------------
 
                                       27
<PAGE>   
 
                                   APPENDIX B
 
DESCRIPTION OF MUNICIPAL SECURITIES
     MUNICIPAL NOTES generally are used to provide for short-term capital needs
and usually have maturities of one year or less. They include the following:
 
     1. PROJECT NOTES, which carry a U.S. government guarantee, are issued by
public bodies (called "local issuing agencies") created under the laws of a
state, territory, or U.S. possession. They have maturities that range up to one
year from the date of issuance. Project Notes are backed by an agreement between
the local issuing agency and the Federal Department of Housing and Urban
Development. These Notes provide financing for a wide range of financial
assistance programs for housing, redevelopment, and related needs (such as
low-income housing programs and renewal programs).
 
     2. TAX ANTICIPATION NOTES ARE issued to finance working capital needs of
municipalities. Generally, they are issued in anticipation of various seasonal
tax revenues, such as income, sales, use and business taxes, and are payable
from these specific future taxes.
 
     3. REVENUE ANTICIPATION NOTES are issued in expectation of receipt of other
types of revenues, such as Federal revenues available under the Federal Revenue
Sharing Programs.
 
     4. BOND ANTICIPATION NOTES are issued to provide interim financing until
long-term financing can be arranged. In most cases, the long-term bonds then
provide the money for the repayment of the Notes.
 
     5. CONSTRUCTION LOAN NOTES are sold to provide construction financing.
After successful completion and acceptance, many projects receive permanent
financing through the Federal Housing Administration under the Federal National
Mortgage Association ("Fannie Mae") or the Government National Mortgage
Association ("Ginnie Mae").
 
     6. TAX-EXEMPT COMMERCIAL PAPER is a short-term obligation with a stated
maturity of 365 days or less. It is issued by agencies of state and local
governments to finance seasonal working capital needs or as short-term financing
in anticipation of longer term financing.
 
     MUNICIPAL BONDS, which meet longer term capital needs and generally have
maturities of more than one year when issued, have three principal
classifications:
 
     1. GENERAL OBLIGATION BONDS are issued by such entities as states,
counties, cities, towns, and regional districts. The proceeds of these
obligations are used to fund a wide range of public projects, including
construction or improvement of schools, highways and roads, and water and sewer
systems. The basic security behind General Obligation Bonds is the issuer's
pledge of its full faith and credit and taxing power for the payment of
principal and interest. The taxes that can be levied for the payment of debt
service may be limited or unlimited as to the rate or amount of special
assessments.
 
                                       28
<PAGE>   
 
     2. REVENUE BONDS in recent years have come to include an increasingly wide
variety of types of municipal obligations. As with other kinds of municipal
obligations, the issuers of revenue bonds may consist of virtually any form of
state or local governmental entity, including states, state agencies, cities,
counties, authorities of various kinds, such as public housing or redevelopment
authorities, and special districts, such as water, sewer or sanitary districts.
Generally, revenue bonds are secured by the revenues or net revenues derived
from a particular facility, group of facilities, or, in some cases, the proceeds
of a special excise or other specific revenue source. Revenue bonds are issued
to finance a wide variety of capital projects including electric, gas, water and
sewer systems; highways, bridges, and tunnels; port and airport facilities;
colleges and universities; and hospitals. Many of these bonds provide additional
security in the form of a debt service reserve fund to be used to make principal
and interest payments. Various forms of credit enhancement, such as a bank
letter of credit or municipal bond insurance, may also be employed in revenue
bond issues. Housing authorities have a wide range of security, including
partially or fully insured mortgages, rent subsidized and/or collateralized
mortgages, and/or the net revenues from housing or other public projects. Some
authorities provide further security in the form of a state's ability (without
obligation) to make up deficiencies in the debt service reserve fund.
 
     In recent years, revenue bonds have been issued in large volumes for
projects that are privately owned and operated (see 3 below).
 
     3. PRIVATE ACTIVITY BONDS are considered municipal bonds if the interest
paid thereon is exempt from Federal income tax and are issued by or on behalf of
public authorities to raise money to finance various privately operated
facilities for business and manufacturing, housing and health. These bonds are
also used to finance public facilities such as airports, mass transit systems
and ports. The payment of the principal and interest on such bonds is dependent
solely on the ability of the facility's user to meet its financial obligations
and the pledge, if any, of real and personal property as security for such
payment.
 
     While, at one time, the pertinent provisions of the Internal Revenue Code
permitted private activity bonds to bear tax-exempt interest in connection with
virtually any type of commercial or industrial project (subject to various
restrictions as to authorized costs, size limitations, state per capita volume
restrictions, and other matters), the types of qualifying projects under the
Code have become increasingly limited, particularly since the enactment of the
Tax Reform Act of 1986. Under current provisions of the Code, tax-exempt
financing remains available, under prescribed conditions, for certain privately
owned and operated rental multi-family housing facilities, nonprofit hospital
and nursing home projects, airports, docks and wharves, mass commuting
facilities and solid waste disposal projects, among others, and for the
refunding (that is, the tax-exempt refinancing) of various kinds of other
private commercial projects originally financed with tax-exempt bonds. In future
years, the types of projects qualifying under the Code for tax-exempt financing
are expected to become increasingly limited.
 
     Because of terminology formerly used in the Internal Revenue Code,
virtually any form of private activity bond may still be referred to as an
"industrial development bond," but more and more frequently revenue bonds have
become classified according
 
                                       29
<PAGE>   
 
to the particular type of facility being financed, such as hospital revenue
bonds, nursing home revenue bonds, multi-family housing revenue bonds, single
family housing revenue bonds, industrial development revenue bonds, solid waste
resource recovery revenue bonds, and so on.
 
     OTHER MUNICIPAL OBLIGATIONS, incurred for a variety of financing purposes,
include: municipal leases, which may take the form of a lease or an installment
purchase or conditional sale contract, are issued by state and local governments
and authorities to acquire a wide variety of equipment and facilities such as
fire and sanitation vehicles, telecommunications equipment and other capital
assets. Municipal leases frequently have special risks not normally associated
with general obligation or revenue bonds. Leases and installment purchase or
conditional sale contracts (which normally provide for title to the leased asset
to pass eventually to the government issuer) have evolved as a means for
governmental issuers to acquire property and equipment without meeting the
constitutional and statutory requirements for the issuance of debt. The
debt-issuance limitations of many state constitutions and statutes are deemed to
be inapplicable because of the inclusion in many leases or contracts of
"non-appropriation" clauses that provide that the governmental issuer has no
obligation to make future payments under the lease or contract unless money is
appropriated for such purpose by the appropriate legislative body on a yearly or
other periodic basis. To reduce this risk, the Fund will only purchase municipal
leases subject to a non-appropriation clause when the payment of principal and
accrued interest is backed by an unconditional irrevocable letter of credit, or
guarantee of a bank or other entity that meets the criteria described in the
Prospectus.
 
     Tax-exempt bonds are also categorized according to whether the interest is
or is not includible in the calculation of alternative minimum taxes imposed on
individuals, according to whether the costs of acquiring or carrying the bonds
are or are not deductible in part by banks and other financial institutions, and
according to other criteria relevant for Federal income tax purposes. Due to the
increasing complexity of Internal Revenue Code and related requirements
governing the issuance of tax-exempt bonds, industry practice has uniformly
required, as a condition to the issuance of such bonds, but particularly for
revenue bonds, an opinion of nationally recognized bond counsel as to the
tax-exempt status of interest on the bonds.
 
                                       30


<PAGE>   
 
                             JANUS INVESTMENT FUND
 
                              100 Fillmore Street
                             Denver, CO 80206-4928
                      STATEMENT OF ADDITIONAL INFORMATION
                               FEBRUARY 17, 1998
 
                            JANUS MONEY MARKET FUND
                       JANUS GOVERNMENT MONEY MARKET FUND
                       JANUS TAX-EXEMPT MONEY MARKET FUND
                                 Service Shares
 
     This Statement of Additional Information ("SAI") expands upon and
supplements the information contained in the current Prospectus for the Service
Shares (the "Shares") of Janus Money Market Fund, Janus Government Money Market
Fund and Janus Tax-Exempt Money Market Fund (individually, a "Fund" and,
collectively, the "Funds"). The Funds are each a separate series of Janus
Investment Fund, a Massachusetts business trust (the "Trust"). Each Fund
represents shares of beneficial interest in a separate portfolio of securities
and other assets with its own objective and policies, and is managed separately
by Janus Capital Corporation ("Janus Capital").
 
   
     This SAI is not a Prospectus and should be read in conjunction with the
Prospectus dated February 17, 1998, which is incorporated by reference into this
SAI and may be obtained from the Trust at the above phone number or address.
This SAI contains additional and more detailed information about the Funds'
operations and activities than the Prospectus.
    
 
                                      LOGO
<PAGE>   
 
                             JANUS INVESTMENT FUND
                      STATEMENT OF ADDITIONAL INFORMATION
                               TABLE OF CONTENTS
 
Investment Policies and Restrictions.......................................... 3
   
Types of Securities and Investment Techniques................................. 5
    
   
Performance Data............................................................. 10
    
   
Determination of Net Asset Value............................................. 11
    
   
Investment Adviser and Administrator......................................... 12
    
   
Custodian, Transfer Agent and Certain Affiliations........................... 14
    
   
Portfolio Transactions and Brokerage......................................... 15
    
   
Officers and Trustees........................................................ 17
    
   
Purchase of Shares........................................................... 20
    
   
Redemptions of Shares........................................................ 20
    
   
Shareholder Accounts......................................................... 20
    
   
Dividends and Tax Status..................................................... 21
    
   
Principal Shareholders....................................................... 22
    
   
Miscellaneous Information.................................................... 22
    
   
     Shares of the Trust..................................................... 22
    
   
     Voting Rights........................................................... 23
    
   
     Independent Accountants................................................. 23
    
   
     Registration Statement.................................................. 23
    
   
Financial Statements......................................................... 24
    
   
Appendix A - Description of Securities Ratings............................... 25
    
   
Appendix B - Description of Municipal Securities............................. 28
    
- --------------------------------------------------------------------------------
 
                                        2
<PAGE>   
 
                              INVESTMENT POLICIES
                                AND RESTRICTIONS
 
INVESTMENT OBJECTIVES
     As discussed in the Prospectus, the investment objective of each of Janus
Money Market Fund and Janus Government Money Market Fund is to seek maximum
current income to the extent consistent with stability of capital. The
investment objective of Janus Tax-Exempt Money Market Fund is to seek maximum
current income that is exempt from federal income taxes to the extent consistent
with stability of capital. There can be no assurance that a Fund will achieve
its investment objective or maintain a stable net asset value of $1.00 per
share. The investment objectives of the Funds are not fundamental and may be
changed by the Trustees of the Trust (the "Trustees") without shareholder
approval.
 
INVESTMENT RESTRICTIONS APPLICABLE TO ALL FUNDS
     As indicated in the Prospectus, each Fund has adopted certain fundamental
investment restrictions that cannot be changed without shareholder approval.
Shareholder approval means approval by the lesser of (i) more than 50% of the
outstanding voting securities of the Trust (or a particular Fund or particular
class of Shares if a matter affects just that Fund or that class of Shares), or
(ii) 67% or more of the voting securities present at a meeting if the holders of
more than 50% of the outstanding voting securities of the Trust (or a particular
Fund or class of Shares) are present or represented by proxy.
 
     As used in the restrictions set forth below and as used elsewhere in this
SAI, the term "U.S. Government Securities" shall have the meaning set forth in
the Investment Company Act of 1940, as amended (the "1940 Act"). The 1940 Act
defines U.S. Government Securities as securities issued or guaranteed by the
United States government, its agencies or instrumentalities. U.S. Government
Securities may also include repurchase agreements collateralized and municipal
securities escrowed with or refunded with escrowed U.S. government securities.
 
     The Funds have adopted the following fundamental policies:
 
     (1) With respect to 75% of its assets, a Fund may not purchase a security
other than a U.S. Government Security, if, as a result, more than 5% of the
Fund's total assets would be invested in the securities of a single issuer or
the Fund would own more than 10% of the outstanding voting securities of any
single issuer. (As noted in the Prospectus, the Funds are also currently subject
to the greater diversification standards of Rule 2a-7, which are not
fundamental.)
 
     (2) A Fund may not purchase securities if 25% or more of the value of a
Fund's total assets would be invested in the securities of issuers conducting
their principal business activities in the same industry; provided that: (i)
there is no limit on investments in U.S. Government Securities or in obligations
of domestic commercial banks (including U.S. branches of foreign banks subject
to regulations under U.S. laws applicable to domestic banks and, to the extent
that its parent is unconditionally liable for the obligation, foreign branches
of U.S. banks); (ii) this limitation shall not apply to
 
                                        3
<PAGE>   
 
a Fund's investments in municipal securities; (iii) there is no limit on
investments in issuers domiciled in a single country; (iv) financial service
companies are classified according to the end users of their services (for
example, automobile finance, bank finance and diversified finance are each
considered to be a separate industry); and (v) utility companies are classified
according to their services (for example, gas, gas transmission, electric, and
telephone are each considered to be a separate industry).
 
     (3) A Fund may not act as an underwriter of securities issued by others,
except to the extent that a Fund may be deemed an underwriter in connection with
the disposition of portfolio securities of such Fund.
 
     (4) A Fund may not lend any security or make any other loan if, as a
result, more than 25% of a Fund's total assets would be lent to other parties
(but this limitation does not apply to purchases of commercial paper, debt
securities or repurchase agreements).
 
     (5) A Fund may not purchase or sell real estate or any interest therein,
except that the Fund may invest in debt obligations secured by real estate or
interests therein or securities issued by companies that invest in real estate
or interests therein.
 
     (6) A Fund may borrow money for temporary or emergency purposes (not for
leveraging) in an amount not exceeding 25% of the value of its total assets
(including the amount borrowed) less liabilities (other than borrowings). If
borrowings exceed 25% of the value of a Fund's total assets by reason of a
decline in net assets, the Fund will reduce its borrowings within three business
days to the extent necessary to comply with the 25% limitation. Reverse
repurchase agreements or the segregation of assets in connection with such
agreements shall not be considered borrowing for the purposes of this limit.
 
     (7) Each Fund may, notwithstanding any other investment policy or
restriction (whether or not fundamental), invest all of its assets in the
securities of a single open-end management investment company with substantially
the same fundamental investment objectives, policies and restrictions as that
Fund.
 
     Each Fund has adopted the following nonfundamental investment restrictions
that may be changed by the Trustees without shareholder approval:
 
     (1) A Fund may not invest in securities or enter into repurchase agreements
with respect to any securities if, as a result, more than 10% of the Fund's net
assets would be invested in repurchase agreements not entitling the holder to
payment of principal within seven days and in other securities that are not
readily marketable ("illiquid investments"). The Trustees, or the Fund's
investment adviser acting pursuant to authority delegated by the Trustees, may
determine that a readily available market exists for certain securities such as
securities eligible for resale pursuant to Rule 144A under the Securities Act of
1933, or any successor to such rule, Section 4(2) commercial paper and municipal
lease obligations. Accordingly, such securities may not be subject to the
foregoing limitation.
 
     (2) A Fund may not purchase securities on margin, or make short sales of
securities, except for short sales against the box and the use of short-term
credit necessary for the clearance of purchases and sales of portfolio
securities.
 
                                        4
<PAGE>   
 
     (3) A Fund may not pledge, mortgage, hypothecate or encumber any of its
assets except to secure permitted borrowings or in connection with permitted
short sales.
 
     (4) A Fund may not invest in companies for the purpose of exercising
control of management.
 
   
     Under the terms of an exemptive order received from the Securities and
Exchange Commission ("SEC"), each of the Funds may borrow money from or lend
money to other funds that permit such transactions and for which Janus Capital
serves as investment adviser. All such borrowing and lending will be subject to
the above limits. A Fund will borrow money through the program only when the
costs are equal to or lower than the cost of bank loans. Interfund loans and
borrowings normally extend overnight, but can have a maximum duration of seven
days. A Fund will lend through the program only when the returns are higher than
those available from other short-term instruments (such as repurchase
agreements). A Fund may have to borrow from a bank at a higher interest rate if
an interfund loan is called or not renewed. Any delay in repayment to a lending
Fund could result in a lost investment opportunity or additional borrowing
costs.
    
 
   
     For purposes of the Funds' restriction on investing in a particular
industry, the Funds will rely primarily on industry classifications as published
by Bloomberg L.P. To the extent that such classifications are so broad that the
primary economic characteristics in a single class are materially different, the
Funds may further classify issuers in accordance with industry classifications
as published by the SEC.
    
                            TYPES OF SECURITIES AND
                             INVESTMENT TECHNIQUES
 
     Each of the Funds may invest only in "eligible securities" as defined in
Rule 2a-7 adopted under the 1940 Act. Generally, an eligible security is a
security that (i) is denominated in U.S. dollars and has a remaining maturity of
397 days or less (as calculated pursuant to Rule 2a-7); (ii) is rated, or is
issued by an issuer with short-term debt outstanding that is rated, in one of
the two highest rating categories by any two nationally recognized statistical
rating organizations ("NRSROs") or, if only one NRSRO has issued a rating, by
that NRSRO (the "Requisite NRSROs") or is unrated and of comparable quality to a
rated security, as determined by Janus Capital; and (iii) has been determined by
Janus Capital to present minimal credit risks pursuant to procedures approved by
the Trustees. In addition, the Funds will maintain a dollar-weighted average
portfolio maturity of 90 days or less. A description of the ratings of some
NRSROs appears in Appendix A.
 
     Under Rule 2a-7, a Fund may not invest more than five percent of its total
assets in the securities of any one issuer other than U.S. Government
Securities, provided that in certain cases a Fund may invest more than 5% of its
assets in a single issuer for a period of up to three business days. Until
pending amendments to Rule 2a-7 become effective, up to 25% of Janus Tax-Exempt
Money Market Fund's assets may be invested without regard to the foregoing
limitations.
 
     Pursuant to Rule 2a-7, each Fund (except Janus Tax-Exempt Money Market
Fund) will invest at least 95% of its total assets in "first-tier" securities.
First-tier securities
 
                                        5
<PAGE>   
 
are eligible securities that are rated, or are issued by an issuer with
short-term debt outstanding that is rated, in the highest rating category by the
Requisite NRSROs or are unrated and of comparable quality to a rated security.
In addition, a Fund may invest in "second-tier" securities which are eligible
securities that are not first-tier securities. However, a Fund (except for Janus
Tax-Exempt Money Market Fund, in certain cases) may not invest in a second-tier
security if immediately after the acquisition thereof the Fund would have
invested more than (i) the greater of one percent of its total assets or one
million dollars in second-tier securities issued by that issuer, or (ii) five
percent of its total assets in second-tier securities.
 
     The following discussion of types of securities in which the Funds may
invest supplements and should be read in conjunction with the Prospectus.
 
PARTICIPATION INTERESTS
     Each Fund may purchase participation interests in loans or securities in
which the Funds may invest directly. Participation interests are generally
sponsored or issued by banks or other financial institutions. A participation
interest gives a Fund an undivided interest in the underlying loans or
securities in the proportion that the Fund's interest bears to the total
principal amount of the underlying loans or securities. Participation interests,
which may have fixed, floating or variable rates, may carry a demand feature
backed by a letter of credit or guarantee of a bank or institution permitting
the holder to tender them back to the bank or other institution. For certain
participation interests, a Fund will have the right to demand payment, on not
more than seven days' notice, for all or a part of the Fund's participation
interest. The Funds intend to exercise any demand rights they may have upon
default under the terms of the loan or security, to provide liquidity or to
maintain or improve the quality of the Funds' investment portfolio. A Fund will
only purchase participation interests that Janus Capital determines present
minimal credit risks.
 
VARIABLE AND FLOATING RATE NOTES
     Janus Money Market Fund also may purchase variable and floating rate demand
notes of corporations and other entities, which are unsecured obligations
redeemable upon not more than 30 days' notice. These obligations include master
demand notes that permit investment of fluctuating amounts at varying rates of
interest pursuant to direct arrangements with the issuer of the instrument. The
issuer of these obligations often has the right, after a given period, to prepay
the outstanding principal amount of the obligations upon a specified number of
days' notice. These obligations generally are not traded, nor generally is there
an established secondary market for these obligations. To the extent a demand
note does not have a seven day or shorter demand feature and there is no readily
available market for the obligation, it is treated as an illiquid investment.
 
MORTGAGE- AND ASSET-BACKED SECURITIES
     The Funds may invest in mortgage-backed securities, which represent an
interest in a pool of mortgages made by lenders such as commercial banks,
savings and loan institutions, mortgage bankers, mortgage brokers and savings
banks. Mortgage-backed securities may be issued by governmental or
government-related entities or by non-
 
                                        6
<PAGE>   
 
governmental entities such as banks, savings and loan institutions, private
mortgage insurance companies, mortgage bankers and other secondary market
issuers.
 
     Interests in pools of mortgage-backed securities differ from other forms of
debt securities which normally provide for periodic payment of interest in fixed
amounts with principal payments at maturity or specified call dates. In
contrast, mortgage-backed securities provide periodic payments which consist of
interest and, in most cases, principal. In effect, these payments are a
"pass-through" of the periodic payments and optional prepayments made by the
individual borrowers on their mortgage loans, net of any fees paid to the issuer
or guarantor of such securities. Additional payments to holders of
mortgage-backed securities are caused by prepayments resulting from the sale of
the underlying residential property, refinancing or foreclosure, net of fees or
costs which may be incurred.
 
     As prepayment rates of individual pools of mortgage loans vary widely, it
is not possible to predict accurately the average life of a particular security.
Although mortgage-backed securities are issued with stated maturities of up to
forty years, unscheduled or early payments of principal and interest on the
underlying mortgages may shorten considerably the effective maturities.
Mortgage-backed securities may have varying assumptions for average life. The
volume of prepayments of principal on a pool of mortgages underlying a
particular security will influence the yield of that security, and the principal
returned to a Fund may be reinvested in instruments whose yield may be higher or
lower than that which might have been obtained had the prepayments not occurred.
When interest rates are declining, prepayments usually increase, with the result
that reinvestment of principal prepayments will be at a lower rate than the rate
applicable to the original mortgage-backed security.
 
     The Funds may invest in mortgage-backed securities that are issued by
agencies or instrumentalities of the U.S. government. The Government National
Mortgage Association ("GNMA") is the principal federal government guarantor of
mortgage-backed securities. GNMA is a wholly-owned U.S. government corporation
within the Department of Housing and Urban Development. GNMA Certificates are
debt securities which represent an interest in one mortgage or a pool of
mortgages which are insured by the Federal Housing Administration or the Farmers
Home Administration or are guaranteed by the Veterans Administration. The Funds
may also invest in pools of conventional mortgages which are issued or
guaranteed by agencies of the U.S. government. GNMA pass-through securities are
considered to be riskless with respect to default in that (i) the underlying
mortgage loan portfolio is comprised entirely of government-backed loans and
(ii) the timely payment of both principal and interest on the securities is
guaranteed by the full faith and credit of the U.S. government, regardless of
whether or not payments have been made on the underlying mortgages. GNMA
pass-through securities are, however, subject to the same market risk as
comparable debt securities. Therefore, the market value of a Fund's GNMA
securities can be expected to fluctuate in response to changes in prevailing
interest rate levels.
 
     Residential mortgage loans are pooled also by the Federal Home Loan
Mortgage Corporation ("FHLMC"). FHLMC is a privately managed, publicly chartered
agency created by Congress in 1970 for the purpose of increasing the
availability of mortgage credit for residential housing. FHLMC issues
participation certificates ("PCs") which represent interests in mortgages from
FHLMC's national portfolio. The mortgage loans
 
                                        7
<PAGE>   
 
in FHLMC's portfolio are not U.S. government backed; rather, the loans are
either uninsured with loan-to-value ratios of 80% or less, or privately insured
if the loan-to-value ratio exceeds 80%. FHLMC guarantees the timely payment of
interest and ultimate collection of principal on FHLMC PCs; the U.S. government
does not guarantee any aspect of FHLMC PCs.
 
     The Federal National Mortgage Association ("FNMA") is a
government-sponsored corporation owned entirely by private shareholders. It is
subject to general regulation by the Secretary of Housing and Urban Development.
FNMA purchases residential mortgages from a list of approved seller/servicers
which include savings and loan associations, savings banks, commercial banks,
credit unions and mortgage bankers. FNMA guarantees the timely payment of
principal and interest on the pass-through securities issued by FNMA; the U.S.
government does not guarantee any aspect of the FNMA pass-through securities.
 
     The Funds may also invest in privately-issued mortgage-backed securities to
the extent permitted by their investment restrictions. Mortgage-backed
securities offered by private issuers include pass-through securities comprised
of pools of conventional residential mortgage loans; mortgage-backed bonds which
are considered to be debt obligations of the institution issuing the bonds and
which are collateralized by mortgage loans; and collateralized mortgage
obligations ("CMOs") which are collateralized by mortgage-backed securities
issued by GNMA, FHLMC or FNMA or by pools of conventional mortgages.
 
     Asset-backed securities represent direct or indirect participations in, or
are secured by and payable from, assets other than mortgage-backed assets such
as motor vehicle installment sales contracts, installment loan contracts, leases
of various types of real and personal property and receivables from revolving
credit agreements (credit cards). Asset-backed securities have yield
characteristics similar to those of mortgage-backed securities and, accordingly,
are subject to many of the same risks.
 
REVERSE REPURCHASE AGREEMENTS
     Reverse repurchase agreements are transactions in which a Fund sells a
security and simultaneously commits to repurchase that security from the buyer
at an agreed upon price on an agreed upon future date. The resale price in a
reverse repurchase agreement reflects a market rate of interest that is not
related to the coupon rate or maturity of the sold security. For certain demand
agreements, there is no agreed upon repurchase date and interest payments are
calculated daily, often based upon the prevailing overnight repurchase rate. The
Funds will use the proceeds of reverse repurchase agreements only to satisfy
unusually heavy redemption requests or for other temporary or emergency purposes
without the necessity of selling portfolio securities.
 
     Generally, a reverse repurchase agreement enables the Fund to recover for
the term of the reverse repurchase agreement all or most of the cash invested in
the portfolio securities sold and to keep the interest income associated with
those portfolio securities. Such transactions are only advantageous if the
interest cost to the Fund of the reverse repurchase transaction is less than the
cost of obtaining the cash otherwise. In addition, interest costs on the money
received in a reverse repurchase agreement may exceed the return received on the
investments made by a Fund with those monies.
 
                                        8
<PAGE>   
 
WHEN-ISSUED AND DELAYED DELIVERY SECURITIES
     Each Fund may purchase securities on a when-issued or delayed delivery
basis. A Fund will enter into such transactions only when it has the intention
of actually acquiring the securities. To facilitate such acquisitions, the
Funds' custodian will segregate cash or high quality liquid assets in an amount
at least equal to such commitments. On delivery dates for such transactions, the
Fund will meet its obligations from maturities, sales of the segregated
securities or from other available sources of cash. If a Fund chooses to dispose
of the right to acquire a when-issued security prior to its acquisition, it
could, as with the disposition of any other portfolio obligation, incur a gain
or loss due to market fluctuation. At the time a Fund makes the commitment to
purchase securities on a when-issued or delayed delivery basis, it will record
the transaction as a purchase and thereafter reflect the value of such
securities in determining its net asset value.
 
INVESTMENT COMPANY SECURITIES
   
     From time to time, the Funds may invest in securities of other investment
companies. The Funds are subject to the provisions of Section 12(d)(1) of the
1940 Act. The Janus funds are seeking an amended and restated exemptive order
that would permit the non-money market funds to invest in the Janus money market
funds in excess of the limitations of Section 12(d)(1) of the 1940 Act. There is
no assurance that such amendment will be granted.
    
 
MUNICIPAL LEASES
     Janus Money Market Fund and Janus Tax-Exempt Money Market Fund may invest
in municipal leases. Municipal leases frequently have special risks not normally
associated with general obligation or revenue bonds. Leases and installment
purchase or conditional sale contracts (which normally provide for title to the
leased asset to pass eventually to the government issuer) have evolved as a
means for governmental issuers to acquire property and equipment without meeting
the constitutional and statutory requirements for the issuance of debt. The
debt-issuance limitations of many state constitutions and statutes are deemed to
be inapplicable because of the inclusion in many leases or contracts of
"non-appropriation" clauses that provide that the governmental issuer has no
obligation to make future payments under the lease or contract unless money is
appropriated for such purpose by the appropriate legislative body on a yearly or
other periodic basis. A Fund will only purchase municipal leases subject to a
non-appropriation clause when the payment of principal and accrued interest is
backed by an unconditional irrevocable letter of credit, or guarantee of a bank
or other entity that meets the criteria described in the Prospectus under
"Taxable Investments."
 
     In evaluating municipal lease obligations, Janus Capital will consider such
factors as it deems appropriate, including: (a) whether the lease can be
canceled; (b) the ability of the lease obligee to direct the sale of the
underlying assets; (c) the general creditworthiness of the lease obligor; (d)
the likelihood that the municipality will discontinue appropriating funding for
the leased property in the event such property is no longer considered essential
by the municipality; (e) the legal recourse of the lease obligee in the event of
such a failure to appropriate funding; (f) whether the security is backed by a
credit enhancement such as insurance; and (g) any limitations which are
 
                                        9
<PAGE>   
 
imposed on the lease obligor's ability to utilize substitute property or
services other than those covered by the lease obligation. If a lease is backed
by an unconditional letter of credit or other unconditional credit enhancement,
then Janus Capital may determine that a lease is an eligible security solely on
the basis of its evaluation of the credit enhancement.
 
     Municipal leases, like other municipal debt obligations, are subject to the
risk of non-payment. The ability of issuers of municipal leases to make timely
lease payments may be adversely impacted in general economic downturns and as
relative governmental cost burdens are allocated and reallocated among federal,
state and local governmental units. Such non-payment would result in a reduction
of income to the Funds, and could result in a reduction in the value of the
municipal lease experiencing non-payment and a potential decrease in the net
asset value of a Fund.
 
                                PERFORMANCE DATA
 
     A Fund may provide current annualized and effective annualized yield
quotations based on its daily dividends. These quotations may from time to time
be used in advertisements, shareholder reports or other communications to
shareholders. All performance information supplied by the Funds in advertising
is historical and is not intended to indicate future returns.
 
     In performance advertising, the Funds may compare their Shares' performance
information with data published by independent evaluators such as Morningstar,
Inc., Lipper Analytical Services, Inc., or CDC/Wiesenberger, IBC/Donoghue's
Money Fund Report or other companies which track the investment performance of
investment companies ("Fund Tracking Companies"). The Funds may also compare
their Shares' performance information with the performance of recognized stock,
bond and other indices, including but not limited to the Municipal Bond Buyers
Indices, the Salomon Brothers Bond Index, the Lehman Bond Index, the Standard &
Poor's 500 Composite Stock Price Index, the Dow Jones Industrial Average, U.S.
Treasury bonds, bills or notes and changes in the Consumer Price Index as
published by the U.S. Department of Commerce. The Funds may refer to general
market performance over past time periods such as those published by Ibbotson
Associates (for instance, its "Stocks, Bonds, Bills and Inflation Yearbook").
The Funds may also refer in such materials to mutual fund performance rankings
and other data published by Fund Tracking Companies. Performance advertising may
also refer to discussions of the Funds and comparative mutual fund data and
ratings reported in independent periodicals, such as newspapers and financial
magazines. The Funds may also compare the Shares' yield to those of certain U.S.
Treasury obligations or other money market instruments.
 
     Any current yield quotation of the Shares which is used in such a manner as
to be subject to the provisions of Rule 482(d) under the Securities Act of 1933,
as amended, shall consist of an annualized historical yield, carried at least to
the nearest hundredth of one percent, based on a specific seven calendar day
period. Current yield shall be calculated by (a) determining the net change
during a seven calendar day period in the value of a hypothetical account having
a balance of one Share at the beginning of the period, (b) dividing the net
change by the value of the account at the beginning of the
 
                                       10
<PAGE>   
 
period to obtain a base period return, and (c) multiplying the quotient by 365/7
(i.e., annualizing). For this purpose, the net change in account value will
reflect the value of additional Shares purchased with dividends declared on the
original Share and dividends declared on both the original Share and any such
additional Shares, but will not reflect any realized gains or losses from the
sale of securities or any unrealized appreciation or depreciation on portfolio
securities. In addition, the Shares may advertise effective yield quotations.
Effective yield quotations are calculated by adding 1 to the base period return,
raising the sum to a power equal to 365/7, and subtracting 1 from the result
(i.e., compounding).
 
     Janus Tax-Exempt Money Market Fund's tax equivalent yield is the rate an
investor would have to earn from a fully taxable investment in order to equal
such Shares' yield after taxes. Tax equivalent yields are calculated by dividing
Janus Tax-Exempt Money Market Fund's yield by one minus the stated federal or
combined federal and state tax rate. If only a portion of the Shares' yield is
tax-exempt, only that portion is adjusted in the calculation.
 
   
     The Shares' current yield and effective yield for the seven day period
ended October 31, 1997 is shown below.
    
 
   
<TABLE>
<CAPTION>
                                             Seven-day         Effective
                 Fund Name                     Yield        Seven-day Yield
- ---------------------------------------------------------------------------
<S>                                          <C>            <C>
Janus Money Market Fund - Service Shares           %                 %
Janus Government Money Market
  Fund - Service Shares                            %                 %
Janus Tax-Exempt Money Market
  Fund - Service Shares*                           %                 %
- ---------------------------------------------------------------------------
</TABLE>
    
 
   
*Janus Tax-Exempt Money Market Fund - Service Shares tax equivalent yield for
 the seven day period ended October 31, 1997 was     %.
    
 
     Although published yield information is useful to investors in reviewing a
Fund's performance, investors should be aware that the Fund's yield fluctuates
from day to day and that the Fund's yield for any given period is not an
indication or representation by the Fund of future yields or rates of return on
the Shares. Also, Financial Institutions may charge their customers direct fees
in connection with an investment in a Fund, which will have the effect of
reducing the Fund's net yield to those shareholders. The yield on a class of
Shares is not fixed or guaranteed, and an investment in the Shares is not
insured. Accordingly, yield information may not necessarily be used to compare
Shares with investment alternatives which, like money market instruments or bank
accounts, may provide a fixed rate of interest. In addition, because investments
in the Funds are not insured or guaranteed, yield on the Shares may not
necessarily be used to compare the Shares with investment alternatives which are
insured or guaranteed.
 
                                DETERMINATION OF
                                NET ASSET VALUE
 
   
     Pursuant to the rules of the SEC, the Trustees have established procedures
to stabilize each Fund's net asset value at $1.00 per Share. These procedures
include a review of the extent of any deviation of net asset value per Share as
a result of fluctuating interest rates, based on available market rates, from
the Fund's $1.00
    
 
                                       11
<PAGE>   
 
amortized cost price per Share. Should that deviation exceed 1/2 of 1%, the
Trustees will consider whether any action should be initiated to eliminate or
reduce material dilution or other unfair results to shareholders. Such action
may include redemption of Shares in kind, selling portfolio securities prior to
maturity, reducing or withholding dividends and utilizing a net asset value per
Share as determined by using available market quotations. Each Fund (i) will
maintain a dollar-weighted average portfolio maturity of 90 days or less; (ii)
will not purchase any instrument with a remaining maturity greater than 397 days
or subject to a repurchase agreement having a duration of greater than 397 days;
(iii) will limit portfolio investments, including repurchase agreements, to
those U.S. dollar-denominated instruments that Janus Capital has determined
present minimal credit risks pursuant to procedures established by the Trustees;
and (iv) will comply with certain reporting and recordkeeping procedures. The
Trust has also established procedures to ensure that portfolio securities meet
the Funds' high quality criteria.
 
                               INVESTMENT ADVISER
                               AND ADMINISTRATOR
 
     As stated in the Prospectus, each Fund has an Investment Advisory Agreement
with Janus Capital, 100 Fillmore Street, Denver, Colorado 80206-4928. Each
Advisory Agreement provides that Janus Capital will furnish continuous advice
and recommendations concerning the Funds' investments. The Funds have each
agreed to compensate Janus Capital for its advisory services by the monthly
payment of an advisory fee at the annual rate of .20% of the average daily net
assets of each Fund. However, Janus Capital has agreed to waive .10% of the
value of each Fund's average daily net assets of the advisory fee. Janus Capital
may modify or terminate the waiver at any time upon at least 90 days' notice to
the Trustees. In addition, the Funds pay brokerage commissions or dealer spreads
and other expenses in connection with the execution of portfolio transactions.
 
     The following table summarizes the advisory fees paid by the Funds for the
fiscal years ended October 31:
 
   
<TABLE>
<CAPTION>
                                1997                      1996                      1995
                       -----------------------   -----------------------   -----------------------
                        Advisory                  Advisory                  Advisory
                          Fees       Advisory       Fees       Advisory       Fees       Advisory
                         Prior         Fees        Prior         Fees        Prior         Fees
                           to         After          to         After          to         After
      Fund Name          Waiver       Waiver       Waiver       Waiver       Waiver       Waiver
- --------------------------------------------------------------------------------------------------
<S>                    <C>          <C>          <C>          <C>          <C>          <C>
Janus Money Market
  Fund                 $            $            $3,101,530   $1,550,765    $874,302     $437,151
Janus Government
  Money Market Fund    $            $              $330,914     $165,457    $151,606      $75,803
Janus Tax-Exempt
  Money Market Fund    $            $              $140,898      $70,449     $82,622      $41,311
- --------------------------------------------------------------------------------------------------
</TABLE>
    
 
     On behalf of the Shares, each of the Funds has also entered into an
Administration Agreement with Janus Capital. Under the terms of the
Administration Agreements, each of the Funds has agreed to compensate Janus
Capital for administrative services at the
 
                                       12
<PAGE>   
 
annual rate of .40% of the value of the average daily net assets of the Shares
for certain services, including custody, transfer agent fees and expenses, legal
fees not related to litigation, accounting expenses, net asset value
determination and fund accounting, recordkeeping, and blue sky registration and
monitoring services, registration fees, expenses of shareholders' meetings and
reports to shareholders, costs of preparing, printing and mailing the Shares'
Prospectuses and Statements of Additional Information to current shareholders,
and other costs of complying with applicable laws regulating the sale of Shares.
Each Fund will pay those expenses not assumed by Janus Capital, including
interest and taxes, fees and expenses of Trustees who are not affiliated with
Janus Capital, audit fees and expenses, and extraordinary costs. Janus Capital
has agreed to waive a portion of the administration fee, and accordingly the
effective rate for calculating the administration fee payable by the Shares will
be .30% for that period. Janus Capital may terminate the waiver at any time upon
at least 90 days' notice to the Trustees.
 
     Janus Capital may use all or a portion of its administration fee to
compensate Financial Institutions for providing administrative services to their
customers who invest in the Shares. The types of services that the Financial
Institutions would provide include serving as the sole shareholder of record,
shareholder recordkeeping, processing and aggregating purchase and redemption
transactions, providing periodic statements, forwarding shareholder reports and
other materials, and providing other similar services that the Funds would have
to perform if they were dealing directly with the beneficial owners, rather than
the Financial Institutions, as shareholders of record.
 
   
     The Advisory Agreements for each Fund were reexecuted on July 1, 1997
(without amendment other than effective dates) and will continue in effect until
July 1, 1998, and thereafter from year to year so long as such continuance is
approved annually by a majority of the Trustees who are not parties to the
Advisory Agreements or interested persons of any such party, and by either a
majority of the Funds' outstanding voting shares or the Trustees. Each Advisory
Agreement (i) may be terminated without the payment of any penalty by any Fund
or Janus Capital on 60 days' written notice; (ii) terminates automatically in
the event of its assignment; and (iii) generally, may not be amended without the
approval of a majority of the Trustees of the affected Fund, including the
Trustees who are not interested persons of that Fund or Janus Capital and, to
the extent required by the 1940 Act, the vote of a majority of the outstanding
voting securities of that Fund.
    
 
     Janus Capital also performs investment advisory services for other mutual
funds, and for individual, charitable, corporate and retirement accounts.
Investment decisions for each account managed by Janus Capital, including the
Funds, are made independently from those for any other account that is or may in
the future become managed by Janus Capital or its affiliates. If, however, a
number of accounts managed by Janus Capital are contemporaneously engaged in the
purchase or sale of the same security, the orders may be aggregated and/or the
transactions may be averaged as to price and allocated equitably to each
account. In some cases, this policy might adversely affect the price paid or
received by an account or the size of the position obtained or liquidated for an
account. Pursuant to an exemptive order granted by the SEC, the Funds and other
funds advised by Janus Capital may also transfer daily uninvested cash balances
into one or more joint trading accounts. Assets in the joint trading accounts
are invested in money
 
                                       13
<PAGE>   
 
market instruments and the proceeds are allocated to the participating funds on
a pro rata basis.
 
     Each account managed by Janus Capital has its own investment objective and
is managed in accordance with that objective by a particular portfolio manager
or team of portfolio managers. As a result, from time to time two or more
different managed accounts may pursue divergent investment strategies with
respect to investments or categories of investments.
 
     As indicated in the Prospectus, Janus Capital does not permit portfolio
managers to purchase and sell securities for their own accounts except under the
limited exceptions contained in Janus Capital's policy regarding personal
investing by directors, officers and employees of Janus Capital and the Funds.
The policy requires investment personnel and officers of Janus Capital, inside
directors of Janus Capital and the Funds and other designated persons deemed to
have access to current trading information to pre-clear all transactions in
securities not otherwise exempt under the policy. Requests for trading authority
will be denied when, among other reasons, the proposed personal transaction
would be contrary to the provisions of the policy or would be deemed to
adversely affect any transaction then known to be under consideration for or to
have been effected on behalf of any client account, including the Funds.
 
     In addition to the pre-clearance requirement described above, the policy
subjects investment personnel, officers and directors/Trustees of Janus Capital
and the Funds to various trading restrictions and reporting obligations. All
reportable transactions are reviewed for compliance with Janus Capital's policy.
Those persons also may be required under certain circumstances to forfeit their
profits made from personal trading.
 
     The provisions of the policy are administered by and subject to exceptions
authorized by Janus Capital.
 
     Kansas City Southern Industries, Inc., a publicly traded holding company
whose primary subsidiaries are engaged in transportation, information processing
and financial services ("KCSI"), owns approximately 83% of Janus Capital. Thomas
H. Bailey, the President and Chairman of the Board of Janus Capital, owns
approximately 12% of its voting stock and, by agreement with KCSI, selects a
majority of Janus Capital's Board.
 
                           CUSTODIAN, TRANSFER AGENT
                            AND CERTAIN AFFILIATIONS
 
   
     UMB Bank, N.A., P.O. Box 419226, Kansas City, Missouri 64141-6226, is the
Funds' custodian. The custodian holds the Funds' assets in safekeeping and
collects and remits the income thereon, subject to the instructions of each
Fund.
    
 
     Janus Service Corporation ("Janus Service"), P.O. Box 173375, Denver,
Colorado 80217-3375, a wholly-owned subsidiary of Janus Capital, is the Funds'
transfer agent. In addition, Janus Service provides certain other
administrative, recordkeeping and shareholder relations services to the Funds.
The Funds do not pay Janus Service a fee.
 
     Janus Distributors, Inc. ("Janus Distributors"), 100 Fillmore Street,
Denver, Colorado 80206-4928, a wholly-owned subsidiary of Janus Capital, is a
distributor of the
 
                                       14
<PAGE>   
 
Funds. Janus Distributors is registered as a broker-dealer under the Securities
Exchange Act of 1934 (the "Exchange Act") and is a member of the National
Association of Securities Dealers, Inc. Janus Distributors acts as the agent of
the Funds in connection with the sale of their shares in all states in which the
shares are registered and in which Janus Distributors is qualified as a
broker-dealer. Under the Distribution Agreement, Janus Distributors continuously
offers the Funds' shares and accepts orders at net asset value. No sales charges
are paid by investors. Promotional expenses in connection with offers and sales
of shares are paid by Janus Capital.
 
     Janus Capital also may make payments to selected broker-dealer firms or
institutions which were instrumental in the acquisition of shareholders for the
Funds or which performed services with respect to shareholder accounts. The
minimum aggregate size required for eligibility for such payments, and the
factors in selecting the broker-dealer firms and institutions to which they will
be made, are determined from time to time by Janus Capital.
 
                             PORTFOLIO TRANSACTIONS
                                 AND BROKERAGE
 
     Decisions as to the assignment of portfolio business for the Funds and
negotiation of its commission rates are made by Janus Capital whose policy is to
obtain the "best execution" (prompt and reliable execution at the most favorable
security price) of all portfolio transactions.
 
     In selecting brokers and dealers and in negotiating commissions, Janus
Capital considers a number of factors, including but not limited to: Janus
Capital's knowledge of currently available negotiated commission rates or prices
of securities currently available and other current transaction costs; the
nature of the security being traded; the size and type of the transaction; the
nature and character of the markets for the security to be purchased or sold;
the desired timing of the trade; the activity existing and expected in the
market for the particular security; confidentiality; the quality of the
execution, clearance and settlement services; financial stability of the broker
or dealer; the existence of actual or apparent operational problems of any
broker or dealer; and research products or services provided. In recognition of
the value of the foregoing factors, Janus Capital may place portfolio
transactions with a broker or dealer with whom it has negotiated a commission
that is in excess of the commission another broker or dealer would have charged
for effecting that transaction if Janus Capital determines in good faith that
such amount of commission was reasonable in relation to the value of the
brokerage and research provided by such broker or dealer viewed in terms of
either that particular transaction or of the overall responsibilities of Janus
Capital. These research and other services may include, but are not limited to,
general economic and security market reviews, industry and company reviews,
evaluations of securities, recommendations as to the purchase and sale of
securities and access to third party publications, computer and electronic
equipment and software. Research received from brokers or dealers is
supplemental to Janus Capital's own research efforts.
 
                                       15
<PAGE>   
 
   
     For the fiscal year ended October 31, 1997, the total brokerage commissions
paid by the Funds to brokers and dealers in transactions identified for
execution primarily on the basis of research and other services provided to the
Funds are summarized below:
    
 
   
<TABLE>
<CAPTION>
               Fund Name                  Commissions         Transactions
- --------------------------------------------------------------------------
<S>                                       <C>                 <C>
Janus Money Market Fund                      $                     $
Janus Government Money Market Fund           $                     $
Janus Tax-Exempt Money Market Fund           $                     $
- --------------------------------------------------------------------------
</TABLE>
    
 
   
     For the fiscal years ended October 31, 1997, October 31, 1996 and October
31, 1995, the total brokerage commissions paid by the Funds are summarized
below:
    
 
   
<TABLE>
<CAPTION>
                                             1997
                                         [To be filed
             Fund Name                   by Amendment]       1996       1995
- ----------------------------------------------------------------------------
<S>                                      <C>                <C>         <C>
Janus Money Market Fund                      $              $4,851      $0
Janus Government Money Market Fund           $                $0        $0
Janus Tax-Exempt Money Market Fund           $                $0        $0
- ----------------------------------------------------------------------------
</TABLE>
    
 
     The Funds generally buy and sell securities in principal transactions, in
which no commissions are paid. However, the Funds may engage an agent and pay
commissions for such transactions if Janus Capital believes that the net result
of the transaction to the respective Fund will be no less favorable than that of
contemporaneously available principal transactions.
 
     Janus Capital may use research products and services in servicing other
accounts in addition to the Funds. If Janus Capital determines that any research
product or service has a mixed use, such that it also serves functions that do
not assist in the investment decision-making process, Janus Capital may allocate
the costs of such service or product accordingly. Only that portion of the
product or service that Janus Capital determines will assist it in the
investment decision-making process may be paid for in brokerage commission
dollars. Such allocation may create a conflict of interest for Janus Capital.
 
     Janus Capital may consider sales of Shares by a broker-dealer or the
recommendation of a broker-dealer to its customers that they purchase Shares as
a factor in the selection of broker-dealers to execute Fund portfolio
transactions. Janus Capital may also consider payments made by brokers effecting
transactions for a Fund (i) to the Fund or (ii) to other persons on behalf of
the Fund for services provided to the Fund for which it would be obligated to
pay. In placing portfolio business with such broker-dealers, Janus Capital will
seek the best execution of each transaction.
 
     When the Funds purchase or sell a security in the over-the-counter market,
the transaction takes place directly with a principal market-maker, without the
use of a broker, except in those circumstances where in the opinion of Janus
Capital better prices and executions will be achieved through the use of a
broker.
 
                                       16
<PAGE>   
 
   
     As of October 31, 1997, certain Funds owned securities of their regular
broker-dealers (or parents), as shown below:
    
 
   
<TABLE>
<CAPTION>
                                                                  Value of
                                        Name of                  Securities
       Fund Name                     Broker-Dealer                 Owned
- ----------------------------------------------------------------------------
<S>                      <C>                                    <C>
 
                         [TO BE FILED BY AMENDMENT]
 
- ----------------------------------------------------------------------------
</TABLE>
    
 
                             OFFICERS AND TRUSTEES
 
     The following are the names of the Trustees and officers of the Trust,
together with a brief description of their principal occupations during the last
five years.
 
Thomas H. Bailey*# - Trustee, Chairman and President
100 Fillmore Street
Denver, CO 80206-4928
     Trustee, Chairman and President of Janus Aspen Series. Chairman, Chief
     Executive Officer, Director and President of Janus Capital. Chairman and
     Director of IDEX Management, Inc., Largo, Florida (50% subsidiary of Janus
     Capital and investment adviser to a group of mutual funds) ("IDEX").
 
   
James P. Craig, III*# - Trustee
100 Fillmore Street
Denver, CO 80206-4928
    
   
     Trustee and Executive Vice President of Janus Aspen Series. Chief
     Investment Officer, Vice President and Director of Janus Capital. Executive
     Vice President and Portfolio Manager of Janus Fund. Executive Vice
     President and Co-Manager of Janus Venture Fund.
    
 
Sharon S. Pichler* - Executive Vice President
100 Fillmore Street
Denver, CO 80206-4928
     Executive Vice President and Portfolio Manager of Janus Money Market Fund,
     Janus Tax-Exempt Money Market Fund and Janus Government Money Market Fund.
     Vice President of Janus Capital. Formerly, Assistant Vice President and
     Portfolio Manager at USAA Investment Management Co. (1990-1994).
 
- --------------------------------------------------------------------------------
*Interested person of the Trust and of Janus Capital.
#Member of the Trust's Executive Committee.
 
                                       17
<PAGE>   
 
   
Steven R. Goodbarn* - Vice President and Chief Financial Officer
100 Fillmore Street
Denver, CO 80206-4928
    
   
     Vice President and Chief Financial Officer of Janus Aspen Series. Vice
     President of Finance, Treasurer and Chief Financial Officer of Janus
     Service, Janus Distributors and Janus Capital. Director of IDEX, Janus
     Service and Janus Distributors. Director, Treasurer and Vice President of
     Finance of Janus Capital International Ltd. Formerly (May 1992-January
     1996), Treasurer of Janus Investment Fund and Janus Aspen Series.
    
 
Glenn P. O'Flaherty* - Treasurer and Chief Accounting Officer
100 Fillmore Street
Denver, CO 80206-4928
     Treasurer and Chief Accounting Officer of Janus Aspen Series. Director of
     Fund Accounting of Janus Capital.
 
Kelley Abbott Howes* - Secretary
100 Fillmore Street
Denver, CO 80206-4928
   
     Secretary of Janus Aspen Series. Director and President of Janus
     Distributors. Associate Counsel of Janus Capital. Formerly (1990 to 1994),
     with The Boston Company Advisors, Inc., Boston Massachusetts (mutual fund
     administration services).
    
 
   
William D. Stewart# - Trustee
5330 Sterling Drive
Boulder, CO 80302
    
   
     Trustee of Janus Aspen Series. President of HPS Division of MKS
     Instruments, Boulder, Colorado (manufacturer of vacuum fittings and
     valves).
    
 
   
Gary O. Loo# - Trustee
102 N. Cascade Avenue, Suite 500
Colorado Springs, CO 80903
    
     Trustee of Janus Aspen Series. President and a Director of High Valley
     Group, Inc., Colorado Springs, Colorado (investments).
 
   
Dennis B. Mullen - Trustee
14103 Denver West Parkway
Golden, CO 80401
    
   
     Trustee of Janus Aspen Series. Chief Financial Officer - Boston Market
     Concepts, Boston Chicken, Inc., Golden, Colorado (restaurant chain).
     Formerly (1993-1997), President and Chief Executive Officer of BC
     Northwest, L.P., a franchise of Boston Chicken, Inc., Bellevue, Washington
     (restaurant chain).
    
 
- --------------------------------------------------------------------------------
*Interested person of the Trust and of Janus Capital.
#Member of the Trust's Executive Committee.
 
                                       18
<PAGE>   
 
Martin H. Waldinger - Trustee
4940 Sandshore Court
San Diego, CA 92130
   
     Trustee of Janus Aspen Series. Private Consultant. Formerly (1993 to 1996),
     Director of Run Technologies, Inc., a software development firm, San
     Carlos, California. Formerly (1989 to 1993), President and Chief Executive
     Officer of Bridgecliff Management Services, Campbell, California (a
     condominium association management company).
    
 
James T. Rothe - Trustee
102 South Tejon Street, Suite 1100
Colorado Springs, CO 80903
     Trustee of Janus Aspen Series. Professor of Business, University of
     Colorado, Colorado Springs, Colorado. Principal, Phillips-Smith Retail
     Group, Colorado Springs, Colorado (a venture capital firm). Formerly
     (1986-1994), Dean of the College of Business, University of Colorado,
     Colorado Springs, Colorado.
 
     The Trustees are responsible for major decisions relating to each Fund's
objective, policies and techniques. The Trustees also supervise the operation of
the Funds by their officers and review the investment decisions of the officers
although they do not actively participate on a regular basis in making such
decisions.
 
   
     The Trust's Executive Committee shall have and may exercise all the powers
and authority of the Trustees except for matters requiring action by all
Trustees pursuant to the Trust's Bylaws or Declaration of Trust, Massachusetts
Law or the 1940 Act.
    
 
   
     The Money Market Funds Committee, consisting of Messrs. Loo, Mullen and
Rothe, monitors the compliance with policies and procedures adopted particularly
for money market funds.
    
 
     The following table shows the aggregate compensation earned by and paid to
each Trustee by the Funds described in this SAI and all funds advised and
sponsored by Janus Capital (collectively, the "Janus Funds") for the periods
indicated. None of the Trustees receive any pension or retirement benefits from
the Funds or the Janus Funds.
 
   
<TABLE>
<CAPTION>
                           Aggregate Compensation      Total Compensation
                             from the Funds for     from the Janus Funds for
                             fiscal year ended         calendar year ended
                              October 31, 1997         December 31, 1997**
                              [To be filed by            [To be filed by
Name of Person, Position         Amendment]                Amendment]
- -----------------------------------------------------------------------------
<S>                        <C>                      <C>
Thomas H. Bailey,
  Chairman*                      $                         $
James P. Craig, III,
  Trustee*                       $                         $
William D. Stewart,
  Trustee                        $                         $
Gary O. Loo, Trustee             $                         $
Dennis B. Mullen, Trustee        $                         $
Martin H. Waldinger,
  Trustee                        $                         $
James T. Rothe, Trustee          $                         $
- -----------------------------------------------------------------------------
</TABLE>
    
 
 *An interested person of the Funds and of Janus Capital. Compensated by Janus
  Capital and not the Funds.
   
**As of December 31, 1997, Janus Funds consisted of two registered investment
  companies comprised of a total of 32 funds.
    
 
                                       19
<PAGE>   
 
                               PURCHASE OF SHARES
 
     As stated in the Prospectus, Janus Distributors is a distributor of the
Funds' shares. Shares are sold at the net asset value per share as determined at
the close of the regular trading session of the New York Stock Exchange (the
"NYSE" or the "Exchange") next occurring after a purchase order is received and
accepted by a Fund. A Fund's net asset value is calculated each day that both
the NYSE and the New York Federal Reserve Bank are open. As stated in the
Prospectus, the Funds each seek to maintain a stable net asset value per share
of $1.00. The Shareholder's Guide Section of the Prospectus contains detailed
information about the purchase of Shares.
 
                             REDEMPTIONS OF SHARES
 
     Redemptions, like purchases, may only be effected through the trust
accounts, cash management programs and similar programs of participating banks
and financial institutions. Shares normally will be redeemed for cash, although
each Fund retains the right to redeem its shares in kind under unusual
circumstances, in order to protect the interests of remaining shareholders, by
delivery of securities selected from its assets at its discretion. However, the
Funds are governed by Rule 18f-1 under the 1940 Act, which requires each Fund to
redeem shares solely in cash up to the lesser of $250,000 or 1% of the NAV of
that Fund during any 90-day period for any one shareholder. Should redemptions
by any shareholder exceed such limitation, a Fund will have the option of
redeeming the excess in cash or in kind. If shares are redeemed in kind, the
redeeming shareholder generally will incur brokerage costs in converting the
assets to cash. The method of valuing securities used to make redemptions in
kind will be the same as the method of valuing portfolio securities described
under "Shares of the Trust" and such valuation will be made as of the same time
the redemption price is determined.
 
     The right to require the Funds to redeem its shares may be suspended, or
the date of payment may be postponed, whenever (1) trading on the NYSE is
restricted, as determined by the SEC, or the NYSE is closed except for holidays
and weekends, (2) the SEC permits such suspension and so orders, or (3) an
emergency exists as determined by the SEC so that disposal of securities or
determination of NAV is not reasonably practicable.
 
                              SHAREHOLDER ACCOUNTS
 
     Detailed information about the general procedures for shareholder accounts
is set forth in the Prospectus. Applications to open accounts may be obtained by
calling or writing your Financial Institution.
 
                                       20
<PAGE>   
 
                            DIVIDENDS AND TAX STATUS
 
   
     Dividends representing substantially all of the net investment income and
any net realized gains on sales of securities are declared daily, Saturdays,
Sundays and holidays included, and distributed on the last business day of each
month. If a month begins on a Saturday, Sunday or holiday, dividends for those
days are declared at the end of the preceding month and distributed on the first
business day of the month. A shareholder may receive dividends via wire transfer
or may choose to have dividends automatically reinvested in a Fund's Shares. As
described in the Prospectus, Shares purchased by wire on a bank business day
will receive that day's dividend if the purchase is effected at or prior to 3:00
p.m. (New York time) for Janus Money Market Fund and Janus Government Money
Market Fund and 12:00 p.m. (New York time) for Janus Tax-Exempt Money Market
Fund. Otherwise, such Shares will begin to accrue dividends on the first bank
business day following receipt of the order. Requests for redemption of Shares
will be redeemed at the next determined net asset value. Redemption requests
made by wire that are received prior to 3:00 p.m. (New York time) for Janus
Money Market Fund and Janus Government Money Market Fund and 12:00 p.m. (New
York time) for Janus Tax-Exempt Money Market Fund will result in Shares being
redeemed that day. Proceeds of such a redemption will normally be sent to the
predesignated bank account on that day, but that day's dividend will not be
received. Closing times for purchase and redemption of Shares may be changed for
days in which the bond market or the NYSE close early.
    
 
     Distributions for all of the Funds (except Janus Tax-Exempt Money Market
Fund) are taxable income and are subject to federal income tax (except for
shareholders exempt from income tax), whether such distributions are received
via wire transfer or are reinvested in additional Shares. Full information
regarding the tax status of income dividends and any capital gains distributions
will be mailed to shareholders for tax purposes on or before January 31st of
each year. As described in detail in the Prospectus, Janus Tax-Exempt Money
Market Fund anticipates that substantially all income dividends it pays will be
exempt from federal income tax, although dividends attributable to interest on
taxable investments, together with distributions from any net realized short- or
long-term capital gains, are taxable.
 
     The Funds intend to qualify as regulated investment companies by satisfying
certain requirements prescribed by Subchapter M of the Internal Revenue Code of
1986.
 
   
     Some money market securities employ a trust or other similar structure to
modify the maturity, price characteristics, or quality of financial assets. For
example, put features can be used to modify the maturity of a security, or
interest rate adjustment features can be used to enhance price stability. If the
structure does not perform as intended, adverse tax or investment consequences
may result. Neither the Internal Revenue Service nor any other regulatory
authority has ruled definitively on certain legal issues presented by structured
securities. Future tax or other regulatory determinations could adversely affect
the value, liquidity, or tax treatment of the income received from these
securities or the nature and timing of distributions made by a Fund.
    
 
                                       21
<PAGE>   
 
                             PRINCIPAL SHAREHOLDERS
 
   
     [TO BE FILED BY AMENDMENT]
    
 
                           MISCELLANEOUS INFORMATION
 
   
     Each Fund is a series of the Trust, a Massachusetts Business Trust that was
created on February 11, 1986. The Trust is an open-end management investment
company registered under the 1940 Act. As of the date of this SAI, the Trust
consists of 19 separate series, three of which currently offer three classes of
Shares. The Funds were added to the Trust as separate series on December 9,
1994.
    
 
     Janus Capital reserves the right to the name "Janus." In the event that
Janus Capital does not continue to provide investment advice to the Funds, the
Funds must cease to use the name "Janus" as soon as reasonably practicable.
 
     Under Massachusetts law, shareholders of the Funds could, under certain
circumstances, be held liable for the obligations of their Fund. However, the
Agreement and Declaration of Trust (the "Declaration of Trust") disclaims
shareholder liability for acts or obligations of the Funds and requires that
notice of this disclaimer be given in each agreement, obligation or instrument
entered into or executed by the Funds or the Trustees. The Declaration of Trust
also provides for indemnification from the assets of the Funds for all losses
and expenses of any Fund shareholder held liable for the obligations of their
Fund. Thus, the risk of a shareholder incurring a financial loss on account of
its liability as a shareholder of one of the Funds is limited to circumstances
in which their Fund would be unable to meet its obligations. The possibility
that these circumstances would occur is remote. The Trustees intend to conduct
the operations of the Funds to avoid, to the extent possible, liability of
shareholders for liabilities of their Fund.
 
SHARES OF THE TRUST
     The Trust is authorized to issue an unlimited number of shares of
beneficial interest with a par value of one cent per share for each series of
the Trust. Shares of each Fund are fully paid and nonassessable when issued. All
shares of a Fund participate equally in dividends and other distributions by
such Fund, and in residual assets of that Fund in the event of liquidation.
Shares of each Fund have no preemptive, conversion or subscription rights.
 
     The Trust is authorized to issue multiple classes of shares for each Fund.
Currently, Janus Money Market Fund, Janus Government Money Market Fund and Janus
Tax-Exempt Money Market Fund each offer three classes of shares by separate
prospectuses. The Shares discussed in this SAI are offered only through
Financial Institutions that meet minimum investment requirements in connection
with trust accounts, cash management programs and similar programs provided to
their customers. A second class of shares, Institutional Shares, is offered to
individual, institutional and corporate clients and foundations and trusts
meeting certain minimum investment criteria. A third class of shares, Investor
Shares, is offered to the general public.
 
                                       22
<PAGE>   
 
VOTING RIGHTS
     The present Trustees were elected at a meeting of the Trust's shareholders
held on July 10, 1992, with the exception of Mr. Craig and Mr. Rothe who were
appointed by the Trustees as of June 30, 1995 and January 1, 1997, respectively.
Under the Declaration of Trust, each Trustee will continue in office until the
termination of the Trust or his earlier death, resignation, bankruptcy,
incapacity or removal. Vacancies will be filled by a majority of the remaining
Trustees, subject to the 1940 Act. Therefore, no annual or regular meetings of
shareholders normally will be held, unless otherwise required by the Declaration
of Trust or the 1940 Act. Subject to the foregoing, shareholders have the power
to vote to elect or remove Trustees, to terminate or reorganize their Fund, to
amend the Declaration of Trust, to bring certain derivative actions and on any
other matters on which a shareholder vote is required by the 1940 Act, the
Declaration of Trust, the Trust's Bylaws or the Trustees.
 
     Each share of each series of the Trust has one vote (and fractional votes
for fractional shares). Shares of all series of the Trust have noncumulative
voting rights, which means that the holders of more than 50% of the shares of
all series of the Trust voting for the election of Trustees can elect 100% of
the Trustees if they choose to do so and, in such event, the holders of the
remaining shares will not be able to elect any Trustees. Each series or class of
the Trust will vote separately only with respect to those matters that affect
only that series or class or if the interest of the series or class in the
matter differs from the interests of other series or classes of the Trust.
 
INDEPENDENT ACCOUNTANTS
     Price Waterhouse LLP, 950 Seventeenth Street, Suite 2500, Denver, Colorado
80202, independent accountants for the Funds, audit the Funds' annual financial
statements and prepare their tax returns.
 
REGISTRATION STATEMENT
   
     The Trust has filed with the SEC, Washington, D.C., a Registration
Statement under the Securities Act of 1933, as amended, with respect to the
securities to which this SAI relates. If further information is desired with
respect to the Funds or such securities, reference is made to the Registration
Statement and the exhibits filed as a part thereof.
    
 
                                       23
<PAGE>   
 
                              FINANCIAL STATEMENTS
 
   
     The following audited financial statements of the Institutional Shares and
Investor Shares of the Funds for the period ended October 31, 1997 are hereby
incorporated by reference to the Funds' Annual Report dated October 31, 1997. A
copy of such report accompanies this SAI.
    
 
DOCUMENTS INCORPORATED BY REFERENCE TO THE ANNUAL REPORT
 
   
     Schedules of Investments as of October 31, 1997
    
 
   
     Statements of Operations for the period ended October 31, 1997
    
 
   
     Statements of Assets and Liabilities as of October 31, 1997
    
 
   
     Statements of Changes in Net Assets for the periods ended October 31, 1997
     and October 31, 1996
    
 
   
     Financial Highlights for the fiscal period November 22, 1996 through
     October 31, 1997
    
 
   
     Notes to Financial Statements
    
 
   
     Report of Independent Accountants
    
 
     The portions of such Annual Report that are not specifically listed above
are not incorporated by reference into this SAI and are not part of the
Registration Statement.
 
                                       24
<PAGE>   
 
                                   APPENDIX A
 
DESCRIPTION OF SECURITIES RATINGS
 
MOODY'S AND STANDARD & POOR'S
 
MUNICIPAL AND CORPORATE BONDS AND MUNICIPAL LOANS
     The two highest ratings of Standard & Poor's Ratings Services ("S&P") for
municipal and corporate bonds are AAA and AA. Bonds rated AAA have the highest
rating assigned by S&P to a debt obligation. Capacity to pay interest and repay
principal is extremely strong. Bonds rated AA have a very strong capacity to pay
interest and repay principal and differ from the highest rated issues only in a
small degree. The AA rating may be modified by the addition of a plus (+) or
minus (-) sign to show relative standing within that rating category.
 
     The two highest ratings of Moody's Investors Service, Inc. ("Moody's") for
municipal and corporate bonds are Aaa and Aa. Bonds rated Aaa are judged by
Moody's to be of the best quality. Bonds rated Aa are judged to be of high
quality by all standards. Together with the Aaa group, they comprise what are
generally known as high-grade bonds. Moody's states that Aa bonds are rated
lower than the best bonds because margins of protection or other elements make
long-term risks appear somewhat larger than Aaa securities. The generic rating
Aa may be modified by the addition of the numerals 1, 2 or 3. The modifier 1
indicates that the security ranks in the higher end of the Aa rating category;
the modifier 2 indicates a mid-range ranking; and the modifier 3 indicates that
the issue ranks in the lower end of such rating category.
 
SHORT TERM MUNICIPAL LOANS
     S&P's highest rating for short-term municipal loans is SP-1. S&P states
that short-term municipal securities bearing the SP-1 designation have a strong
capacity to pay principal and interest. Those issues rated SP-1 which are
determined to possess a very strong capacity to pay debt service will be given a
plus (+) designation. Issues rated SP-2 have satisfactory capacity to pay
principal and interest with some vulnerability to adverse financial and economic
changes over the term of the notes.
 
     Moody's highest rating for short-term municipal loans is MIG-1/VMIG-1.
Moody's states that short-term municipal securities rated MIG-1/VMIG-1 are of
the best quality, enjoying strong protection from established cash flows of
funds for their servicing or from established and broad-based access to the
market for refinancing, or both. Loans bearing the MIG-2/VMIG-2 designation are
of high quality, with margins of protection ample although not so large as in
the MIG-1/VMIG-1 group.
 
OTHER SHORT-TERM DEBT SECURITIES
     Prime-1 and Prime-2 are the two highest ratings assigned by Moody's for
other short-term debt securities and commercial paper, and A-1 and A-2 are the
two highest ratings for commercial paper assigned by S&P. Moody's uses the
numbers 1, 2 and 3 to denote relative strength within its highest classification
of Prime, while S&P uses the numbers 1, 2 and 3 to denote relative strength
within its highest classification of A. Issuers rated Prime-1 by Moody's have a
superior ability for repayment of senior short-term debt obligations and have
many of the following characteristics: leading market positions in
well-established industries, high rates of return on funds employed,
 
                                       25
<PAGE>   
 
conservative capitalization structure with moderate reliance on debt and ample
asset protection, broad margins in earnings coverage of fixed financial charges
and high internal cash generation, and well established access to a range of
financial markets and assured sources of alternate liquidity. Issuers rated
Prime-2 by Moody's have a strong ability for repayment of senior short-term debt
obligations and display many of the same characteristics displayed by issuers
rated Prime-1, but to a lesser degree. Issuers rated A-1 by S&P carry a strong
degree of safety regarding timely repayment. Those issues determined to possess
extremely strong safety characteristics are denoted with a plus (+) designation.
Issuers rated A-2 by S&P carry a satisfactory degree of safety regarding timely
repayment.
 
   
FITCH
    
- --------------------------------------------------------------------------------
 
   
<TABLE>
<S>            <C>
F-1+           Exceptionally strong credit quality. Issues assigned this
               rating are regarded as having the strongest degree of
               assurance for timely payment.
F-1            Very strong credit quality. Issues assigned this rating
               reflect an assurance for timely payment only slightly
               less in degree than issues rated F-1+.
F-2            Good credit quality. Issues assigned this rating have a
               satisfactory degree of assurance for timely payments, but
               the margin of safety is not as great as the F-1+ and F-1
               ratings.
</TABLE>
    
 
DUFF & PHELPS INC.
- --------------------------------------------------------------------------------
 
<TABLE>
<S>            <C>
Duff 1+        Highest certainty of timely payment. Short-term
               liquidity, including internal operating factors and/or
               ready access to alternative sources of funds, is clearly
               outstanding, and safety is just below risk-free U.S.
               Treasury short- term obligations.
Duff 1         Very high certainty of timely payment. Liquidity factors
               are excellent and supported by good fundamental
               protection factors. Risk factors are minor.
Duff 1         High certainty of timely payment. Liquidity factors are
               strong and supported by good fundamental protection
               factors. Risk factors are very small.
Duff 2         Good certainty of timely payment. Liquidity factors and
               company fundamentals are sound. Although ongoing funding
               needs may enlarge total financing requirements, access to
               capital markets is good. Risk factors are small.
</TABLE>
 
THOMSON BANKWATCH, INC.
- --------------------------------------------------------------------------------
 
<TABLE>
<S>            <C>
TBW-1          The highest category; indicates a very high degree of
               likelihood that principal and interest will be paid on a
               timely basis.
TBW-2          The second highest category; while the degree of safety
               regarding timely repayment of principal and interest is
               strong, the relative degree of safety is not as high as
               for issues rated TBW-1.
TBW-3          The lowest investment grade category; indicates that
               while more susceptible to adverse developments (both
               internal and external) than obligations with higher
               ratings, capacity to service principal and interest in a
               timely fashion is considered adequate.
TBW-4          The lowest rating category; this rating is regarded as
               non-investment grade and therefore speculative.
</TABLE>
 
                                       26
<PAGE>   
 
IBCA, INC.
- --------------------------------------------------------------------------------
 
<TABLE>
<S>            <C>
A1+            Obligations supported by the highest capacity for timely
               repayment. Where issues possess a particularly strong
               credit feature, a rating of A1+ is assigned.
A2             Obligations supported by a good capacity for timely
               repayment.
A3             Obligations supported by a satisfactory capacity for
               timely repayment.
B              Obligations for which there is an uncertainty as to the
               capacity to ensure timely repayment.
C              Obligations for which there is a high risk of default or
               which are currently in default.
</TABLE>
 
- --------------------------------------------------------------------------------
 
                                       27
<PAGE>   
 
                                   APPENDIX B
 
DESCRIPTION OF MUNICIPAL SECURITIES
     MUNICIPAL NOTES generally are used to provide for short-term capital needs
and usually have maturities of one year or less. They include the following:
 
     1. PROJECT NOTES, which carry a U.S. government guarantee, are issued by
public bodies (called "local issuing agencies") created under the laws of a
state, territory, or U.S. possession. They have maturities that range up to one
year from the date of issuance. Project Notes are backed by an agreement between
the local issuing agency and the Federal Department of Housing and Urban
Development. These Notes provide financing for a wide range of financial
assistance programs for housing, redevelopment, and related needs (such as
low-income housing programs and renewal programs).
 
     2. TAX ANTICIPATION NOTES are issued to finance working capital needs of
municipalities. Generally, they are issued in anticipation of various seasonal
tax revenues, such as income, sales, use and business taxes, and are payable
from these specific future taxes.
 
     3. REVENUE ANTICIPATION NOTES are issued in expectation of receipt of other
types of revenues, such as Federal revenues available under the Federal Revenue
Sharing Programs.
 
     4. BOND ANTICIPATION NOTES are issued to provide interim financing until
long-term financing can be arranged. In most cases, the long-term bonds then
provide the money for the repayment of the Notes.
 
     5. CONSTRUCTION LOAN NOTES are sold to provide construction financing.
After successful completion and acceptance, many projects receive permanent
financing through the Federal Housing Administration under the Federal National
Mortgage Association ("Fannie Mae") or the Government National Mortgage
Association ("Ginnie Mae").
 
     6. TAX-EXEMPT COMMERCIAL PAPER is a short-term obligation with a stated
maturity of 365 days or less. It is issued by agencies of state and local
governments to finance seasonal working capital needs or as short-term financing
in anticipation of longer term financing.
 
     MUNICIPAL BONDS, which meet longer term capital needs and generally have
maturities of more than one year when issued, have three principal
classifications:
 
     1. GENERAL OBLIGATION BONDS are issued by such entities as states,
counties, cities, towns, and regional districts. The proceeds of these
obligations are used to fund a wide range of public projects, including
construction or improvement of schools, highways and roads, and water and sewer
systems. The basic security behind General Obligation Bonds is the issuer's
pledge of its full faith and credit and taxing power for the payment of
principal and interest. The taxes that can be levied for the payment of debt
service may be limited or unlimited as to the rate or amount of special
assessments.
 
                                       28
<PAGE>   
 
     2. REVENUE BONDS in recent years have come to include an increasingly wide
variety of types of municipal obligations. As with other kinds of municipal
obligations, the issuers of revenue bonds may consist of virtually any form of
state or local governmental entity, including states, state agencies, cities,
counties, authorities of various kinds, such as public housing or redevelopment
authorities, and special districts, such as water, sewer or sanitary districts.
Generally, revenue bonds are secured by the revenues or net revenues derived
from a particular facility, group of facilities, or, in some cases, the proceeds
of a special excise or other specific revenue source. Revenue bonds are issued
to finance a wide variety of capital projects including electric, gas, water and
sewer systems; highways, bridges, and tunnels; port and airport facilities;
colleges and universities; and hospitals. Many of these bonds provide additional
security in the form of a debt service reserve fund to be used to make principal
and interest payments. Various forms of credit enhancement, such as a bank
letter of credit or municipal bond insurance, may also be employed in revenue
bond issues. Housing authorities have a wide range of security, including
partially or fully insured mortgages, rent subsidized and/or collateralized
mortgages, and/or the net revenues from housing or other public projects. Some
authorities provide further security in the form of a state's ability (without
obligation) to make up deficiencies in the debt service reserve fund.
 
     In recent years, revenue bonds have been issued in large volumes for
projects that are privately owned and operated (see 3 below).
 
     3. PRIVATE ACTIVITY BONDS are considered municipal bonds if the interest
paid thereon is exempt from Federal income tax and are issued by or on behalf of
public authorities to raise money to finance various privately operated
facilities for business and manufacturing, housing and health. These bonds are
also used to finance public facilities such as airports, mass transit systems
and ports. The payment of the principal and interest on such bonds is dependent
solely on the ability of the facility's user to meet its financial obligations
and the pledge, if any, of real and personal property as security for such
payment.
 
     While, at one time, the pertinent provisions of the Internal Revenue Code
permitted private activity bonds to bear tax-exempt interest in connection with
virtually any type of commercial or industrial project (subject to various
restrictions as to authorized costs, size limitations, state per capita volume
restrictions, and other matters), the types of qualifying projects under the
Code have become increasingly limited, particularly since the enactment of the
Tax Reform Act of 1986. Under current provisions of the Code, tax-exempt
financing remains available, under prescribed conditions, for certain privately
owned and operated rental multi-family housing facilities, nonprofit hospital
and nursing home projects, airports, docks and wharves, mass commuting
facilities and solid waste disposal projects, among others, and for the
refunding (that is, the tax-exempt refinancing) of various kinds of other
private commercial projects originally financed with tax-exempt bonds. In future
years, the types of projects qualifying under the Code for tax-exempt financing
are expected to become increasingly limited.
 
     Because of terminology formerly used in the Internal Revenue Code,
virtually any form of private activity bond may still be referred to as an
"industrial development bond," but more and more frequently revenue bonds have
become classified according
 
                                       29
<PAGE>   
 
to the particular type of facility being financed, such as hospital revenue
bonds, nursing home revenue bonds, multi-family housing revenue bonds, single
family housing revenue bonds, industrial development revenue bonds, solid waste
resource recovery revenue bonds, and so on.
 
     OTHER MUNICIPAL OBLIGATIONS, incurred for a variety of financing purposes,
include: municipal leases, which may take the form of a lease or an installment
purchase or conditional sale contract, are issued by state and local governments
and authorities to acquire a wide variety of equipment and facilities such as
fire and sanitation vehicles, telecommunications equipment and other capital
assets. Municipal leases frequently have special risks not normally associated
with general obligation or revenue bonds. Leases and installment purchase or
conditional sale contracts (which normally provide for title to the leased asset
to pass eventually to the government issuer) have evolved as a means for
governmental issuers to acquire property and equipment without meeting the
constitutional and statutory requirements for the issuance of debt. The
debt-issuance limitations of many state constitutions and statutes are deemed to
be inapplicable because of the inclusion in many leases or contracts of
"non-appropriation" clauses that provide that the governmental issuer has no
obligation to make future payments under the lease or contract unless money is
appropriated for such purpose by the appropriate legislative body on a yearly or
other periodic basis. To reduce this risk, the Fund will only purchase municipal
leases subject to a non-appropriation clause when the payment of principal and
accrued interest is backed by an unconditional irrevocable letter of credit, or
guarantee of a bank or other entity that meets the criteria described in the
Prospectus.
 
     Tax-exempt bonds are also categorized according to whether the interest is
or is not includible in the calculation of alternative minimum taxes imposed on
individuals, according to whether the costs of acquiring or carrying the bonds
are or are not deductible in part by banks and other financial institutions, and
according to other criteria relevant for Federal income tax purposes. Due to the
increasing complexity of Internal Revenue Code and related requirements
governing the issuance of tax-exempt bonds, industry practice has uniformly
required, as a condition to the issuance of such bonds, but particularly for
revenue bonds, an opinion of nationally recognized bond counsel as to the
tax-exempt status of interest on the bonds.
 
                                       30
<PAGE>   
 
   
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<PAGE>


                             JANUS INVESTMENT FUND
                           PART C - OTHER INFORMATION

ITEM 24.  Financial Statements and Exhibits

     List all financial statements and exhibits filed as part of the
Registration Statement.

     (a)(1)    Financial Statements Included in the Prospectus:

               Financial Highlights for each of the following funds: Financial
               Highlights for all of the Funds will be filed by amendment on
               or before the effective date of this amendment.

     (a)(2)    Financial  Statements  Incorporated  by  Reference  into the
               Statement of Additional Information:
                  The Financial Statements for all of the Funds are included in
                  the Annual Report dated October 31, 1997, and will be
                  incorporated by reference into the respective Statement of
                  Additional Information by amendment which will be filed on or
                  before the effective date of this amendment.

     (b)       Exhibits:

               Exhibit 1 (a)  Agreement and Declaration of Trust dated
                              February 11, 1986 is incorporated herein by
                              reference to Exhibit 1(a) to Post-Effective
                              Amendment No. 79.

                         (b)  Certificate of Designation for Janus Growth and
                              Income Fund is incorporated herein by reference to
                              Exhibit 1(b) to Post-Effective Amendment No.
                              79.

                         (c)  Certificate of Designation for Janus Worldwide
                              Fund is incorporated herein by reference to
                              Exhibit 1(c) to Post-Effective Amendment No. 79.

                         (d)  Certificate of Designation for Janus Twenty Fund
                              is incorporated herein by reference to Exhibit
                              1(d) to Post-Effective Amendment No. 80.

                         (e)  Certificate of Designation for Janus Flexible
                              Income Fund is incorporated herein by reference to
                              Exhibit 1(e) to Post-Effective Amendment No.
                              80.

                         (f)  Certificate of Designation for Janus Intermediate
                              Government Securities Fund filed as Exhibit 1(f)
                              to Post-Effective Amendment No.
                              46 has been withdrawn.

                         (g)  Certificate of Designation for Janus Venture Fund
                              is incorporated herein by reference to Exhibit
                              1(g) to Post-Effective Amendment No. 80.

                                      C-1

<PAGE>


                         (h)  Certificate of Designation for Janus Enterprise
                              Fund is incorporated herein by reference to
                              Exhibit 1(h) to Post-Effective Amendment No. 80.

                         (i)  Certificate of Designation for Janus Balanced Fund
                              is incorporated herein by reference to Exhibit
                              1(i) to Post-Effective Amendment No. 80.

                         (j)  Certificate of Designation for Janus Short-Term
                              Bond Fund is incorporated herein by reference to
                              Exhibit 1(j) to Post-Effective Amendment No.
                              80.

                         (k)  Certificate of Designation for Janus Federal
                              Tax-Exempt Fund is incorporated herein by
                              reference to Exhibit 1(k) to Post-Effective
                              Amendment No. 81.

                         (l)  Certificate of Designation for Janus Mercury Fund
                              is incorporated herein by reference to Exhibit
                              1(l) to Post-Effective Amendment No. 81.

                         (m)  Certificate of Designation for Janus Overseas Fund
                              is incorporated herein by reference to Exhibit
                              1(m) to Post-Effective Amendment No. 81.

                         (n)  Form of Amendment to the Registrant's Agreement
                              and Declaration of Trust is incorporated herein by
                              reference to Exhibit 1(n) to Post-Effective
                              Amendment No. 81.

                         (o)  Form of Certificate of Designation for Janus Money
                              Market Fund, Janus Government Money Market Fund
                              and Janus Tax-Exempt Money Market Fund is
                              incorporated herein by reference to Exhibit 1(o)
                              to Post-Effective Amendment No. 81.

                         (p)  Form of Certificate of Designation for Janus
                              High-Yield Fund and Janus Olympus Fund is
                              incorporated herein by reference to Exhibit 1(p)
                              to Post-Effective Amendment No. 68.

                         (q)  Certificate of Designation for Janus Equity Income
                              Fund is incorporated herein by reference to
                              Exhibit 1(q) to Post-Effective Amendment No.
                              72.

                         (r)  Form of Certificate of Establishment and
                              Designation for Janus Special Situations Fund is
                              incorporated herein by reference to Exhibit 1(r)
                              to Post-Effective Amendment No. 75.

                                      C-2

<PAGE>


                         (s)  Form of Amendment to Registrant's Agreement and
                              Declaration of Trust is incorporated herein by
                              reference to Exhibit 1(s) to Post-Effective
                              Amendment No. 75.

                         (t)  Certificate  of  Establishment  and  Designation
                              for Janus  Global  Life  Sciences  Fund filed as
                              Exhibit 1(t) to Post-Effective  Amendment No. 82
                              is hereby withdrawn.

               Exhibit 2 (a)  Restated  Bylaws  are  incorporated   herein  by 
                              reference  to  Exhibit  2(a)  to  Post-Effective
                              Amendment No. 71.

                         (b)  First Amendment to the Bylaws is incorporated
                              herein by reference to Exhibit 2(b) to
                              Post-Effective Amendment No. 71.

               Exhibit 3      Not Applicable.

               Exhibit 4 (a) Specimen Stock Certificate for Janus Fund(1)
                              is incorporated herein by reference to Exhibit
                              4(b) to Post-Effective Amendment No. 79.

                        (b)   Specimen Stock Certificate for Janus Growth and
                              Income Fund is incorporated herein by reference to
                              Exhibit 4(b) to Post-Effective Amendment No.
                              79.

                        (c)   Specimen Stock Certificate for Janus Worldwide
                              Fund is incorporated herein by reference to
                              Exhibit 4(c) to Post-Effective Amendment No. 79.

                        (d)   Specimen Stock Certificate for Janus Twenty
                              Fund(1) is incorporated herein by reference to
                              Exhibit 4(d) to Post-Effective Amendment No. 80.

                        (e)   Specimen Stock Certificate for Janus Flexible
                              Income Fund(1) is incorporated herein by reference
                              to Exhibit 4(e) to Post-Effective
                              Amendment No. 80.

                        (f)   Specimen Stock Certificate for Janus Intermediate
                              Government Securities Fund(1) filed as Exhibit
                              4(f) to Post-Effective Amendment No. 46 has been
                              withdrawn.





- -------------------
(1) Outstanding certificates representing shares of predecessor entity to this
series of the Trust are deemed to represent shares of this series.

                                      C-3

<PAGE>


                        (g)   Specimen Stock Certificate for Janus Venture
                              Fund(1) is incorporated herein by reference to
                              Exhibit 4(g) to Post-Effective Amendment No. 80.

                        (h)   Specimen Stock Certificate for Janus Enterprise
                              Fund is incorporated herein by reference to
                              Exhibit 4(h) to Post-Effective Amendment No. 80.

                        (i)   Specimen Stock Certificate for Janus Balanced Fund
                              is incorporated herein by reference to Exhibit
                              4(i) to Post-Effective Amendment No. 80.

                        (j)   Specimen Stock Certificate for Janus Short-Term
                              Bond Fund is incorporated herein by reference to
                              Exhibit 4(j) to Post-Effective Amendment No.
                              80.

                        (k)   Specimen  Stock  Certificate  for Janus  Federal
                              Tax-Exempt  Fund  is   incorporated   herein  by
                              reference  to  Exhibit  4(k)  to  Post-Effective
                              Amendment No. 81.

                        (l)   Specimen Stock Certificate for Janus Mercury Fund
                              is incorporated herein by reference to Exhibit
                              4(l) to Post-Effective Amendment No. 81.

                        (m)   Specimen Stock Certificate for Janus Overseas Fund
                              is incorporated herein by reference to Exhibit
                              4(m) to Post-Effective Amendment No. 81.

                        (n)   Revised Specimen Stock Certificates for Janus
                              High-Yield Fund and Janus Olympus Fund are
                              incorporated herein by reference to Exhibit 4(n)
                              to Post-Effective Amendment No. 79.

                        (o)   Revised  Specimen  Stock  Certificate  for Janus
                              Equity  Income  Fund is  incorporated  herein by
                              reference  to  Exhibit 4(o)  to   Post-Effective
                              Amendment No. 79.

                        (p)   Revised  Specimen  Stock  Certificate  for Janus
                              Special  Situations Fund is incorporated  herein
                              by reference  to Exhibit 4(p) to  Post-Effective
                              Amendment No. 79.

                        (q)   Specimen  Stock  Certificate  for  Janus  Global
                              Life  Sciences  Fund  filed as  Exhibit  4(q) to
                              Post-Effective   Amendment   No.  82  is  hereby
                              withdrawn.

- -------------------
(1) Outstanding certificates representing shares of predecessor entity to this
series of the Trust are deemed to represent shares of this series.

                                      C-4

<PAGE>


               Exhibit 5 (a)  Investment Advisory Agreement for Janus Fund
                              dated July 1, 1997, is filed herein as Exhibit
                              5(a).

                         (b)  Investment Advisory Agreements for Janus Growth
                              and Income Fund and Janus Worldwide Fund dated
                              July 1, 1997, are filed herein as Exhibit 5(b).

                         (c)  Investment Advisory Agreements for Janus Twenty
                              Fund and Janus Venture Fund dated July 1, 1997,
                              are filed herein as Exhibit 5(c).

                         (d)  Investment Advisory Agreement for Janus Flexible
                              Income Fund dated July 1, 1997, is filed herein as
                              Exhibit 5(d).

                         (e)  Investment Advisory Agreements for Janus
                              Enterprise Fund, Janus Balanced Fund, and Janus
                              Short-Term Bond Fund dated July 1, 1997, are filed
                              herein as Exhibit 5(e).

                         (f)  Investment Advisory Agreements for Janus Federal
                              Tax-Exempt Fund and Janus Mercury Fund dated July
                              1, 1997, are filed herein as Exhibit 5(f).

                         (g)  Investment Advisory Agreement for Janus Overseas
                              Fund dated July 1, 1997, is filed herein as
                              Exhibit 5(g).

                         (h)  Investment Advisory Agreements for Janus Money
                              Market Fund, Janus Government Money Market Fund,
                              and Janus Tax-Exempt Money Market Fund dated July
                              1, 1997, are filed herein as Exhibit 5(h).

                         (i)  Investment Advisory Agreement for Janus High-Yield
                              Fund dated July 1, 1997, is filed herein as
                              Exhibit 5(i).

                         (j)  Investment Advisory Agreement for Janus Olympus
                              Fund dated July 1, 1997, is filed herein as
                              Exhibit 5(j).

                         (k)  Investment Advisory Agreement for Janus Equity
                              Income Fund dated July 1, 1997, is filed herein as
                              Exhibit 5(k).

                         (l)  Investment Advisory Agreement for Janus Special
                              Situations Fund dated July 1, 1997, is filed
                              herein as Exhibit 5(l).

                         (m)  Investment  Advisory  Agreement for Janus Global
                              Life  Sciences  Fund  filed as  Exhibit  5(m) to
                              Post-Effective   Amendment   No.  82  is  hereby
                              withdrawn.

                                      C-5

<PAGE>


               Exhibit 6      Distribution Agreement between Janus Investment
                              Fund and Janus Distributors, Inc., dated July 1,
                              1997, is filed herein as Exhibit 6.

               Exhibit 7      Not Applicable.

               Exhibit 8 (a)  Custodian Contract between Janus Investment
                              Fund and State Street Bank and Trust Company is
                              incorporated herein by reference to Exhibit 8(a)
                              to Post-Effective Amendment No. 79.

                         (b)  Amendment dated April 25, 1990 of State Street
                              Custodian Contract is incorporated herein by
                              reference to Exhibit 8(b) to Post-Effective
                              Amendment No. 79.

                         (c)  Letter Agreement dated February 1, 1991 regarding
                              State Street Custodian Contract is incorporated
                              herein by reference to Exhibit 8(c) to
                              Post-Effective Amendment No. 79.

                         (d)  Custodian Contract between Janus Investment Fund
                              and Investors Fiduciary Trust Company filed as
                              Exhibit 8(d) to Post-Effective Amendment No. 79
                              has been withdrawn.

                         (e)  Letter Agreement dated October 9, 1992 regarding
                              State Street Custodian Agreement is incorporated
                              herein by reference to Exhibit 8(e) to
                              Post-Effective Amendment No. 81.

                         (f)  Letter Agreement dated April 28, 1993 regarding
                              State Street Custodian Agreement is incorporated
                              herein by reference to Exhibit 8(f) to
                              Post-Effective Amendment No. 81.

                         (g)  Letter Agreement dated April 4, 1994 regarding
                              State Street Custodian Agreement is incorporated
                              herein by reference to Exhibit 8(g) to
                              Post-Effective Amendment No. 81.

                         (h)  Form of Custody Agreement between Janus Investment
                              Fund, on behalf of Janus Money Market Fund, Janus
                              Government Money Market Fund and Janus Tax-Exempt
                              Money Market Fund, and United Missouri Bank, N.A.
                              is incorporated herein by reference to Exhibit
                              8(h) to Post-Effective Amendment No. 81.

                         (i)  Letter Agreement dated December 12, 1995 regarding
                              State Street Custodian Contract is incorporated
                              herein by reference to Exhibit 8(i) to
                              Post-Effective Amendment No. 72.

                                      C-6

<PAGE>


                         (j)  Amendment dated October 11, 1995 of State Street
                              Custodian Contract is incorporated herein by
                              reference to Exhibit 8(j) to Post-Effective
                              Amendment No. 71.

                         (k)  Form of Amendment dated September 10, 1996 of
                              State Street Custodian Contract is incorporated
                              herein by reference to Exhibit 8(k) to
                              Post-Effective Amendment No. 75.

                         (l)  Letter Agreement dated September 10, 1996
                              regarding State Street Custodian Contract is
                              incorporated herein by reference to Exhibit 8(l)
                              to Post-Effective Amendment No. 75.

                         (m)  Form of Subcustodian Contract between United
                              Missouri Bank, N.A., and State Street Bank and
                              Trust Company is incorporated herein by reference
                              to Exhibit 8(m) to Post-Effective
                              Amendment No. 75.

                         (n)  Form of Letter Agreement dated September 9, 1997,
                              regarding State Street Custodian Contract is
                              incorporated herein by reference to Exhibit 8(n)
                              to Post-Effective Amendment No. 82.

               Exhibit 9 (a)  Transfer   Agency   Agreement   with   Investors
                              Fiduciary  Trust  Company  filed as Exhibit 9(a)
                              to  Post-Effective  Amendment  No.  79 is hereby
                              withdrawn.

                         (b)  Subagency   Agreement   between   Janus  Service
                              Corporation   and  Investors   Fiduciary   Trust
                              Company filed as Exhibit 9(b) to  Post-Effective
                              Amendment No. 79 is hereby withdrawn.

                         (c)  Form of Administration Agreement with Janus
                              Capital Corporation for Janus Money Market Fund,
                              Janus Government Money Market Fund and Janus
                              Tax-Exempt Money Market Fund is incorporated
                              herein by reference to Exhibit 9(c) to
                              Post-Effective Amendment No. 81.

                         (d)  Transfer Agency Agreement dated December 9, 1994
                              with Janus Service Corporation for Janus Money
                              Market Fund, Janus Government Money Market Fund
                              and Janus Tax-Exempt Money Market Fund filed as
                              Exhibit 9(d) to Post-Effective Amendment No. 64 is
                              withdrawn.

                         (e)  Transfer Agency Agreement dated September 27, 1995
                              with Janus Service Corporation for Janus Money
                              Market Fund, Janus Government Money Market Fund,
                              Janus Tax-

                                      C-7

<PAGE>


                              Exempt Money Market Fund, Janus
                              High-Yield Fund and Janus Olympus Fund is
                              incorporated herein by reference to Exhibit 9(e)
                              to Post-Effective Amendment No. 70.

                         (f)  Letter Agreement dated December 21, 1995 regarding
                              Janus Service Corporation Transfer Agency
                              Agreement is incorporated herein by reference to
                              Exhibit 9(f) to Post-Effective
                              Amendment No. 72.

                         (g)  Letter Agreement dated May 21, 1996 regarding
                              Janus Service Corporation Transfer Agency
                              Agreement is incorporated by reference to Exhibit
                              9(g) to Post-Effective Amendment No. 73.

                         (h)  Form of Amended Administration Agreement with
                              Janus Capital Corporation for Janus Money Market
                              Fund, Janus Government Money Market Fund, and
                              Janus Tax-Exempt Money Market Fund is incorporated
                              by reference to Exhibit 9(h) to Post-Effective
                              Amendment No. 77.

                         (i)  Letter Agreement dated September 10, 1996
                              regarding Janus Service Corporation Transfer
                              Agency Agreement is incorporated herein by
                              reference to Exhibit 9(i) to Post-Effective
                              Amendment No. 76.

                         (j)  Letter Agreement dated September 9, 1997,
                              regarding Janus Service Corporation Transfer
                              Agency Agreement is incorporated herein by
                              reference to Exhibit 9(j) to Post-Effective
                              Amendment No. 82.

               Exhibit 10(a)  Opinion and Consent of Messrs. Davis,
                              Graham & Stubbs with respect to shares of Janus
                              Fund is incorporated herein by reference to
                              Exhibit 10 (a) to Post-Effective Amendment No. 79.

                         (b)  Opinion and Consent of Fund Counsel with respect
                              to shares of Janus Growth and Income Fund and
                              Janus Worldwide Fund is incorporated herein by
                              reference to Exhibit 10(b) to Post-Effective
                              Amendment No. 79.

                         (c)  Opinion and Consent of Fund Counsel with respect
                              to shares of Janus Enterprise Fund, Janus Balanced
                              Fund and Janus Short-Term Bond Fund is
                              incorporated herein by reference to Exhibit 10(c)
                              to Post-Effective Amendment No.
                              80.

                         (d)  Opinion and Consent of Messrs. Sullivan and
                              Worcester with respect to shares of Janus Twenty
                              Fund is incorporated

                                      C-8

<PAGE>


                              herein by reference to Exhibit 10(d) to
                              Post-Effective Amendment No. 81.

                         (e)  Opinion and Consent of Messrs. Sullivan and
                              Worcester with respect to shares of Janus Venture
                              Fund is incorporated herein by reference to
                              Exhibit 10(e) to Post-Effective
                              Amendment No. 81.

                         (f)   Opinion and Consent of Messrs. Sullivan and
                              Worcester with respect to shares of Janus Flexible
                              Income Fund is incorporated herein by reference to
                              Exhibit 10(f) to Post-Effective Amendment No. 81.

                         (g)  Opinion and Consent of Messrs. Sullivan and
                              Worcester with respect to shares of Janus
                              Intermediate Government Securities Fund filed as
                              Exhibit 10(g) to Post-Effective Amendment No. 46
                              has been withdrawn.

                         (h)  Opinion and Consent of Fund Counsel with respect
                              to shares of Janus Federal Tax-Exempt Fund and
                              Janus Mercury Fund is incorporated herein by
                              reference to Exhibit 10(h) to Post-Effective
                              Amendment No. 81.

                         (i)  Opinion and Consent of Fund Counsel with respect
                              to shares of Janus Overseas Fund is incorporated
                              herein by reference to Exhibit 10(i) to
                              Post-Effective Amendment No.
                              81.

                         (j)  Opinion and Consent of Fund Counsel with respect
                              to shares of Janus Money Market Fund, Janus
                              Government Money Market Fund and Janus Tax-Exempt
                              Money Market Fund is incorporated herein by
                              reference to Exhibit 10(j) to Post-Effective
                              Amendment No. 81.

                         (k)  Opinion and Consent of Fund Counsel with respect
                              to Institutional Shares of Janus Money Market
                              Fund, Janus Government Money Market Fund and Janus
                              Tax-Exempt Money Market Fund is incorporated
                              herein by reference to Exhibit 10(k) to
                              Post-Effective Amendment No.
                              81.

                         (l)  Opinion and Consent of Fund Counsel with respect
                              to shares of Janus High-Yield Fund and Janus
                              Olympus Fund is incorporated herein by reference
                              to Exhibit 10(l) to Post-Effective Amendment No.
                              68.

                         (m)  Opinion and Consent of Fund Counsel with respect
                              to shares of Janus Equity Income Fund is
                              incorporated herein by reference to Exhibit 10(m)
                              to Post-Effective Amendment No.
                              72.

                                      C-9

<PAGE>


                         (n)  Opinion and Consent of Fund Counsel with respect
                              to shares of Janus Special Situations Fund is
                              incorporated herein by reference to Exhibit 10(n)
                              to Post-Effective Amendment No.
                              75.

                         (o)  Opinion and Consent of Fund Counsel with respect
                              to shares of Janus Money Market Fund, Janus
                              Government Money Market Fund, and Janus Tax-Exempt
                              Money Market Fund is incorporated herein by
                              reference to Exhibit 10(o) to Post-Effective
                              Amendment No. 76.

                         (p)  Opinion and Consent of Fund Counsel with respect
                              to shares of Janus Global Life Sciences Fund filed
                              as Exhibit 10(p) to Post-Effective Amendment No.
                              82 is hereby withdrawn.

               Exhibit 11     Consent of Price Waterhouse LLP is filed herein
                              as Exhibit 11.

               Exhibit 12     Not Applicable.

               Exhibit 13     Not Applicable.

               Exhibit 14(a)  Model    Individual     Retirement    Plan    is
                              incorporated  herein  by  reference  to  Exhibit
                              14(a) to Post-Effective Amendment No. 81.

                         (b)  Model Defined Contribution Retirement Plan is
                              incorporated herein by reference to Exhibit 14(b)
                              to Post-Effective Amendment No. 41.

                         (c)  Model Section 403(b)(7) Plan is incorporated
                              herein by reference to Exhibit 14(c) to
                              Post-Effective Amendment No. 81.

               Exhibit 15     Not Applicable.

               Exhibit 16(a) Computation of Total Return is incorporated
                              herein by reference as Exhibit 16(a) to
                              Post-Effective Amendment No. 80.

                         (b)  Computation of Current Yield and Effective Yield
                              is incorporated herein by reference to Exhibit
                              16(b) to Post-Effective Amendment No.
                              67.

               Exhibit 17     Powers of  Attorney  dated as of  May 20,  1997,
                              are   incorporated   herein  by   reference   to
                              Exhibit 17 to Post-Effective Amendment No. 81.

                                      C-10

<PAGE>


               Exhibit 18(a)  Form of plan  entered into by Janus Money Market
                              Fund,  Janus  Government  Money  Market Fund and
                              Janus  Tax-Exempt  Money Market Fund pursuant to
                              Rule   18f-3    setting   forth   the   separate
                              arrangement  and  expense   allocation  of  each
                              class  of such  Funds  filed  as  Exhibit 18  to
                              Post-Effective Amendment No. 66 is withdrawn.

                         (b)  Restated form of Rule 18f-3 Plan entered into by
                              Janus Money Market Fund, Janus Government Money
                              Market Fund and Janus Tax-Exempt Money Market Fund
                              is incorporated herein by reference to Exhibit
                              18(b) to Post-Effective Amendment
                              No. 69.

                         (c)  Amended and Restated form of Rule 18f-3 Plan
                              entered into by Janus Money Market Fund, Janus
                              Government Money Market Fund, and Janus Tax-Exempt
                              Money Market Fund is incorporated herein by
                              reference to Exhibit 18(c) to Post-Effective
                              Amendment No. 78.

               Exhibit 27     Financial Data Schedule for all of the Funds
                              (or classes thereof) to be filed by amendment on
                              or before the effective date of this amendment.


ITEM 25.  Persons Controlled by or Under Common Control with Registrant
          None
ITEM 26.  Number of Holders of Securities

          The number of record holders of shares of the Registrant as of
          November 18, 1997, was as follows:
                                                         Number of
          Title of Class                               Record Holders

          Janus Fund shares                            783,347
          Janus Growth and Income Fund shares          134,408
          Janus Worldwide Fund shares                  374,278
          Janus Overseas Fund shares                   124,267
          Janus Twenty Fund shares                     357,455
          Janus Flexible Income Fund shares             28,596
          Janus Venture Fund shares                     92,693
          Janus Enterprise Fund shares                  66,917
          Janus Balanced Fund shares                    26,208
          Janus Short-Term Bond Fund shares              4,865
          Janus Federal Tax-Exempt Fund shares           3,869
          Janus Mercury Fund shares                    187,402
          Janus Money Market Fund - Investor Shares     76,734
          Janus Money Market Fund - Institutional Shares    89
          Janus Money Market Fund - Service Shares           3
          Janus Government Money
               Market Fund - Investor Shares            10,542
          Janus Government Money
               Market Fund - Institutional Shares            9
          Janus Government Money

                                      C-11

<PAGE>


            
               Market Fund - Service Shares                  4
          Janus Tax-Exempt Money
               Market Fund - Investor Shares             5,310
          Janus Tax-Exempt Money
               Market Fund - Institutional Shares           15
          Janus Tax-Exempt Money
              Market Fund - Service Shares                   2
          Janus High-Yield Fund shares                   9,995
          Janus Olympus Fund shares                     50,630
          Janus Equity Income Fund shares                8,148
          Janus Special Situations Fund shares          31,622


ITEM 27.  Indemnification

     Article VIII of Janus Investment Fund's Agreement and Declaration of Trust
provides for indemnification of certain persons acting on behalf of the Funds.
In general, Trustees and officers will be indemnified against liability and
against all expenses of litigation incurred by them in connection with any
claim, action, suit or proceeding (or settlement of the same) in which they
become involved by virtue of their Fund office, unless their conduct is
determined to constitute willful misfeasance, bad faith, gross negligence or
reckless disregard of their duties, or unless it has been determined that they
have not acted in good faith in the reasonable belief that their actions were in
or not opposed to the best interests of the Funds. A determination that a person
covered by the indemnification provisions is entitled to indemnification may be
made by the court or other body before which the proceeding is brought, or by
either a vote of a majority of a quorum of Trustees who are neither "interested
persons" of the Trust nor parties to the proceeding or by an independent legal
counsel in a written opinion. The Funds also may advance money for these
expenses, provided that the Trustee or officer undertakes to repay the Funds if
his conduct is later determined to preclude indemnification, and that either he
provide security for the undertaking, the Trust be insured against losses
resulting from lawful advances or a majority of a quorum of disinterested
Trustees, or independent counsel in a written opinion, determines that he
ultimately will be found to be entitled to indemnification. The Trust also
maintains a liability insurance policy covering its Trustees and officers.


ITEM 28.  Business and Other Connections of Investment Adviser

     The only business of Janus Capital Corporation is to serve as the
investment adviser of the Registrant and as investment adviser or subadviser to
several other mutual funds and private and retirement accounts. Business
backgrounds of the principal executive officers and directors of the adviser
that also hold positions with the Registrant are included under "Officers and
Trustees" in the currently effective Statements of Additional Information of the
Registrant. The remaining principal executive officers of the investment adviser
and their positions with the adviser and affiliated entities are: Mark B.
Whiston, Vice President and Chief Marketing Officer of Janus Capital
Corporation, Director and President of Janus Capital International Ltd.;
Marjorie G. Hurd, Vice President and Chief Operations Officer of Janus Capital
Corporation, Director and President of Janus Service Corporation; and Stephen L.
Stieneker, Assistant General Counsel, Chief Compliance Officer and Vice
President of Compliance of Janus Capital Corporation. Mr. Michael E. Herman, a
director of Janus Capital Corporation, is Chairman of the Finance Committee
(1990 to present) of Ewing Marion Kauffman Foundation, 4900 Oak, Kansas City,
Missouri 64112. Mr. Michael N. Stolper, a director of Janus Capital Corporation,
is 

                                      C-12

<PAGE>


President of Stolper & Company, Inc., 525 "B" Street, Suite 1080, San Diego,
California 92101, an investment performance consultant. Mr. Thomas A. McDonnell,
a director of Janus Capital Corporation, is President, Chief Executive Officer
and a Director of DST Systems, Inc., 1055 Broadway, 9th Floor, Kansas City,
Missouri 64105, provider of data processing and recordkeeping services for
various mutual funds, and is Executive Vice President and a director of Kansas
City Southern Industries, Inc., 114 W. 11th Street, Kansas City, Missouri 64105,
a publicly traded holding company whose primary subsidiaries are engaged in
transportation, information processing and financial services. Mr. Landon H.
Rowland, a director of Janus Capital Corporation, is President and Chief
Executive Officer of Kansas City Southern Industries, Inc.


ITEM 29.  Principal Underwriters

          (a)     Janus Distributors,  Inc. ("Janus Distributors") serves as a
                  principal  underwriter for the Registrant and the Retirement
                  Shares of Janus Aspen Series only.

          (b)     The  principal   business  address,   positions  with  Janus
                  Distributors  and positions with Registrant of Kelley Abbott
                  Howes and  Steven R.  Goodbarn,  officers  and  directors of
                  Janus  Distributors,   are  described  under  "Officers  and
                  Trustees"  in  the  Statement  of   Additional   Information
                  included  in  this  Registration  Statement.  The  remaining
                  principal   executive  officer  of  Janus   Distributors  is
                  Jennifer A.  Davis,  Secretary.  Ms. Davis does not hold any
                  positions  with  the   Registrant.   Ms.  Davis'   principal
                  business  address is 100 Fillmore Street,  Denver,  Colorado
                  80206-4928.

          (c)     Not applicable.


ITEM 30.  Location of Accounts and Records

     The accounts, books and other documents required to be maintained by
Section 31(a) of the Investment Company Act of 1940 and the rules promulgated
thereunder are maintained by Janus Capital Corporation and Janus Service
Corporation, both of which are located at 100 Fillmore Street, Denver, Colorado
80206-4928, and by State Street Bank and Trust Company, P.O. Box 351, Boston,
Massachusetts 02101, and United Missouri Bank, P.O. Box 419226, Kansas City,
Missouri 64141-6226.


ITEM 31.  Management Services

      The Registrant has no management-related service contract which is not
discussed in Part A or Part B of this form.

                                      C-13

<PAGE>


ITEM 32.  Undertakings

          (a)  Not applicable.

          (b)  Not applicable.

          (c)  The Registrant undertakes to furnish each person to whom a
               prospectus is delivered with a copy of the Registrant's latest
               annual report to shareholders, upon request and without
               charge.

                                      C-14

<PAGE>


                                   SIGNATURES


     Pursuant to the requirements of the Securities Act of 1933 and the
Investment Company Act of 1940, the Registrant has duly caused this Amendment to
its Registration Statement to be signed on its behalf by the undersigned,
thereto duly authorized, in the City of Denver, and State of Colorado, on the
15th day of December, 1997.

                                    JANUS INVESTMENT FUND


                                    By:  /s/ Thomas H. Bailey
                                         Thomas H. Bailey, President

     Janus Investment Fund is organized under the Agreement and Declaration of
Trust of the Registrant dated February 11, 1986, a copy of which is on file with
the Secretary of State of The Commonwealth of Massachusetts. The obligations of
the Registrant hereunder are not binding upon any of the Trustees, shareholders,
nominees, officers, agents or employees of the Registrant personally, but bind
only the trust property of the Registrant, as provided in the Agreement and
Declaration of Trust of the Registrant. The execution of this Amendment to the
Registration Statement has been authorized by the Trustees of the Registrant and
this Amendment to the Registration Statement has been signed by an authorized
officer of the Registrant, acting as such, and neither such authorization by
such Trustees nor such execution by such officer shall be deemed to have been
made by any of them personally, but shall bind only the trust property of the
Registrant as provided in its Declaration of Trust.

     Pursuant to the requirements of the Securities Act of 1933, this Amendment
to the Registration Statement has been signed below by the following persons in
the capacities and on the dates indicated.

Signature                     Title                         Date


/s/ Thomas H. Bailey          President                     December 15, 1997
Thomas H. Bailey              (Principal Executive
                              Officer) and Trustee

/s/ Steven R. Goodbarn        Vice President and            December 15, 1997
Steven R. Goodbarn            Chief Financial Officer
                              (Principal Financial
                              Officer)

/s/ Glenn P. O'Flaherty       Treasurer and Chief           December 15, 1997
Glenn P. O'Flaherty           Accounting Officer
                              (Principal Accounting
                              Officer)


<PAGE>


/s/ James P. Craig, III        Trustee                      December 15, 1997
James P. Craig, III

Gary O. Loo*                   Trustee                      December 15, 1997 
Gary O. Loo

Dennis B. Mullen*              Trustee                      December 15, 1997
Dennis B. Mullen

James T. Rothe*                Trustee                      December 15, 1997
James T. Rothe

William D. Stewart*            Trustee                      December 15, 1997
William D. Stewart

Martin H. Waldinger*           Trustee                      December 15, 1997
Martin H. Waldinger



/s/ Steven R. Goodbarn
*By   Steven R. Goodbarn
      Attorney-in-Fact


<PAGE>


                             INDEX OF EXHIBITS

      Exhibit 5(a)           Investment  Advisory  Agreement  for Janus
                             Fund

      Exhibit 5(b)           Investment  Advisory  Agreements for Janus
                             Growth and Income Fund and Janus Worldwide Fund

      Exhibit 5(c)           Investment  Advisory  Agreements for Janus
                             Twenty Fund and Janus Venture Fund

      Exhibit 5(d)           Investment  Advisory  Agreement  for Janus
                             Flexible Income Fund

      Exhibit 5(e)           Investment  Advisory  Agreements for Janus
                             Enterprise  Fund, Janus Balanced Fund, and Janus
                             Short-Term Bond Fund

      Exhibit 5(f)           Investment  Advisory  Agreements for Janus
                             Federal Tax-Exempt Fund and Janus Mercury Fund

      Exhibit 5(g)           Investment  Advisory  Agreement  for Janus
                             Overseas Fund

      Exhibit 5(h)           Investment  Advisory  Agreements for Janus
                             Money  Market  Fund,   Janus   Government  Money
                             Market Fund, and Janus  Tax-Exempt  Money Market
                             Fund

      Exhibit 5(i)           Investment  Advisory  Agreement  for Janus
                             High-Yield Fund

      Exhibit 5(j)           Investment  Advisory  Agreement  for Janus
                             Olympus Fund

      Exhibit 5(k)           Investment  Advisory  Agreement  for Janus
                             Equity Income Fund

      Exhibit 5(l)           Investment  Advisory  Agreement  for Janus
                             Special Situations Fund

      Exhibit 6              Distribution Agreement

      Exhibit 11             Consent of Price Waterhouse










                                                                 EXHIBIT 5(a)


                             JANUS INVESTMENT FUND

                         INVESTMENT ADVISORY AGREEMENT

                                   JANUS FUND


     THIS INVESTMENT ADVISORY AGREEMENT (the "Agreement") is made this 1st
day of July, 1997, between JANUS INVESTMENT FUND, a Massachusetts business trust
(the "Trust"), and JANUS CAPITAL CORPORATION, a Colorado corporation ("JCC").

                              W I T N E S S E T H:

     WHEREAS, the Trust is registered as an open-end management investment
company under the Investment Company Act of 1940, as amended (the "1940 Act"),
and has registered its shares for public offering under the Securities Act of
1933, as amended (the "1933 Act"); and

     WHEREAS, the Trust is authorized to create separate funds, each with
its own separate investment portfolio of which the beneficial interests are
represented by a separate series of shares; one of such funds created by the
Trust being designated as the Janus Fund (the "Fund"); and

     WHEREAS, the Trust and JCC deem it mutually advantageous that JCC
should assist the Board of Trustees and officers of the Trust in the management
of the securities portfolio of the Fund.

     NOW, THEREFORE, the parties agree as follows:

     1.   Investment Advisory Services. JCC shall furnish continuous advice
and recommendations to the Fund as to the acquisition, holding, or disposition
of any or all of the securities or other assets which the Fund may own or
contemplate acquiring from time to time. JCC shall give due consideration to the
investment policies and restrictions and the other statements concerning the
Fund in the Trust's declaration of trust, bylaws, and registration statements
under the 1940 Act and the 1933 Act, and to the provisions of the Internal
Revenue Code, as amended from time to time, applicable to the Fund as a
regulated investment company. In addition, JCC shall cause its officers to
attend meetings and furnish oral or written reports, as the Trust may reasonably
require, in order to keep the Board of Trustees and appropriate officers of the
Trust fully informed as to the condition of the investment portfolio of the
Fund, the investment recommendations of JCC, and the investment considerations
which have given rise to those recommendations. JCC shall supervise the purchase
and sale of securities as directed by the appropriate officers of the Trust.

     2. Other Services. JCC is hereby authorized (to the extent the Trust
has not otherwise contracted) but not obligated (to the extent it so notifies
the Board of Trustees at least 60 days in advance), to perform (or arrange for
the performance by affiliates of) the management and administrative services
necessary for the operation of the Fund. JCC is specifically authorized, on


                                     - 1 -

<PAGE>


behalf of the Trust, to conduct relations with custodians, depositories,
transfer and pricing agents, accountants, attorneys, underwriters, brokers and
dealers, corporate fiduciaries, insurers, banks and such other persons in any
such other capacity deemed by JCC to be necessary or desirable. JCC shall
generally monitor and report to Fund officers the Fund's compliance with
investment policies and restrictions as set forth in the currently effective
prospectus and statement of additional information relating to the shares of the
Fund under the Securities Act of 1933, as amended. JCC shall make reports to the
Trust's Board of Trustees of its performance of services hereunder upon request
therefor and furnish advice and recommendations with respect to such other
aspects of the business and affairs of the Fund as it shall determine to be
desirable. JCC is also authorized, subject to review by the Board of Trustees,
to furnish such other services as the Adviser shall from time to time determine
to be necessary or useful to perform the services contemplated by this
Agreement.

     3.   Obligations of Trust. The Trust shall have the following obligations
under this Agreement:

          (a)  to keep JCC continuously and fully informed as to the
               composition of its investment portfolio and the
               nature of all of its assets and liabilities from time
               to time;

          (b)  to furnish JCC with a certified copy of any financial
               statement or report prepared for it by certified or
               independent public accountants and with copies of any
               financial statements or reports made to its
               shareholders or to any governmental body or
               securities exchange;

          (c)  to furnish JCC with any further materials or
               information which JCC may reasonably request to
               enable it to perform its function under this
               Agreement; and

          (d)  to compensate JCC for its services and reimburse JCC
               for its expenses incurred hereunder in accordance
               with the provisions hereof.

     4.   Compensation. The Trust shall pay to JCC for its investment advisory
services a fee, calculated and payable for each day that this Agreement is in
effect, of 1/365 of 0.75% of the first $300,000,000 of the daily closing net
asset value of the Fund, plus 1/365 of 0.70% of the next $200,000,000 of the
daily closing net asset value of the Fund, plus 1/365 of 0.65% of the daily
closing net asset value of the Fund in excess of $500,000,000. The fee shall be
paid monthly.

     5.   Expenses Borne by JCC. In addition to the expenses which JCC may
incur in the performance of its investment advisory functions under this
Agreement, and the expenses which it may expressly undertake to incur and pay
under other agreements with the Trust or otherwise, JCC shall incur and pay the
following expenses relating to the Fund's operations without reimbursement from
the Fund:


                                     - 2 -

<PAGE>


          (a)  Reasonable compensation, fees and related expenses of
               the Trust's officers and its Trustees (the
               "Trustees"), except for such Trustees who are not
               interested persons of JCC;

          (b)  Rental of offices of the Trust; and

          (c)  All expenses of promoting the sale of shares of the Fund, other
               than expenses incurred in complying with federal and state laws
               and the law of any foreign country or territory or other 
               jurisdiction applicable to the issue, offer or sale
               of shares of the Fund including without limitation registration 
               fees and costs, the costs of preparing the Fund's registration
               statement and amendments thereto, and the costs and expenses of
               preparing, printing, and mailing prospectuses (and statements of
               additional information) to persons other than shareholders of
               the Fund.

     6.   Expenses Borne by the Trust. The Trust assumes and shall pay all
expenses incidental to its organization, operations and business not
specifically assumed or agreed to be paid by JCC pursuant to Sections 2 and 5
hereof, including, but not limited to, investment adviser fees; any
compensation, fees, or reimbursements which the Trust pays to its Trustees who
are not interested persons of JCC; compensation of the Fund's custodian,
transfer agent, registrar and dividend disbursing agent; legal, accounting,
audit and printing expenses; administrative, clerical, recordkeeping and
bookkeeping expenses; brokerage commissions and all other expenses in connection
with execution of portfolio transactions (including any appropriate commissions
paid to JCC or its affiliates for effecting exchange listed, over-the-counter or
other securities transactions); interest; all federal, state and local taxes
(including stamp, excise, income and franchise taxes); costs of stock
certificates and expenses of delivering such certificates to the purchaser
thereof; expenses of local representation in Massachusetts; expenses of
shareholders' meetings and of preparing, printing and distributing proxy
statements, notices, and reports to shareholders; expenses of preparing and
filing reports and tax returns with federal and state regulatory authorities;
all expenses incurred in complying with all federal and state laws and the laws
of any foreign country applicable to the issue, offer, or sale of shares of the
Fund, including, but not limited to, all costs involved in the registration or
qualification of shares of the Fund for sale in any jurisdiction, the costs of
portfolio pricing services and systems for compliance with blue sky laws, and
all costs involved in preparing, printing and mailing prospectuses and
statements of additional information of the Fund; and all fees, dues and other
expenses incurred by the Trust in connection with the membership of the Trust in
any trade association or other investment company organization. To the extent
that JCC shall perform any of the above described administrative and clerical
functions, including transfer agency, registry, dividend disbursing,
recordkeeping, bookkeeping, accounting and blue sky monitoring and registration
functions, and the preparation of reports and returns, the Trust shall pay to
JCC compensation for, or reimburse JCC for its expenses incurred in connection
with, such services as JCC and the Trust shall agree from time to time, any
other provision of this Agreement notwithstanding.


                                     - 3 -

<PAGE>


     7.   Treatment of Investment Advice. The Trust shall treat the investment
advice and recommendations of JCC as being advisory only, and shall retain full
control over its own investment policies. However, the Trustees may delegate to
the appropriate officers of the Trust, or to a committee of the Trustees, the
power to authorize purchases, sales or other actions affecting the portfolio of
the Fund in the interim between meetings of the Trustees.

     8.   Brokerage Commissions. For purposes of this Agreement, brokerage
commissions paid by the Fund upon the purchase or sale of its portfolio
securities shall be considered a cost of securities of the Fund and shall be
paid by the Fund. JCC is authorized and directed to place Fund portfolio
transactions only with brokers and dealers who render satisfactory service in
the execution of orders at the most favorable prices and at reasonable
commission rates, provided, however, that JCC may pay a broker or dealer an
amount of commission for effecting a securities transaction in excess of the
amount of commission another broker or dealer would have charged for effecting
that transaction if JCC determines in good faith that such amount of commission
was reasonable in relation to the value of the brokerage and research services
provided by such broker or dealer viewed in terms of either that particular
transaction or the overall responsibilities of JCC. JCC is also authorized to
consider sales of Trust shares as a factor in selecting broker-dealers to
execute Fund portfolio transactions. In placing portfolio business with such
broker-dealers, JCC shall seek the best execution of each transaction. Subject
to the terms of this Agreement and the applicable requirements and provisions of
the law, including the Investment Company Act of 1940 and the Securities
Exchange Act of 1934, as amended, and in the event that JCC or an affiliate is
registered as a broker-dealer, JCC may select a broker or dealer with which it
or the Fund is affiliated. JCC or such affiliated broker-dealer may effect or
execute Fund portfolio transactions, whether on a securities exchange or in the
over-the-counter market, and receive separate compensation from the Fund
therefor. Notwithstanding the foregoing, the Trust shall retain the right to
direct the placement of all portfolio transactions, and the Trustees of the
Trust may establish policies or guidelines to be followed by JCC in placing
portfolio transactions for the Trust pursuant to the foregoing provisions. JCC
shall report on the placement of portfolio transactions in the prior fiscal
quarter at each quarterly meeting of such Trustees.

     9.   Termination. This Agreement may be terminated at any time, without
penalty, by the Board of Trustees of the Trust, or by the shareholders of the
Trust acting by vote of at least a majority of its outstanding voting
securities, provided in either case that sixty (60) days advance written notice
of termination be given to JCC at its principal place of business. This
Agreement may be terminated by JCC at any time, without penalty, by giving sixty
(60) days advance written notice of termination to the Trust, addressed to its
principal place of business. The Trust agrees that, consistent with the terms of
the Trust's Declaration of Trust, the Trust shall cease to use the name "Janus"
in connection with the Fund as soon as reasonably practicable following any
termination of this Agreement if JCC does not continue to provide investment
advice to the Fund after such termination.

     10.  Assignment. This Agreement shall terminate automatically in the
event of any assignment of this Agreement.


                                     - 4 -

<PAGE>


     11.  Term. This Agreement shall continue in effect until July 1, 1998,
unless sooner terminated in accordance with its terms, and shall continue in
effect from year to year thereafter only so long as such continuance is
specifically approved at least annually by the vote of a majority of the
Trustees of the Trust who are not parties hereto or interested persons of any
such party, cast in person at a meeting called for the purpose of voting on the
approval of the terms of such renewal, and by either the Board of Trustees of
the Trust or the affirmative vote of a majority of the outstanding voting
securities of the Trust. The annual approvals provided for herein shall be
effective to continue this Agreement from year to year if given within a period
beginning not more than sixty (60) days prior to July 1 of each applicable year,
notwithstanding the fact that more than three hundred sixty-five (365) days may
have elapsed since the date on which such approval was last given.

     12.  Amendments. This Agreement may be amended by the parties only if
such amendment is specifically approved (i) by a majority of the Trustees,
including a majority of the Trustees who are not interested persons (as that
phrase is defined in Section 2(a)(19) of the 1940 Act) of JCC and, if required
by applicable law, (ii) by the affirmative vote of a majority of the outstanding
voting securities of the Fund (as that phrase is defined in Section 2(a)(42) of
the 1940 Act).

     13.  Other Series. The Trustees shall determine the basis for making an
appropriate allocation of the Trust's expenses (other than those directly
attributable to the Fund) between the Fund and the other series of the Trust.

     14.  Limitation of Personal Liability. All the parties hereto
acknowledge and agree that all liabilities of the Trust arising, directly or
indirectly, under this Agreement, of any and every nature whatsoever, shall be
satisfied solely out of the assets of the Fund and that no Trustee, officer or
holder of shares of beneficial interest of the Trust shall be personally liable
for any of the foregoing liabilities. The Trust's Declaration of Trust, as
amended from time to time, is on file in the Office of the Secretary of State of
the Commonwealth of Massachusetts. Such Declaration of Trust describes in detail
the respective responsibilities and limitations on liability of the Trustees,
officers and holders of shares of beneficial interest of the Trust.

     15.  Limitation of Liability of JCC. JCC shall not be liable for any
error of judgment or mistake of law or for any loss arising out of any
investment or for any act or omission taken with respect to the Trust, except
for willful misfeasance, bad faith or gross negligence in the performance of its
duties, or by reason of reckless disregard of its obligations and duties
hereunder and except to the extent otherwise provided by law. As used in this
Section 15, "JCC" shall include any affiliate of JCC performing services for the
Trust contemplated hereunder and directors, officers and employees of JCC and
such affiliates.

     16.  Activities of JCC. The services of JCC to the Trust hereunder are
not to be deemed to be exclusive, and JCC and its affiliates are free to render
services to other parties. It is understood that trustees, officers and
shareholders of the Trust are or may become interested in JCC as directors,


                                     - 5 -

<PAGE>


officers and shareholders of JCC, that directors, officers, employees and
shareholders of JCC are or may become similarly interested in the Trust, and
that JCC may become interested in the Trust as a shareholder or otherwise.

     17.  Certain Definitions. The terms "vote of a majority of the
outstanding voting securities", "assignment" and "interested persons" when used
herein, shall have the respective meanings specified in the 1940 Act, as now in
effect or hereafter amended, and the rules and regulations thereunder, subject
to such orders, exemptions and interpretations as may be issued by the
Securities and Exchange Commission under said Act and as may be then in effect.

     IN WITNESS WHEREOF, the parties have caused their duly authorized
officers to execute this Investment Advisory Agreement as of this 1st day of
July, 1997.


                                        JANUS CAPITAL CORPORATION



                                        By: /s/ Steven R. Goodbarn
                                        Steven R. Goodbarn, Vice President


                                        JANUS INVESTMENT FUND



                                        By: /s/ Thomas H. Bailey
                                            Thomas H. Bailey, President


                                     - 6 -



                                                            EXHIBIT 5(b)


                             JANUS INVESTMENT FUND

                         INVESTMENT ADVISORY AGREEMENT

                          JANUS GROWTH AND INCOME FUND


     THIS INVESTMENT ADVISORY AGREEMENT (the "Agreement") is made this 1st
day of July, 1997, between JANUS INVESTMENT FUND, a Massachusetts business trust
(the "Trust"), and JANUS CAPITAL CORPORATION, a Colorado corporation ("JCC").

                              W I T N E S S E T H:

     WHEREAS, the Trust is registered as an open-end management investment
company under the Investment Company Act of 1940, as amended (the "1940 Act"),
and has registered its shares for public offering under the Securities Act of
1933, as amended (the "1933 Act"); and

     WHEREAS, the Trust is authorized to create separate funds, each with
its own separate investment portfolio of which the beneficial interests are
represented by a separate series of shares; one of such funds created by the
Trust being designated as the Janus Growth and Income Fund (the "Fund"); and

     WHEREAS, the Trust and JCC deem it mutually advantageous that JCC
should assist the Board of Trustees and officers of the Trust in the management
of the securities portfolio of the Fund.

     NOW, THEREFORE, the parties agree as follows:

     1.   Investment Advisory Services. JCC shall furnish continuous advice
and recommendations to the Fund as to the acquisition, holding, or disposition
of any or all of the securities or other assets which the Fund may own or
contemplate acquiring from time to time. JCC shall give due consideration to the
investment policies and restrictions and the other statements concerning the
Fund in the Trust's declaration of trust, bylaws, and registration statements
under the 1940 Act and the 1933 Act, and to the provisions of the Internal
Revenue Code, as amended from time to time, applicable to the Fund as a
regulated investment company. In addition, JCC shall cause its officers to
attend meetings and furnish oral or written reports, as the Trust may reasonably
require, in order to keep the Board of Trustees and appropriate officers of the
Trust fully informed as to the condition of the investment portfolio of the
Fund, the investment recommendations of JCC, and the investment considerations
which have given rise to those recommendations. JCC shall supervise the purchase
and sale of securities as directed by the appropriate officers of the Trust.

     2.   Other Services. JCC is hereby authorized (to the extent the Trust
has not otherwise contracted) but not obligated (to the extent it so notifies
the Board of Trustees at least 60 days in advance), to perform (or arrange for
the performance by affiliates of) the management and

                                     - 1 -

<PAGE>


administrative services necessary for the operation of the Fund. JCC is
specifically authorized, on behalf of the Trust, to conduct relations with
custodians, depositories, transfer and pricing agents, accountants, attorneys,
underwriters, brokers and dealers, corporate fiduciaries, insurers, banks and
such other persons in any such other capacity deemed by JCC to be necessary or
desirable. JCC shall generally monitor and report to Fund officers the Fund's
compliance with investment policies and restrictions as set forth in the
currently effective prospectus and statement of additional information relating
to the shares of the Fund under the Securities Act of 1933, as amended. JCC
shall make reports to the Trust's Board of Trustees of its performance of
services hereunder upon request therefor and furnish advice and recommendations
with respect to such other aspects of the business and affairs of the Fund as it
shall determine to be desirable. JCC is also authorized, subject to review by
the Board of Trustees, to furnish such other services as the Adviser shall from
time to time determine to be necessary or useful to perform the services
contemplated by this Agreement.

     3.   Obligations of Trust. The Trust shall have the following obligations
under this Agreement:

          (a)  to keep JCC continuously and fully informed as to the
               composition of its investment portfolio and the
               nature of all of its assets and liabilities from time
               to time;

           (b) to furnish JCC with a certified copy of any financial
               statement or report prepared for it by certified or
               independent public accountants and with copies of any
               financial statements or reports made to its
               shareholders or to any governmental body or
               securities exchange;

           (c) to furnish JCC with any further materials or
               information which JCC may reasonably request to
               enable it to perform its function under this
               Agreement; and

           (d) to compensate JCC for its services and reimburse JCC
               for its expenses incurred hereunder in accordance
               with the provisions hereof.

     4.   Compensation. The Trust shall pay to JCC for its investment advisory
services a fee, calculated and payable for each day that this Agreement is in
effect, of 1/365 of 0.75% of the first $300,000,000 of the daily closing net
asset value of the Fund, plus 1/365 of 0.70% of the next $200,000,000 of the
daily closing net asset value of the Fund, plus 1/365 of 0.65% of the daily
closing net asset value of the Fund in excess of $500,000,000. The fee shall be
paid monthly.

     5.   Expenses Borne by JCC. In addition to the expenses which JCC may
incur in the performance of its investment advisory functions under this
Agreement, and the expenses which it may expressly undertake to incur and pay
under other agreements with the Trust or otherwise, JCC shall incur and pay the
following expenses relating to the Fund's operations without reimbursement from
the Fund:


                                      - 2 -
<PAGE>


          (a)  Reasonable compensation, fees and related expenses of
               the Trust's officers and its Trustees (the
               "Trustees"), except for such Trustees who are not
               interested persons of JCC;

          (b)  Rental of offices of the Trust; and

          (c)  All expenses of promoting the sale of shares of the Fund, other
               than expenses incurred in complying with federal and state laws
               and the law of any foreign country or territory or other
               jurisdiction applicable to the issue, offer or sale of shares of
               the Fund including without limitation registration fees and
               costs, the costs of preparing the Fund's registration statement
               and amendments thereto, and the costs and expenses of preparing,
               printing, and mailing prospectuses (and statements of additional
               information) to persons other than shareholders of the Fund.

     6.   Expenses Borne by the Trust. The Trust assumes and shall pay all
expenses incidental to its organization, operations and business not
specifically assumed or agreed to be paid by JCC pursuant to Sections 2 and 5
hereof, including, but not limited to, investment adviser fees; any
compensation, fees, or reimbursements which the Trust pays to its Trustees who
are not interested persons of JCC; compensation of the Fund's custodian,
transfer agent, registrar and dividend disbursing agent; legal, accounting,
audit and printing expenses; administrative, clerical, recordkeeping and
bookkeeping expenses; brokerage commissions and all other expenses in connection
with execution of portfolio transactions (including any appropriate commissions
paid to JCC or its affiliates for effecting exchange listed, over-the-counter or
other securities transactions); interest; all federal, state and local taxes
(including stamp, excise, income and franchise taxes); costs of stock
certificates and expenses of delivering such certificates to the purchaser
thereof; expenses of local representation in Massachusetts; expenses of
shareholders' meetings and of preparing, printing and distributing proxy
statements, notices, and reports to shareholders; expenses of preparing and
filing reports and tax returns with federal and state regulatory authorities;
all expenses incurred in complying with all federal and state laws and the laws
of any foreign country applicable to the issue, offer, or sale of shares of the
Fund, including, but not limited to, all costs involved in the registration or
qualification of shares of the Fund for sale in any jurisdiction, the costs of
portfolio pricing services and systems for compliance with blue sky laws, and
all costs involved in preparing, printing and mailing prospectuses and
statements of additional information of the Fund; and all fees, dues and other
expenses incurred by the Trust in connection with the membership of the Trust in
any trade association or other investment company organization. To the extent
that JCC shall perform any of the above described administrative and clerical
functions, including transfer agency, registry, dividend disbursing,
recordkeeping, bookkeeping, accounting and blue sky monitoring and registration
functions, and the preparation of reports and returns, the Trust shall pay to
JCC compensation for, or reimburse JCC for its expenses incurred in connection
with, such services as JCC and the Trust shall agree from time to time, any
other provision of this Agreement notwithstanding.


                                     - 3 -

<PAGE>


     7.   Treatment of Investment Advice. The Trust shall treat the investment
advice and recommendations of JCC as being advisory only, and shall retain full
control over its own investment policies. However, the Trustees may delegate to
the appropriate officers of the Trust, or to a committee of the Trustees, the
power to authorize purchases, sales or other actions affecting the portfolio of
the Fund in the interim between meetings of the Trustees.

     8.   Brokerage Commissions. For purposes of this Agreement, brokerage
commissions paid by the Fund upon the purchase or sale of its portfolio
securities shall be considered a cost of securities of the Fund and shall be
paid by the Fund. JCC is authorized and directed to place Fund portfolio
transactions only with brokers and dealers who render satisfactory service in
the execution of orders at the most favorable prices and at reasonable
commission rates, provided, however, that JCC may pay a broker or dealer an
amount of commission for effecting a securities transaction in excess of the
amount of commission another broker or dealer would have charged for effecting
that transaction if JCC determines in good faith that such amount of commission
was reasonable in relation to the value of the brokerage and research services
provided by such broker or dealer viewed in terms of either that particular
transaction or the overall responsibilities of JCC. JCC is also authorized to
consider sales of Trust shares as a factor in selecting broker-dealers to
execute Fund portfolio transactions. In placing portfolio business with such
broker-dealers, JCC shall seek the best execution of each transaction. Subject
to the terms of this Agreement and the applicable requirements and provisions of
the law, including the Investment Company Act of 1940 and the Securities
Exchange Act of 1934, as amended, and in the event that JCC or an affiliate is
registered as a broker-dealer, JCC may select a broker or dealer with which it
or the Fund is affiliated. JCC or such affiliated broker-dealer may effect or
execute Fund portfolio transactions, whether on a securities exchange or in the
over-the-counter market, and receive separate compensation from the Fund
therefor. Notwithstanding the foregoing, the Trust shall retain the right to
direct the placement of all portfolio transactions, and the Trustees of the
Trust may establish policies or guidelines to be followed by JCC in placing
portfolio transactions for the Trust pursuant to the foregoing provisions. JCC
shall report on the placement of portfolio transactions in the prior fiscal
quarter at each quarterly meeting of such Trustees.

     9.   Termination. This Agreement may be terminated at any time, without
penalty, by the Board of Trustees of the Trust, or by the shareholders of the
Trust acting by vote of at least a majority of its outstanding voting
securities, provided in either case that sixty (60) days advance written notice
of termination be given to JCC at its principal place of business. This
Agreement may be terminated by JCC at any time, without penalty, by giving sixty
(60) days advance written notice of termination to the Trust, addressed to its
principal place of business. The Trust agrees that, consistent with the terms of
the Trust's Declaration of Trust, the Trust shall cease to use the name "Janus"
in connection with the Fund as soon as reasonably practicable following any
termination of this Agreement if JCC does not continue to provide investment
advice to the Fund after such termination.

     10.  Assignment. This Agreement shall terminate automatically in the
event of any assignment of this Agreement.


                                     - 4 -

<PAGE>


     11.  Term. This Agreement shall continue in effect until July 1, 1998,
unless sooner terminated in accordance with its terms, and shall continue in
effect from year to year thereafter only so long as such continuance is
specifically approved at least annually by the vote of a majority of the
Trustees of the Trust who are not parties hereto or interested persons of any
such party, cast in person at a meeting called for the purpose of voting on the
approval of the terms of such renewal, and by either the Board of Trustees of
the Trust or the affirmative vote of a majority of the outstanding voting
securities of the Trust. The annual approvals provided for herein shall be
effective to continue this Agreement from year to year if given within a period
beginning not more than sixty (60) days prior to July 1 of each applicable year,
notwithstanding the fact that more than three hundred sixty-five (365) days may
have elapsed since the date on which such approval was last given.

     12.  Amendments. This Agreement may be amended by the parties only if
such amendment is specifically approved (i) by a majority of the Trustees,
including a majority of the Trustees who are not interested persons (as that
phrase is defined in Section 2(a)(19) of the 1940 Act) of JCC and, if required
by applicable law, (ii) by the affirmative vote of a majority of the outstanding
voting securities of the Trust (as that phrase is defined in Section 2(a)(42) of
the 1940 Act).

     13.  Other Series. The Trustees shall determine the basis for making an
appropriate allocation of the Trust's expenses (other than those directly
attributable to the Fund) between the Fund and the other series of the Trust.

     14.  Limitation of Personal Liability. All the parties hereto
acknowledge and agree that all liabilities of the Trust arising, directly or
indirectly, under this Agreement, of any and every nature whatsoever, shall be
satisfied solely out of the assets of the Fund and that no Trustee, officer or
holder of shares of beneficial interest of the Trust shall be personally liable
for any of the foregoing liabilities. The Trust's Declaration of Trust, as
amended from time to time, is on file in the Office of the Secretary of State of
the Commonwealth of Massachusetts. Such Declaration of Trust describes in detail
the respective responsibilities and limitations on liability of the Trustees,
officers and holders of shares of beneficial interest of the Trust.

     15.  Limitation of Liability of JCC. JCC shall not be liable for any
error of judgment or mistake of law or for any loss arising out of any
investment or for any act or omission taken with respect to the Trust, except
for willful misfeasance, bad faith or gross negligence in the performance of its
duties, or by reason of reckless disregard of its obligations and duties
hereunder and except to the extent otherwise provided by law. As used in this
Section 15, "JCC" shall include any affiliate of JCC performing services for the
Trust contemplated hereunder and directors, officers and employees of JCC and
such affiliates.


                                     - 5 -

<PAGE>


     16.  Activities of JCC. The services of JCC to the Trust hereunder are
not to be deemed to be exclusive, and JCC and its affiliates are free to render
services to other parties. It is understood that trustees, officers and
shareholders of the Trust are or may become interested in JCC as directors,
officers and shareholders of JCC, that directors, officers, employees and
shareholders of JCC are or may become similarly interested in the Trust, and
that JCC may become interested in the Trust as a shareholder or otherwise.

     17.  Certain Definitions. The terms "vote of a majority of the
outstanding voting securities", "assignment" and "interested persons" when used
herein, shall have the respective meanings specified in the 1940 Act, as now in
effect or hereafter amended, and the rules and regulations thereunder, subject
o such orders, exemptions and interpretations as may be issued by the
Securities and Exchange Commission under said Act and as may be then in effect.

     IN WITNESS WHEREOF, the parties have caused their duly authorized
officers to execute this Investment Advisory Agreement as of this 1st day of
July, 1997.


                                        JANUS CAPITAL CORPORATION



                                        By: /s/ Steven R. Goodbarn
                                            Steven R. Goodbarn, Vice President


                                        JANUS INVESTMENT FUND



                                        By: /s/ Thomas H. Bailey
                                            Thomas H. Bailey, President


                                     - 6 -

<PAGE>


                             JANUS INVESTMENT FUND

                         INVESTMENT ADVISORY AGREEMENT

                              JANUS WORLDWIDE FUND


     THIS INVESTMENT ADVISORY AGREEMENT (the "Agreement") is made this 1st
day of July, 1997, between JANUS INVESTMENT FUND, a Massachusetts business trust
(the "Trust"), and JANUS CAPITAL CORPORATION, a Colorado corporation ("JCC").

                              W I T N E S S E T H:

     WHEREAS, the Trust is registered as an open-end management investment
company under the Investment Company Act of 1940, as amended (the "1940 Act"),
and has registered its shares for public offering under the Securities Act of
1933, as amended (the "1933 Act"); and

     WHEREAS, the Trust is authorized to create separate funds, each with
its own separate investment portfolio of which the beneficial interests are
represented by a separate series of shares; one of such funds created by the
Trust being designated as the Janus Worldwide Fund (the "Fund"); and

     WHEREAS, the Trust and JCC deem it mutually advantageous that JCC
should assist the Board of Trustees and officers of the Trust in the management
of the securities portfolio of the Fund.

     NOW, THEREFORE, the parties agree as follows:

     1.   Investment Advisory Services. JCC shall furnish continuous advice
and recommendations to the Fund as to the acquisition, holding, or disposition
of any or all of the securities or other assets which the Fund may own or
contemplate acquiring from time to time. JCC shall give due consideration to the
investment policies and restrictions and the other statements concerning the
Fund in the Trust's declaration of trust, bylaws, and registration statements
under the 1940 Act and the 1933 Act, and to the provisions of the Internal
Revenue Code, as amended from time to time, applicable to the Fund as a
regulated investment company. In addition, JCC shall cause its officers to
attend meetings and furnish oral or written reports, as the Trust may reasonably
require, in order to keep the Board of Trustees and appropriate officers of the
Trust fully informed as to the condition of the investment portfolio of the
Fund, the investment recommendations of JCC, and the investment considerations
which have given rise to those recommendations. JCC shall supervise the purchase
and sale of securities as directed by the appropriate officers of the Trust.

     2.   Other Services. JCC is hereby authorized (to the extent the Trust
has not otherwise contracted) but not obligated (to the extent it so notifies
the Board of Trustees at least 60 days in advance), to perform (or arrange for
the performance by affiliates of) the management and


                                     - 1 -

<PAGE>


administrative services necessary for the operation of the Fund. JCC is
specifically authorized, on behalf of the Trust, to conduct relations with
custodians, depositories, transfer and pricing agents, accountants, attorneys,
underwriters, brokers and dealers, corporate fiduciaries, insurers, banks and
such other persons in any such other capacity deemed by JCC to be necessary or
desirable. JCC shall generally monitor and report to Fund officers the Fund's
compliance with investment policies and restrictions as set forth in the
currently effective prospectus and statement of additional information relating
to the shares of the Fund under the Securities Act of 1933, as amended. JCC
shall make reports to the Trust's Board of Trustees of its performance of
services hereunder upon request therefor and furnish advice and recommendations
with respect to such other aspects of the business and affairs of the Fund as it
shall determine to be desirable. JCC is also authorized, subject to review by
the Board of Trustees, to furnish such other services as the Adviser shall from
time to time determine to be necessary or useful to perform the services
contemplated by this Agreement.

     3.   Obligations of Trust. The Trust shall have the following obligations
under this Agreement:

          (a)  to keep JCC continuously and fully informed as to the
               composition of its investment portfolio and the
               nature of all of its assets and liabilities from time
               to time;

          (b)  to furnish JCC with a certified copy of any financial
               statement or report prepared for it by certified or
               independent public accountants and with copies of any
               financial statements or reports made to its
               shareholders or to any governmental body or
               securities exchange;

          (c)  to furnish JCC with any further materials or information which
               JCC may reasonably request to enable it to perform its function
               under this Agreement; and

          (d)  to compensate JCC for its services and reimburse JCC
               for its expenses incurred hereunder in accordance
               with the provisions hereof.

     4.   Compensation. The Trust shall pay to JCC for its investment advisory
services a fee, calculated and payable for each day that this Agreement is in
effect, of 1/365 of 0.75% of the first $300,000,000 of the daily closing net
asset value of the Fund, plus 1/365 of 0.70% of the next $200,000,000 of the
daily closing net asset value of the Fund, plus 1/365 of 0.65% of the daily
closing net asset value of the Fund in excess of $500,000,000. The fee shall be
paid monthly.

     5.   Expenses Borne by JCC. In addition to the expenses which JCC may
incur in the performance of its investment advisory functions under this
Agreement, and the expenses which it may expressly undertake to incur and pay
under other agreements with the Trust or otherwise, JCC shall incur and pay the
following expenses relating to the Fund's operations without reimbursement from
the Fund:


                                     - 2 -

<PAGE>


          (a)  Reasonable compensation, fees and related expenses of
               the Trust's officers and its Trustees (the
               "Trustees"), except for such Trustees who are not
               interested persons of JCC;

          (b)  Rental of offices of the Trust; and

          (c)  All expenses of promoting the sale of shares of the Fund, other
               than expenses incurred in complying with federal and state laws
               and the law of any foreign country or territory or other
               jurisdiction applicable to the issue, offer or sale of shares of
               the Fund including without limitation registration fees and
               costs, the costs of preparing the Fund's registration statement
               and amendments thereto, and the costs and expenses of preparing,
               printing, and mailing prospectuses (and statements of additional
               information) to persons other than shareholders of the Fund.

     6.   Expenses Borne by the Trust. The Trust assumes and shall pay all
expenses incidental to its organization, operations and business not
specifically assumed or agreed to be paid by JCC pursuant to Sections 2 and 5
hereof, including, but not limited to, investment adviser fees; any
compensation, fees, or reimbursements which the Trust pays to its Trustees who
are not interested persons of JCC; compensation of the Fund's custodian,
transfer agent, registrar and dividend disbursing agent; legal, accounting,
audit and printing expenses; administrative, clerical, recordkeeping and
bookkeeping expenses; brokerage commissions and all other expenses in connection
with execution of portfolio transactions (including any appropriate commissions
paid to JCC or its affiliates for effecting exchange listed, over-the-counter or
other securities transactions); interest; all federal, state and local taxes
(including stamp, excise, income and franchise taxes); costs of stock
certificates and expenses of delivering such certificates to the purchaser
thereof; expenses of local representation in Massachusetts; expenses of
shareholders' meetings and of preparing, printing and distributing proxy
statements, notices, and reports to shareholders; expenses of preparing and
filing reports and tax returns with federal and state regulatory authorities;
all expenses incurred in complying with all federal and state laws and the laws
of any foreign country applicable to the issue, offer, or sale of shares of the
Fund, including, but not limited to, all costs involved in the registration or
qualification of shares of the Fund for sale in any jurisdiction, the costs of
portfolio pricing services and systems for compliance with blue sky laws, and
all costs involved in preparing, printing and mailing prospectuses and
statements of additional information of the Fund; and all fees, dues and other
expenses incurred by the Trust in connection with the membership of the Trust in
any trade association or other investment company organization. To the extent
that JCC shall perform any of the above described administrative and clerical
functions, including transfer agency, registry, dividend disbursing,
recordkeeping, bookkeeping, accounting and blue sky monitoring and registration
functions, and the preparation of reports and returns, the Trust shall pay to
JCC compensation for, or reimburse JCC for its expenses incurred in connection
with, such services as JCC and the Trust shall agree from time to time, any
other provision of this Agreement notwithstanding.


                                     - 3 -

<PAGE>


     7.   Treatment of Investment Advice. The Trust shall treat the investment
advice and recommendations of JCC as being advisory only, and shall retain full
control over its own investment policies. However, the Trustees may delegate to
the appropriate officers of the Trust, or to a committee of the Trustees, the
power to authorize purchases, sales or other actions affecting the portfolio of
the Fund in the interim between meetings of the Trustees.

     8.   Brokerage Commissions. For purposes of this Agreement, brokerage
commissions paid by the Fund upon the purchase or sale of its portfolio
securities shall be considered a cost of securities of the Fund and shall be
paid by the Fund. JCC is authorized and directed to place Fund portfolio
transactions only with brokers and dealers who render satisfactory service in
the execution of orders at the most favorable prices and at reasonable
commission rates, provided, however, that JCC may pay a broker or dealer an
amount of commission for effecting a securities transaction in excess of the
amount of commission another broker or dealer would have charged for effecting
that transaction if JCC determines in good faith that such amount of commission
was reasonable in relation to the value of the brokerage and research services
provided by such broker or dealer viewed in terms of either that particular
transaction or the overall responsibilities of JCC. JCC is also authorized to
consider sales of Trust shares as a factor in selecting broker-dealers to
execute Fund portfolio transactions. In placing portfolio business with such
broker-dealers, JCC shall seek the best execution of each transaction. Subject
to the terms of this Agreement and the applicable requirements and provisions of
the law, including the Investment Company Act of 1940 and the Securities
Exchange Act of 1934, as amended, and in the event that JCC or an affiliate is
registered as a broker-dealer, JCC may select a broker or dealer with which it
or the Fund is affiliated. JCC or such affiliated broker-dealer may effect or
execute Fund portfolio transactions, whether on a securities exchange or in the
over-the-counter market, and receive separate compensation from the Fund
therefor. Notwithstanding the foregoing, the Trust shall retain the right to
direct the placement of all portfolio transactions, and the Trustees of the
Trust may establish policies or guidelines to be followed by JCC in placing
portfolio transactions for the Trust pursuant to the foregoing provisions. JCC
shall report on the placement of portfolio transactions in the prior fiscal
quarter at each quarterly meeting of such Trustees.

     9.   Termination. This Agreement may be terminated at any time, without
penalty, by the Board of Trustees of the Trust, or by the shareholders of the
Trust acting by vote of at least a majority of its outstanding voting
securities, provided in either case that sixty (60) days advance written notice
of termination be given to JCC at its principal place of business. This
Agreement may be terminated by JCC at any time, without penalty, by giving sixty
(60) days advance written notice of termination to the Trust, addressed to its
principal place of business. The Trust agrees that, consistent with the terms of
the Trust's Declaration of Trust, the Trust shall cease to use the name "Janus"
in connection with the Fund as soon as reasonably practicable following any
termination of this Agreement if JCC does not continue to provide investment
advice to the Fund after such termination.

     10.  Assignment. This Agreement shall terminate automatically in the
event of any assignment of this Agreement.


                                     - 4 -

<PAGE>


     11.  Term. This Agreement shall continue in effect until July 1, 1998,
unless sooner terminated in accordance with its terms, and shall continue in
effect from year to year thereafter only so long as such continuance is
specifically approved at least annually by the vote of a majority of the
Trustees of the Trust who are not parties hereto or interested persons of any
such party, cast in person at a meeting called for the purpose of voting on the
approval of the terms of such renewal, and by either the Board of Trustees of
the Trust or the affirmative vote of a majority of the outstanding voting
securities of the Trust. The annual approvals provided for herein shall be
effective to continue this Agreement from year to year if given within a period
beginning not more than sixty (60) days prior to July 1 of each applicable year,
notwithstanding the fact that more than three hundred sixty-five (365) days may
have elapsed since the date on which such approval was last given.

     12.  Amendments. This Agreement may be amended by the parties only if
such amendment is specifically approved (i) by a majority of the Trustees,
including a majority of the Trustees who are not interested persons (as that
phrase is defined in Section 2(a)(19) of the 1940 Act) of JCC and, if required
by applicable law, (ii) by the affirmative vote of a majority of the outstanding
voting securities of the Trust (as that phrase is defined in Section 2(a)(42) of
the 1940 Act).

     13.  Other Series. The Trustees shall determine the basis for making an
appropriate allocation of the Trust's expenses (other than those directly
attributable to the Fund) between the Fund and the other series of the Trust.

     14.  Limitation of Personal Liability. All the parties hereto
acknowledge and agree that all liabilities of the Trust arising, directly or
indirectly, under this Agreement, of any and every nature whatsoever, shall be
satisfied solely out of the assets of the Fund and that no Trustee, officer or
holder of shares of beneficial interest of the Trust shall be personally liable
for any of the foregoing liabilities. The Trust's Declaration of Trust, as
amended from time to time, is on file in the Office of the Secretary of State of
the Commonwealth of Massachusetts. Such Declaration of Trust describes in detail
the respective responsibilities and limitations on liability of the Trustees,
officers and holders of shares of beneficial interest of the Trust.

     15.  Limitation of Liability of JCC. JCC shall not be liable for any
error of judgment or mistake of law or for any loss arising out of any
investment or for any act or omission taken with respect to the Trust, except
for willful misfeasance, bad faith or gross negligence in the performance of its
duties, or by reason of reckless disregard of its obligations and duties
hereunder and except to the extent otherwise provided by law. As used in this
Section 15, "JCC" shall include any affiliate of JCC performing services for the
Trust contemplated hereunder and directors, officers and employees of JCC and
such affiliates.

     16.  Activities of JCC. The services of JCC to the Trust hereunder are
not to be deemed to be exclusive, and JCC and its affiliates are free to render
services to other parties. It is understood that trustees, officers and
shareholders of the Trust are or may become interested in JCC as directors,


                                     - 5 -

<PAGE>


officers and shareholders of JCC, that directors, officers, employees and
shareholders of JCC are or may become similarly interested in the Trust, and
that JCC may become interested in the Trust as a shareholder or otherwise.

     17.  Certain Definitions. The terms "vote of a majority of the
outstanding voting securities", "assignment" and "interested persons" when used
herein, shall have the respective meanings specified in the 1940 Act, as now in
effect or hereafter amended, and the rules and regulations thereunder, subject
to such orders, exemptions and interpretations as may be issued by the
Securities and Exchange Commission under said Act and as may be then in effect.

     IN WITNESS WHEREOF, the parties have caused their duly authorized
officers to execute this Investment Advisory Agreement as of this 1st day of
July, 1997.


                                   JANUS CAPITAL CORPORATION



                                   By: /s/ Steven R. Goodbarn
                                       Steven R. Goodbarn, Vice President


                                   JANUS INVESTMENT FUND



                                   By: /s/ Thomas H. Bailey
                                       Thomas H. Bailey, President


                                     - 6 -






                                                            EXHIBIT 5(c)

                             JANUS INVESTMENT FUND

                         INVESTMENT ADVISORY AGREEMENT

                               JANUS TWENTY FUND


     THIS INVESTMENT ADVISORY AGREEMENT (the "Agreement") is made this 1st
day of July, 1997, between JANUS INVESTMENT FUND, a Massachusetts business trust
(the "Trust"), and JANUS CAPITAL CORPORATION, a Colorado corporation ("JCC").

                              W I T N E S S E T H:

     WHEREAS, the Trust is registered as an open-end management investment
company under the Investment Company Act of 1940, as amended (the "1940 Act"),
and has registered its shares for public offering under the Securities Act of
1933, as amended (the "1933 Act"); and

     WHEREAS, the Trust is authorized to create separate funds, each with
its own separate investment portfolio of which the beneficial interests are
represented by a separate series of shares; one of such funds created by the
Trust being designated as the Janus Twenty Fund (the "Fund"); and

     WHEREAS, the Trust and JCC deem it mutually advantageous that JCC
should assist the Board of Trustees and officers of the Trust in the management
of the securities portfolio of the Fund.

     NOW, THEREFORE, the parties agree as follows:

     1.   Investment Advisory Services. JCC shall furnish continuous advice
and recommendations to the Fund as to the acquisition, holding, or disposition
of any or all of the securities or other assets which the Fund may own or
contemplate acquiring from time to time. JCC shall give due consideration to the
investment policies and restrictions and the other statements concerning the
Fund in the Trust's declaration of trust, bylaws, and registration statements
under the 1940 Act and the 1933 Act, and to the provisions of the Internal
Revenue Code, as amended from time to time, applicable to the Fund as a
regulated investment company. In addition, JCC shall cause its officers to
attend meetings and furnish oral or written reports, as the Trust may reasonably
require, in order to keep the Board of Trustees and appropriate officers of the
Trust fully informed as to the condition of the investment portfolio of the
Fund, the investment recommendations of JCC, and the investment considerations
which have given rise to those recommendations. JCC shall supervise the purchase
and sale of securities as directed by the appropriate officers of the Trust.

     2.   Other Services. JCC is hereby authorized (to the extent the Trust
has not otherwise contracted) but not obligated (to the extent it so notifies
the Board of Trustees at least 60 days in advance), to perform (or arrange for
the performance by affiliates of) the management and administrative services
necessary for the operation of the Fund. JCC is specifically authorized, on


                                     - 1 -

<PAGE>


behalf of the Trust, to conduct relations with custodians, depositories,
transfer and pricing agents, accountants, attorneys, underwriters, brokers and
dealers, corporate fiduciaries, insurers, banks and such other persons in any
such other capacity deemed by JCC to be necessary or desirable. JCC shall
generally monitor and report to Fund officers the Fund's compliance with
investment policies and restrictions as set forth in the currently effective
prospectus and statement of additional information relating to the shares of the
Fund under the Securities Act of 1933, as amended. JCC shall make reports to the
Trust's Board of Trustees of its performance of services hereunder upon request
therefor and furnish advice and recommendations with respect to such other
aspects of the business and affairs of the Fund as it shall determine to be
desirable. JCC is also authorized, subject to review by the Board of Trustees,
to furnish such other services as the Adviser shall from time to time determine
to be necessary or useful to perform the services contemplated by this
Agreement.

     3. Obligations of Trust. The Trust shall have the following obligations
under this Agreement:

          (a)  to keep JCC continuously and fully informed as to the
               composition of its investment portfolio and the
               nature of all of its assets and liabilities from time
               to time;

          (b)  to furnish JCC with a certified copy of any financial
               statement or report prepared for it by certified or
               independent public accountants and with copies of any
               financial statements or reports made to its
               shareholders or to any governmental body or
               securities exchange;

          (c)  to furnish JCC with any further materials or
               information which JCC may reasonably request to
               enable it to perform its function under this
               Agreement; and

          (d)  to compensate JCC for its services and reimburse JCC
               for its expenses incurred hereunder in accordance
               with the provisions hereof.

     4.   Compensation. The Trust shall pay to JCC for its investment advisory
services a fee, calculated and payable for each day that this Agreement is in
effect, of 1/365 of 0.75% of the first $300,000,000 of the daily closing net
asset value of the Fund, plus 1/365 of 0.70% of the next $200,000,000 of the
daily closing net asset value of the Fund, plus 1/365 of 0.65% of the daily
closing net asset value of the Fund in excess of $500,000,000. The fee shall be
paid monthly.

     5.   Expenses Borne by JCC. In addition to the expenses which JCC may
incur in the performance of its investment advisory functions under this
Agreement, and the expenses which it may expressly undertake to incur and pay
under other agreements with the Trust or otherwise, JCC shall incur and pay the
following expenses relating to the Fund's operations without reimbursement from
the Fund:


                                     - 2 -

<PAGE>


          (a)  Reasonable compensation, fees and related expenses of
               the Trust's officers and its Trustees (the
               "Trustees"), except for such Trustees who are not
               interested persons of JCC;

          (b)  Rental of offices of the Trust; and

          (c)  All expenses of promoting the sale of shares of the Fund, other
               than expenses incurred in complying with federal and state laws
               and the law of any foreign country or territory or other 
               jurisdiction applicable to the issue, offer or sale
               of shares of the Fund including without limitation registration
               fees and costs, the costs of preparing the Fund's registration
               statement and amendments thereto, and the costs and expenses of
               preparing, printing, and mailing prospectuses (and statements
               of additional information) to persons other than shareholders 
               of the Fund.

     6.   Expenses Borne by the Trust. The Trust assumes and shall pay all
expenses incidental to its organization, operations and business not
specifically assumed or agreed to be paid by JCC pursuant to Sections 2 and 5
hereof, including, but not limited to, investment adviser fees; any
compensation, fees, or reimbursements which the Trust pays to its Trustees who
are not interested persons of JCC; compensation of the Fund's custodian,
transfer agent, registrar and dividend disbursing agent; legal, accounting,
audit and printing expenses; administrative, clerical, recordkeeping and
bookkeeping expenses; brokerage commissions and all other expenses in connection
with execution of portfolio transactions (including any appropriate commissions
paid to JCC or its affiliates for effecting exchange listed, over-the-counter or
other securities transactions); interest; all federal, state and local taxes
(including stamp, excise, income and franchise taxes); costs of stock
certificates and expenses of delivering such certificates to the purchaser
thereof; expenses of local representation in Massachusetts; expenses of
shareholders' meetings and of preparing, printing and distributing proxy
statements, notices, and reports to shareholders; expenses of preparing and
filing reports and tax returns with federal and state regulatory authorities;
all expenses incurred in complying with all federal and state laws and the laws
of any foreign country applicable to the issue, offer, or sale of shares of the
Fund, including, but not limited to, all costs involved in the registration or
qualification of shares of the Fund for sale in any jurisdiction, the costs of
portfolio pricing services and systems for compliance with blue sky laws, and
all costs involved in preparing, printing and mailing prospectuses and
statements of additional information of the Fund; and all fees, dues and other
expenses incurred by the Trust in connection with the membership of the Trust in
any trade association or other investment company organization. To the extent
that JCC shall perform any of the above described administrative and clerical
functions, including transfer agency, registry, dividend disbursing,
recordkeeping, bookkeeping, accounting and blue sky monitoring and registration
functions, and the preparation of reports and returns, the Trust shall pay to
JCC compensation for, or reimburse JCC for its expenses incurred in connection
with, such services as JCC and the Trust shall agree from time to time, any
other provision of this Agreement notwithstanding.


                                     - 3 -

<PAGE>


     7.   Treatment of Investment Advice. The Trust shall treat the 
investment advice and recommendations of JCC as being advisory only, and shall
retain full control over its own investment policies. However, the Trustees may
delegate to the appropriate officers of the Trust, or to a committee of the 
Trustees, the power to authorize purchases, sales or other actions affecting
the portfolio of the Fund in the interim between meetings of the Trustees.

     8.   Brokerage Commissions. For purposes of this Agreement, brokerage
commissions paid by the Fund upon the purchase or sale of its portfolio
securities shall be considered a cost of securities of the Fund and shall be
paid by the Fund. JCC is authorized and directed to place Fund portfolio
transactions only with brokers and dealers who render satisfactory service in
the execution of orders at the most favorable prices and at reasonable
commission rates, provided, however, that JCC may pay a broker or dealer an
amount of commission for effecting a securities transaction in excess of the
amount of commission another broker or dealer would have charged for effecting
that transaction if JCC determines in good faith that such amount of commission
was reasonable in relation to the value of the brokerage and research services
provided by such broker or dealer viewed in terms of either that particular
transaction or the overall responsibilities of JCC. JCC is also authorized to
consider sales of Trust shares as a factor in selecting broker-dealers to
execute Fund portfolio transactions. In placing portfolio business with such
broker-dealers, JCC shall seek the best execution of each transaction. Subject
to the terms of this Agreement and the applicable requirements and provisions of
the law, including the Investment Company Act of 1940 and the Securities
Exchange Act of 1934, as amended, and in the event that JCC or an affiliate is
registered as a broker-dealer, JCC may select a broker or dealer with which it
or the Fund is affiliated. JCC or such affiliated broker-dealer may effect or
execute Fund portfolio transactions, whether on a securities exchange or in the
over-the-counter market, and receive separate compensation from the Fund
therefor. Notwithstanding the foregoing, the Trust shall retain the right to
direct the placement of all portfolio transactions, and the Trustees of the
Trust may establish policies or guidelines to be followed by JCC in placing
portfolio transactions for the Trust pursuant to the foregoing provisions. JCC
shall report on the placement of portfolio transactions in the prior fiscal
quarter at each quarterly meeting of such Trustees.

     9.   Termination. This Agreement may be terminated at any time, without
penalty, by the Board of Trustees of the Trust, or by the shareholders of the
Trust acting by vote of at least a majority of its outstanding voting
securities, provided in either case that sixty (60) days advance written notice
of termination be given to JCC at its principal place of business. This
Agreement may be terminated by JCC at any time, without penalty, by giving sixty
(60) days advance written notice of termination to the Trust, addressed to its
principal place of business. The Trust agrees that, consistent with the terms of
the Trust's Declaration of Trust, the Trust shall cease to use the name "Janus"
in connection with the Fund as soon as reasonably practicable following any
termination of this Agreement if JCC does not continue to provide investment
advice to the Fund after such termination.

     10.  Assignment. This Agreement shall terminate automatically in the
event of any assignment of this Agreement.


                                     - 4 -

<PAGE>


     11.  Term. This Agreement shall continue in effect until July 1, 1998,
unless sooner terminated in accordance with its terms, and shall continue in
effect from year to year thereafter only so long as such continuance is
specifically approved at least annually by the vote of a majority of the
Trustees of the Trust who are not parties hereto or interested persons of any
such party, cast in person at a meeting called for the purpose of voting on the
approval of the terms of such renewal, and by either the Board of Trustees of
the Trust or the affirmative vote of a majority of the outstanding voting
securities of the Trust. The annual approvals provided for herein shall be
effective to continue this Agreement from year to year if given within a period
beginning not more than sixty (60) days prior to July 1 of each applicable year,
notwithstanding the fact that more than three hundred sixty-five (365) days may
have elapsed since the date on which such approval was last given.

     12.  Amendments. This Agreement may be amended by the parties only if
such amendment is specifically approved (i) by a majority of the Trustees,
including a majority of the Trustees who are not interested persons (as that
phrase is defined in Section 2(a)(19) of the 1940 Act) of JCC and, if required
by applicable law, (ii) by the affirmative vote of a majority of the outstanding
voting securities of the Fund (as that phrase is defined in Section 2(a)(42) of
the 1940 Act).

     13.  Other Series. The Trustees shall determine the basis for making an
appropriate allocation of the Trust's expenses (other than those directly
attributable to the Fund) between the Fund and the other series of the Trust.

     14.  Limitation of Personal Liability. All the parties hereto
acknowledge and agree that all liabilities of the Trust arising, directly or
indirectly, under this Agreement, of any and every nature whatsoever, shall be
satisfied solely out of the assets of the Fund and that no Trustee, officer or
holder of shares of beneficial interest of the Trust shall be personally liable
for any of the foregoing liabilities. The Trust's Declaration of Trust, as
amended from time to time, is on file in the Office of the Secretary of State of
the Commonwealth of Massachusetts. Such Declaration of Trust describes in detail
the respective responsibilities and limitations on liability of the Trustees,
officers and holders of shares of beneficial interest of the Trust.

     15.  Limitation of Liability of JCC. JCC shall not be liable for any
error of judgment or mistake of law or for any loss arising out of any
investment or for any act or omission taken with respect to the Trust, except
for willful misfeasance, bad faith or gross negligence in the performance of its
duties, or by reason of reckless disregard of its obligations and duties
hereunder and except to the extent otherwise provided by law. As used in this
Section 15, "JCC" shall include any affiliate of JCC performing services for the
Trust contemplated hereunder and directors, officers and employees of JCC and
such affiliates.

     16.  Activities of JCC. The services of JCC to the Trust hereunder are
not to be deemed to be exclusive, and JCC and its affiliates are free to render
services to other parties. It is understood that trustees, officers and
shareholders of the Trust are or may become interested in JCC as directors,


                                     - 5 -

<PAGE>


officers and shareholders of JCC, that directors, officers, employees and
shareholders of JCC are or may become similarly interested in the Trust, and
that JCC may become interested in the Trust as a shareholder or otherwise.

     17.  Certain Definitions. The terms "vote of a majority of the
outstanding voting securities", "assignment" and "interested persons" when used
herein, shall have the respective meanings specified in the 1940 Act, as now in
effect or hereafter amended, and the rules and regulations thereunder, subject
to such orders, exemptions and interpretations as may be issued by the
Securities and Exchange Commission under said Act and as may be then in effect.

     IN WITNESS WHEREOF, the parties have caused their duly authorized
officers to execute this Investment Advisory Agreement as of this 1st day of
July, 1997.


                                        JANUS CAPITAL CORPORATION



                                        By:  /s/ Steven R. Goodbarn
                                             Steven R. Goodbarn, Vice President


                                        JANUS INVESTMENT FUND



                                         By: /s/ Thomas H. Bailey
                                             Thomas H. Bailey, President


                                     - 6 -

<PAGE>



                             JANUS INVESTMENT FUND

                         INVESTMENT ADVISORY AGREEMENT

                               JANUS VENTURE FUND


     THIS INVESTMENT ADVISORY AGREEMENT (the "Agreement") is made this 1st
day of July, 1997, between JANUS INVESTMENT FUND, a Massachusetts business trust
(the "Trust"), and JANUS CAPITAL CORPORATION, a Colorado corporation ("JCC").

                              W I T N E S S E T H:

     WHEREAS, the Trust is registered as an open-end management investment
company under the Investment Company Act of 1940, as amended (the "1940 Act"),
and has registered its shares for public offering under the Securities Act of
1933, as amended (the "1933 Act"); and

     WHEREAS, the Trust is authorized to create separate funds, each with
its own separate investment portfolio of which the beneficial interests are
represented by a separate series of shares; one of such funds created by the
Trust being designated as the Janus Venture Fund (the "Fund"); and

     WHEREAS, the Trust and JCC deem it mutually advantageous that JCC
should assist the Board of Trustees and officers of the Trust in the management
of the securities portfolio of the Fund.

     NOW, THEREFORE, the parties agree as follows:

     1.   Investment Advisory Services. JCC shall furnish continuous advice
and recommendations to the Fund as to the acquisition, holding, or disposition
of any or all of the securities or other assets which the Fund may own or
contemplate acquiring from time to time. JCC shall give due consideration to the
investment policies and restrictions and the other statements concerning the
Fund in the Trust's declaration of trust, bylaws, and registration statements
under the 1940 Act and the 1933 Act, and to the provisions of the Internal
Revenue Code, as amended from time to time, applicable to the Fund as a
regulated investment company. In addition, JCC shall cause its officers to
attend meetings and furnish oral or written reports, as the Trust may reasonably
require, in order to keep the Board of Trustees and appropriate officers of the
Trust fully informed as to the condition of the investment portfolio of the
Fund, the investment recommendations of JCC, and the investment considerations
which have given rise to those recommendations. JCC shall supervise the purchase
and sale of securities as directed by the appropriate officers of the Trust.

     2. Other Services. JCC is hereby authorized (to the extent the Trust
has not otherwise contracted) but not obligated (to the extent it so notifies
the Board of Trustees at least 60 days in advance), to perform (or arrange for
the performance by affiliates of) the management and administrative services
necessary for the operation of the Fund. JCC is specifically authorized, on


                                     - 1 -

<PAGE>


behalf of the Trust, to conduct relations with custodians, depositories,
transfer and pricing agents, accountants, attorneys, underwriters, brokers and
dealers, corporate fiduciaries, insurers, banks and such other persons in any
such other capacity deemed by JCC to be necessary or desirable. JCC shall
generally monitor and report to Fund officers the Fund's compliance with
investment policies and restrictions as set forth in the currently effective
prospectus and statement of additional information relating to the shares of the
Fund under the Securities Act of 1933, as amended. JCC shall make reports to the
Trust's Board of Trustees of its performance of services hereunder upon request
therefor and furnish advice and recommendations with respect to such other
aspects of the business and affairs of the Fund as it shall determine to be
desirable. JCC is also authorized, subject to review by the Board of Trustees,
to furnish such other services as the Adviser shall from time to time determine
to be necessary or useful to perform the services contemplated by this
Agreement.

     3. Obligations of Trust. The Trust shall have the following obligations
under this Agreement:

          (a)  to keep JCC continuously and fully informed as to the
               composition of its investment portfolio and the
               nature of all of its assets and liabilities from time
               to time;

          (b)  to furnish JCC with a certified copy of any financial
               statement or report prepared for it by certified or
               independent public accountants and with copies of any
               financial statements or reports made to its
               shareholders or to any governmental body or
               securities exchange;

          (c)  to furnish JCC with any further materials or
               information which JCC may reasonably request to
               enable it to perform its function under this
               Agreement; and

          (d)  to compensate JCC for its services and reimburse JCC
               for its expenses incurred hereunder in accordance
               with the provisions hereof.

     4.   Compensation. The Trust shall pay to JCC for its investment advisory
services a fee, calculated and payable for each day that this Agreement is in
effect, of 1/365 of 0.75% of the first $300,000,000 of the daily closing net
asset value of the Fund, plus 1/365 of 0.70% of the next $200,000,000 of the
daily closing net asset value of the Fund, plus 1/365 of 0.65% of the daily
closing net asset value of the Fund in excess of $500,000,000. The fee shall be
paid monthly.

     5.   Expenses Borne by JCC. In addition to the expenses which JCC may
incur in the performance of its investment advisory functions under this
Agreement, and the expenses which it may expressly undertake to incur and pay
under other agreements with the Trust or otherwise, JCC shall incur and pay the
following expenses relating to the Fund's operations without reimbursement from
the Fund:


                                     - 2 -

<PAGE>



          (a)  Reasonable compensation, fees and related expenses of
               the Trust's officers and its Trustees (the
               "Trustees"), except for such Trustees who are not
               interested persons of JCC;

          (b)  Rental of offices of the Trust; and

          (c)  All expenses of promoting the sale of shares of the Fund, other
               than expenses incurred in complying with federal and state laws
               and the law of any foreign country or territory or other 
               jurisdiction applicable to the issue, offer or sale of shares of
               the Fund including without limitation registration fees and 
               costs, the costs of preparing the Fund's registration statement
               and amendments thereto, and the costs and expenses of preparing,
               printing, and mailing prospectuses (and statements of additional
               information) to persons other than shareholders of the Fund.

     6.   Expenses Borne by the Trust. The Trust assumes and shall pay all
expenses incidental to its organization, operations and business not
specifically assumed or agreed to be paid by JCC pursuant to Sections 2 and 5
hereof, including, but not limited to, investment adviser fees; any
compensation, fees, or reimbursements which the Trust pays to its Trustees who
are not interested persons of JCC; compensation of the Fund's custodian,
transfer agent, registrar and dividend disbursing agent; legal, accounting,
audit and printing expenses; administrative, clerical, recordkeeping and
bookkeeping expenses; brokerage commissions and all other expenses in connection
with execution of portfolio transactions (including any appropriate commissions
paid to JCC or its affiliates for effecting exchange listed, over-the-counter or
other securities transactions); interest; all federal, state and local taxes
(including stamp, excise, income and franchise taxes); costs of stock
certificates and expenses of delivering such certificates to the purchaser
thereof; expenses of local representation in Massachusetts; expenses of
shareholders' meetings and of preparing, printing and distributing proxy
statements, notices, and reports to shareholders; expenses of preparing and
filing reports and tax returns with federal and state regulatory authorities;
all expenses incurred in complying with all federal and state laws and the laws
of any foreign country applicable to the issue, offer, or sale of shares of the
Fund, including, but not limited to, all costs involved in the registration or
qualification of shares of the Fund for sale in any jurisdiction, the costs of
portfolio pricing services and systems for compliance with blue sky laws, and
all costs involved in preparing, printing and mailing prospectuses and
statements of additional information of the Fund; and all fees, dues and other
expenses incurred by the Trust in connection with the membership of the Trust in
any trade association or other investment company organization. To the extent
that JCC shall perform any of the above described administrative and clerical
functions, including transfer agency, registry, dividend disbursing,
recordkeeping, bookkeeping, accounting and blue sky monitoring and registration
functions, and the preparation of reports and returns, the Trust shall pay to
JCC compensation for, or reimburse JCC for its expenses incurred in connection
with, such services as JCC and the Trust shall agree from time to time, any
other provision of this Agreement notwithstanding.


                                     - 3 -

<PAGE>


     7.   Treatment of Investment Advice. The Trust shall treat the investment
advice and recommendations of JCC as being advisory only, and shall retain full
control over its own investment policies. However, the Trustees may delegate to
the appropriate officers of the Trust, or to a committee of the Trustees, the
power to authorize purchases, sales or other actions affecting the portfolio of
the Fund in the interim between meetings of the Trustees.

     8.   Brokerage Commissions. For purposes of this Agreement, brokerage
commissions paid by the Fund upon the purchase or sale of its portfolio
securities shall be considered a cost of securities of the Fund and shall be
paid by the Fund. JCC is authorized and directed to place Fund portfolio
transactions only with brokers and dealers who render satisfactory service in
the execution of orders at the most favorable prices and at reasonable
commission rates, provided, however, that JCC may pay a broker or dealer an
amount of commission for effecting a securities transaction in excess of the
amount of commission another broker or dealer would have charged for effecting
that transaction if JCC determines in good faith that such amount of commission
was reasonable in relation to the value of the brokerage and research services
provided by such broker or dealer viewed in terms of either that particular
transaction or the overall responsibilities of JCC. JCC is also authorized to
consider sales of Trust shares as a factor in selecting broker-dealers to
execute Fund portfolio transactions. In placing portfolio business with such
broker-dealers, JCC shall seek the best execution of each transaction. Subject
to the terms of this Agreement and the applicable requirements and provisions of
the law, including the Investment Company Act of 1940 and the Securities
Exchange Act of 1934, as amended, and in the event that JCC or an affiliate is
registered as a broker-dealer, JCC may select a broker or dealer with which it
or the Fund is affiliated. JCC or such affiliated broker-dealer may effect or
execute Fund portfolio transactions, whether on a securities exchange or in the
over-the-counter market, and receive separate compensation from the Fund
therefor. Notwithstanding the foregoing, the Trust shall retain the right to
direct the placement of all portfolio transactions, and the Trustees of the
Trust may establish policies or guidelines to be followed by JCC in placing
portfolio transactions for the Trust pursuant to the foregoing provisions. JCC
shall report on the placement of portfolio transactions in the prior fiscal
quarter at each quarterly meeting of such Trustees.

     9.   Termination. This Agreement may be terminated at any time, without
penalty, by the Board of Trustees of the Trust, or by the shareholders of the
Trust acting by vote of at least a majority of its outstanding voting
securities, provided in either case that sixty (60) days advance written notice
of termination be given to JCC at its principal place of business. This
Agreement may be terminated by JCC at any time, without penalty, by giving sixty
(60) days advance written notice of termination to the Trust, addressed to its
principal place of business. The Trust agrees that, consistent with the terms of
the Trust's Declaration of Trust, the Trust shall cease to use the name "Janus"
in connection with the Fund as soon as reasonably practicable following any
termination of this Agreement if JCC does not continue to provide investment
advice to the Fund after such termination.

     10.  Assignment. This Agreement shall terminate automatically in the
event of any assignment of this Agreement.


                                     - 4 -

<PAGE>


     11.  Term. This Agreement shall continue in effect until July 1, 1998,
unless sooner terminated in accordance with its terms, and shall continue in
effect from year to year thereafter only so long as such continuance is
specifically approved at least annually by the vote of a majority of the
Trustees of the Trust who are not parties hereto or interested persons of any
such party, cast in person at a meeting called for the purpose of voting on the
approval of the terms of such renewal, and by either the Board of Trustees of
the Trust or the affirmative vote of a majority of the outstanding voting
securities of the Trust. The annual approvals provided for herein shall be
effective to continue this Agreement from year to year if given within a period
beginning not more than sixty (60) days prior to July 1 of each applicable year,
notwithstanding the fact that more than three hundred sixty-five (365) days may
have elapsed since the date on which such approval was last given.

     12.  Amendments. This Agreement may be amended by the parties only if
such amendment is specifically approved (i) by a majority of the Trustees,
including a majority of the Trustees who are not interested persons (as that
phrase is defined in Section 2(a)(19) of the 1940 Act) of JCC and, if required
by applicable law, (ii) by the affirmative vote of a majority of the outstanding
voting securities of the Fund (as that phrase is defined in Section 2(a)(42) of
the 1940 Act).

     13.  Other Series. The Trustees shall determine the basis for making an
appropriate allocation of the Trust's expenses (other than those directly
attributable to the Fund) between the Fund and the other series of the Trust.

     14.  Limitation of Personal Liability. All the parties hereto
acknowledge and agree that all liabilities of the Trust arising, directly or
indirectly, under this Agreement, of any and every nature whatsoever, shall be
satisfied solely out of the assets of the Fund and that no Trustee, officer or
holder of shares of beneficial interest of the Trust shall be personally liable
for any of the foregoing liabilities. The Trust's Declaration of Trust, as
amended from time to time, is on file in the Office of the Secretary of State of
the Commonwealth of Massachusetts. Such Declaration of Trust describes in detail
the respective responsibilities and limitations on liability of the Trustees,
officers and holders of shares of beneficial interest of the Trust.

     15.  Limitation of Liability of JCC. JCC shall not be liable for any
error of judgment or mistake of law or for any loss arising out of any
investment or for any act or omission taken with respect to the Trust, except
for willful misfeasance, bad faith or gross negligence in the performance of its
duties, or by reason of reckless disregard of its obligations and duties
hereunder and except to the extent otherwise provided by law. As used in this
Section 15, "JCC" shall include any affiliate of JCC performing services for the
Trust contemplated hereunder and directors, officers and employees of JCC and
such affiliates.

     16.  Activities of JCC. The services of JCC to the Trust hereunder are
not to be deemed to be exclusive, and JCC and its affiliates are free to render
services to other parties. It is understood that trustees, officers and
shareholders of the Trust are or may become interested in JCC as directors,


                                     - 5 -

<PAGE>


officers and shareholders of JCC, that directors, officers, employees and
shareholders of JCC are or may become similarly interested in the Trust, and
that JCC may become interested in the Trust as a shareholder or otherwise.

     17.  Certain Definitions. The terms "vote of a majority of the
outstanding voting securities", "assignment" and "interested persons" when used
herein, shall have the respective meanings specified in the 1940 Act, as now in
effect or hereafter amended, and the rules and regulations thereunder, subject
to such orders, exemptions and interpretations as may be issued by the
Securities and Exchange Commission under said Act and as may be then in effect.

     IN WITNESS WHEREOF, the parties have caused their duly authorized
officers to execute this Investment Advisory Agreement as of this 1st day of
July, 1997.


                                        JANUS CAPITAL CORPORATION



                                        By: /s/ Steven R. Goodbarn
                                            Steven R. Goodbarn, Vice President


                                         JANUS INVESTMENT FUND



                                         By: /s/ Thomas H. Bailey
                                             Thomas H. Bailey, President


                                     - 6 -



                                                                 EXHIBIT 5(d)

                             JANUS INVESTMENT FUND

                          INVESTMENT ADVISORY AGREEMENT

                           JANUS FLEXIBLE INCOME FUND


     THIS INVESTMENT ADVISORY AGREEMENT (the "Agreement") is made this 1st
day of July, 1997, between JANUS INVESTMENT FUND, a Massachusetts business trust
(the "Trust"), and JANUS CAPITAL CORPORATION, a Colorado corporation ("JCC").

                              W I T N E S S E T H:

     WHEREAS, the Trust is registered as an open-end management investment
company under the Investment Company Act of 1940, as amended (the "1940 Act"),
and has registered its shares for public offering under the Securities Act of
1933, as amended (the "1933 Act"); and

     WHEREAS, the Trust is authorized to create separate funds, each with
its own separate investment portfolio of which the beneficial interests are
represented by a separate series of shares; one of such funds created by the
Trust being designated as the Janus Flexible Income Fund (the "Fund"); and

     WHEREAS, the Trust and JCC deem it mutually advantageous that JCC
should assist the Board of Trustees and officers of the Trust in the management
of the securities portfolio of the Fund.

     NOW, THEREFORE, the parties agree as follows:

     1.   Investment Advisory Services. JCC shall furnish continuous advice
and recommendations to the Fund as to the acquisition, holding, or disposition
of any or all of the securities or other assets which the Fund may own or
contemplate acquiring from time to time. JCC shall give due consideration to the
investment policies and restrictions and the other statements concerning the
Fund in the Trust's declaration of trust, bylaws, and registration statements
under the 1940 Act and the 1933 Act, and to the provisions of the Internal
Revenue Code, as amended from time to time, applicable to the Fund as a
regulated investment company. In addition, JCC shall cause its officers to
attend meetings and furnish oral or written reports, as the Trust may reasonably
require, in order to keep the Board of Trustees and appropriate officers of the
Trust fully informed as to the condition of the investment portfolio of the
Fund, the investment recommendations of JCC, and the investment considerations
which have given rise to those recommendations. JCC shall supervise the purchase
and sale of securities as directed by the appropriate officers of the Trust.

     2.   Other Services. JCC is hereby authorized (to the extent the Trust
has not otherwise contracted) but not obligated (to the extent it so notifies
the Board of Trustees at least 60 days in advance), to perform (or arrange for
the performance by affiliates of) the management and


                                     - 1 -

<PAGE>


administrative services necessary for the operation of the Fund. JCC is
specifically authorized, on behalf of the Trust, to conduct relations with
custodians, depositories, transfer and pricing agents, accountants, attorneys,
underwriters, brokers and dealers, corporate fiduciaries, insurers, banks and
such other persons in any such other capacity deemed by JCC to be necessary or
desirable. JCC shall generally monitor and report to Fund officers the Fund's
compliance with investment policies and restrictions as set forth in the
currently effective prospectus and statement of additional information relating
to the shares of the Fund under the Securities Act of 1933, as amended. JCC
shall make reports to the Trust's Board of Trustees of its performance of
services hereunder upon request therefor and furnish advice and recommendations
with respect to such other aspects of the business and affairs of the Fund as it
shall determine to be desirable. JCC is also authorized, subject to review by
the Board of Trustees, to furnish such other services as the Adviser shall from
time to time determine to be necessary or useful to perform the services
contemplated by this Agreement.

     3.   Obligations of Trust. The Trust shall have the following obligations
under this Agreement:

          (a)  to keep JCC continuously and fully informed as to the
               composition of its investment portfolio and the
               nature of all of its assets and liabilities from time
               to time;

          (b)  to furnish JCC with a certified copy of any financial
               statement or report prepared for it by certified or
               independent public accountants and with copies of any
               financial statements or reports made to its
               shareholders or to any governmental body or
               securities exchange;

          (c)  to furnish JCC with any further materials or
               information which JCC may reasonably request to
               enable it to perform its function under this
               Agreement; and

          (d)  to compensate JCC for its services and reimburse JCC
               for its expenses incurred hereunder in accordance
               with the provisions hereof.

     4.   Compensation. The Trust shall pay to JCC for its investment advisory
services a fee, calculated and payable for each day that this Agreement is in
effect, of 1/365 of .65% of the first $300,000,000 of the daily closing net
asset value of the Fund, plus 1/365 of 0.55% of the daily closing net asset
value of the Fund in excess of $300,000,000. The fee shall be paid monthly.

     5.   Expenses Borne by JCC. In addition to the expenses which JCC may
incur in the performance of its investment advisory functions under this
Agreement, and the expenses which it may expressly undertake to incur and pay
under other agreements with the Trust or otherwise, JCC shall incur and pay the
following expenses relating to the Fund's operations without reimbursement from
the Fund:


                                     - 2 -

<PAGE>


          (a)  Reasonable compensation, fees and related expenses of
               the Trust's officers and its Trustees (the
               "Trustees"), except for such Trustees who are not
               interested persons of JCC;

          (b)  Rental of offices of the Trust; and

          (c)  All expenses of promoting the sale of shares of the Fund, other
               than expenses incurred in complying with federal and state laws
               and the law of any foreign country or territory or other 
               jurisdiction applicable to the issue, offer or sale of shares 
               of the Fund including without limitation registration fees and 
               costs, the costs of preparing the Fund's registration statement
               and amendments thereto, and the costs and expenses of preparing,
               printing, and mailing prospectuses (and statements of additional
               information) to persons other than shareholders of the Fund.

     6.   Expenses Borne by the Trust. The Trust assumes and shall pay all
expenses incidental to its organization, operations and business not
specifically assumed or agreed to be paid by JCC pursuant to Sections 2 and 5
hereof, including, but not limited to, investment adviser fees; any
compensation, fees, or reimbursements which the Trust pays to its Trustees who
are not interested persons of JCC; compensation of the Fund's custodian,
transfer agent, registrar and dividend disbursing agent; legal, accounting,
audit and printing expenses; administrative, clerical, recordkeeping and
bookkeeping expenses; brokerage commissions and all other expenses in connection
with execution of portfolio transactions (including any appropriate commissions
paid to JCC or its affiliates for effecting exchange listed, over-the-counter or
other securities transactions); interest; all federal, state and local taxes
(including stamp, excise, income and franchise taxes); costs of stock
certificates and expenses of delivering such certificates to the purchaser
thereof; expenses of local representation in Massachusetts; expenses of
shareholders' meetings and of preparing, printing and distributing proxy
statements, notices, and reports to shareholders; expenses of preparing and
filing reports and tax returns with federal and state regulatory authorities;
all expenses incurred in complying with all federal and state laws and the laws
of any foreign country applicable to the issue, offer, or sale of shares of the
Fund, including, but not limited to, all costs involved in the registration or
qualification of shares of the Fund for sale in any jurisdiction, the costs of
portfolio pricing services and systems for compliance with blue sky laws, and
all costs involved in preparing, printing and mailing prospectuses and
statements of additional information of the Fund; and all fees, dues and other
expenses incurred by the Trust in connection with the membership of the Trust in
any trade association or other investment company organization. To the extent
that JCC shall perform any of the above described administrative and clerical
functions, including transfer agency, registry, dividend disbursing,
recordkeeping, bookkeeping, accounting and blue sky monitoring and registration
functions, and the preparation of reports and returns, the Trust shall pay to
JCC compensation for, or reimburse JCC for its expenses incurred in connection
with, such services as JCC and the Trust shall agree from time to time, any
other provision of this Agreement notwithstanding.


                                     - 3 -

<PAGE>


     7.   Treatment of Investment Advice. The Trust shall treat the investment
advice and recommendations of JCC as being advisory only, and shall retain full
control over its own investment policies. However, the Trustees may delegate to
the appropriate officers of the Trust, or to a committee of the Trustees, the
power to authorize purchases, sales or other actions affecting the portfolio of
the Fund in the interim between meetings of the Trustees.

     8.   Brokerage Commissions. For purposes of this Agreement, brokerage
commissions paid by the Fund upon the purchase or sale of its portfolio
securities shall be considered a cost of securities of the Fund and shall be
paid by the Fund. JCC is authorized and directed to place Fund portfolio
transactions only with brokers and dealers who render satisfactory service in
the execution of orders at the most favorable prices and at reasonable
commission rates, provided, however, that JCC may pay a broker or dealer an
amount of commission for effecting a securities transaction in excess of the
amount of commission another broker or dealer would have charged for effecting
that transaction if JCC determines in good faith that such amount of commission
was reasonable in relation to the value of the brokerage and research services
provided by such broker or dealer viewed in terms of either that particular
transaction or the overall responsibilities of JCC. JCC is also authorized to
consider sales of Trust shares as a factor in selecting broker-dealers to
execute Fund portfolio transactions. In placing portfolio business with such
broker-dealers, JCC shall seek the best execution of each transaction. Subject
to the terms of this Agreement and the applicable requirements and provisions of
the law, including the Investment Company Act of 1940 and the Securities
Exchange Act of 1934, as amended, and in the event that JCC or an affiliate is
registered as a broker-dealer, JCC may select a broker or dealer with which it
or the Fund is affiliated. JCC or such affiliated broker-dealer may effect or
execute Fund portfolio transactions, whether on a securities exchange or in the
over-the-counter market, and receive separate compensation from the Fund
therefor. Notwithstanding the foregoing, the Trust shall retain the right to
direct the placement of all portfolio transactions, and the Trustees of the
Trust may establish policies or guidelines to be followed by JCC in placing
portfolio transactions for the Trust pursuant to the foregoing provisions. JCC
shall report on the placement of portfolio transactions in the prior fiscal
quarter at each quarterly meeting of such Trustees.

     9.   Termination. This Agreement may be terminated at any time, without
penalty, by the Board of Trustees of the Trust, or by the shareholders of the
Trust acting by vote of at least a majority of its outstanding voting
securities, provided in either case that sixty (60) days advance written notice
of termination be given to JCC at its principal place of business. This
Agreement may be terminated by JCC at any time, without penalty, by giving sixty
(60) days advance written notice of termination to the Trust, addressed to its
principal place of business. The Trust agrees that, consistent with the terms of
the Trust's Declaration of Trust, the Trust shall cease to use the name "Janus"
in connection with the Fund as soon as reasonably practicable following any
termination of this Agreement if JCC does not continue to provide investment
advice to the Fund after such termination.

     10.  Assignment. This Agreement shall terminate automatically in the
event of any assignment of this Agreement.


                                     - 4 -

<PAGE>


     11.  Term. This Agreement shall continue in effect until July 1, 1998,
unless sooner terminated in accordance with its terms, and shall continue in
effect from year to year thereafter only so long as such continuance is
specifically approved at least annually by the vote of a majority of the
Trustees of the Trust who are not parties hereto or interested persons of any
such party, cast in person at a meeting called for the purpose of voting on the
approval of the terms of such renewal, and by either the Board of Trustees of
the Trust or the affirmative vote of a majority of the outstanding voting
securities of the Trust. The annual approvals provided for herein shall be
effective to continue this Agreement from year to year if given within a period
beginning not more than sixty (60) days prior to July 1 of each applicable year,
notwithstanding the fact that more than three hundred sixty-five (365) days may
have elapsed since the date on which such approval was last given.

     12.  Amendments. This Agreement may be amended by the parties only if
such amendment is specifically approved (i) by a majority of the Trustees,
including a majority of the Trustees who are not interested persons (as that
phrase is defined in Section 2(a)(19) of the 1940 Act) of JCC and, if required
by applicable law, (ii) by the affirmative vote of a majority of the outstanding
voting securities of the Fund (as that phrase is defined in Section 2(a)(42) of
the 1940 Act).

     13.  Other Series. The Trustees shall determine the basis for making an
appropriate allocation of the Trust's expenses (other than those directly
attributable to the Fund) between the Fund and the other series of the Trust.

     14.  Limitation of Personal Liability. All the parties hereto
acknowledge and agree that all liabilities of the Trust arising, directly or
indirectly, under this Agreement, of any and every nature whatsoever, shall be
satisfied solely out of the assets of the Fund and that no Trustee, officer or
holder of shares of beneficial interest of the Trust shall be personally liable
for any of the foregoing liabilities. The Trust's Declaration of Trust, as
amended from time to time, is on file in the Office of the Secretary of State of
the Commonwealth of Massachusetts. Such Declaration of Trust describes in detail
the respective responsibilities and limitations on liability of the Trustees,
officers and holders of shares of beneficial interest of the Trust.

     15.  Limitation of Liability of JCC. JCC shall not be liable for any
error of judgment or mistake of law or for any loss arising out of any
investment or for any act or omission taken with respect to the Trust, except
for willful misfeasance, bad faith or gross negligence in the performance of its
duties, or by reason of reckless disregard of its obligations and duties
hereunder and except to the extent otherwise provided by law. As used in this
Section 15, "JCC" shall include any affiliate of JCC performing services for the
Trust contemplated hereunder and directors, officers and employees of JCC and
such affiliates.

     16.  Activities of JCC. The services of JCC to the Trust hereunder are
not to be deemed to be exclusive, and JCC and its affiliates are free to render
services to other parties. It is understood that trustees, officers and
shareholders of the Trust are or may become interested in JCC as directors,


                                     - 5 -

<PAGE>


officers and shareholders of JCC, that directors, officers, employees and
shareholders of JCC are or may become similarly interested in the Trust, and
that JCC may become interested in the Trust as a shareholder or otherwise.

     17.  Certain Definitions. The terms "vote of a majority of the
outstanding voting securities", "assignment" and "interested persons" when used
herein, shall have the respective meanings specified in the 1940 Act, as now in
effect or hereafter amended, and the rules and regulations thereunder, subject
to such orders, exemptions and interpretations as may be issued by the
Securities and Exchange Commission under said Act and as may be then in effect.

     IN WITNESS WHEREOF, the parties have caused their duly authorized
officers to execute this Investment Advisory Agreement as of this 1st day of
July, 1997.


                                        JANUS CAPITAL CORPORATION



                                        By: /s/ Steven R. Goodbarn
                                            Steven R. Goodbarn, Vice President


                                        JANUS INVESTMENT FUND



                                         By: /s/ Thomas H. Bailey
                                             Thomas H. Bailey, President


                                     - 6 -





                                                                 EXHIBIT 5(e)


                             JANUS INVESTMENT FUND

                         INVESTMENT ADVISORY AGREEMENT

                             JANUS ENTERPRISE FUND


     THIS INVESTMENT ADVISORY AGREEMENT (the "Agreement") is made this 1st
day of July, 1997, between JANUS INVESTMENT FUND, a Massachusetts business trust
(the "Trust"), and JANUS CAPITAL CORPORATION, a Colorado corporation ("JCC").

                              W I T N E S S E T H:

     WHEREAS, the Trust is registered as an open-end management investment
company under the Investment Company Act of 1940, as amended (the "1940 Act"),
and has registered its shares for public offering under the Securities Act of
1933, as amended (the "1933 Act"); and

     WHEREAS, the Trust is authorized to create separate funds, each with
its own separate investment portfolio of which the beneficial interests are
represented by a separate series of shares; one of such funds created by the
Trust being designated as the Janus Enterprise Fund (the "Fund"); and

     WHEREAS, the Trust and JCC deem it mutually advantageous that JCC
should assist the Board of Trustees and officers of the Trust in the management
of the securities portfolio of the Fund.

     NOW, THEREFORE, the parties agree as follows:

     1.   Investment Advisory Services. JCC shall furnish continuous advice
and recommendations to the Fund as to the acquisition, holding, or disposition
of any or all of the securities or other assets which the Fund may own or
contemplate acquiring from time to time. JCC shall give due consideration to the
investment policies and restrictions and the other statements concerning the
Fund in the Trust's declaration of trust, bylaws, and registration statements
under the 1940 Act and the 1933 Act, and to the provisions of the Internal
Revenue Code, as amended from time to time, applicable to the Fund as a
regulated investment company. In addition, JCC shall cause its officers to
attend meetings and furnish oral or written reports, as the Trust may reasonably
require, in order to keep the Board of Trustees and appropriate officers of the
Trust fully informed as to the condition of the investment portfolio of the
Fund, the investment recommendations of JCC, and the investment considerations
which have given rise to those recommendations. JCC shall supervise the purchase
and sale of securities as directed by the appropriate officers of the Trust.

     2.   Other Services. JCC is hereby authorized (to the extent the Trust
has not otherwise contracted) but not obligated (to the extent it so notifies
the Board of Trustees at least 60 days in advance), to perform (or arrange for
the performance by affiliates of) the management and


                                     - 1 -

<PAGE>


administrative services necessary for the operation of the Fund. JCC is
specifically authorized, on behalf of the Trust, to conduct relations with
custodians, depositories, transfer and pricing agents, accountants, attorneys,
underwriters, brokers and dealers, corporate fiduciaries, insurers, banks and
such other persons in any such other capacity deemed by JCC to be necessary or
desirable. JCC shall generally monitor and report to Fund officers the Fund's
compliance with investment policies and restrictions as set forth in the
currently effective prospectus and statement of additional information relating
to the shares of the Fund under the Securities Act of 1933, as amended. JCC
shall make reports to the Trust's Board of Trustees of its performance of
services hereunder upon request therefor and furnish advice and recommendations
with respect to such other aspects of the business and affairs of the Fund as it
shall determine to be desirable. JCC is also authorized, subject to review by
the Board of Trustees, to furnish such other services as the Adviser shall from
time to time determine to be necessary or useful to perform the services
contemplated by this Agreement.

     3.   Obligations of Trust. The Trust shall have the following obligations
under this Agreement:

          (a)  to keep JCC continuously and fully informed as to the
               composition of its investment portfolio and the
               nature of all of its assets and liabilities from time
               to time;

          (b)  to furnish JCC with a certified copy of any financial
               statement or report prepared for it by certified or
               independent public accountants and with copies of any
               financial statements or reports made to its
               shareholders or to any governmental body or
               securities exchange;

          (c)  to furnish JCC with any further materials or
               information which JCC may reasonably request to
               enable it to perform its function under this
               Agreement; and

          (d)  to compensate JCC for its services and reimburse JCC
               for its expenses incurred hereunder in accordance
               with the provisions hereof.

     4.   Compensation. The Trust shall pay to JCC for its investment advisory
services a fee, calculated and payable for each day that this Agreement is in
effect, of 1/365 of 0.75% of the first $300,000,000 of the daily closing net
asset value of the Fund, plus 1/365 of 0.70% of the next $200,000,000 of the
daily closing net asset value of the Fund, plus 1/365 of 0.65% of the daily
closing net asset value of the Fund in excess of $500,000,000. The fee shall be
paid monthly.

     5.   Expenses Borne by JCC. In addition to the expenses which JCC may
incur in the performance of its investment advisory functions under this
Agreement, and the expenses which it may expressly undertake to incur and pay
under other agreements with the Trust or otherwise, JCC shall incur and pay the
following expenses relating to the Fund's operations without reimbursement from
the Fund:


                                     - 2 -

<PAGE>


          (a)  Reasonable compensation, fees and related expenses of
               the Trust's officers and its Trustees (the
               "Trustees"), except for such Trustees who are not
               interested persons of JCC;

          (b)  Rental of offices of the Trust; and

          (c)  All expenses of promoting the sale of shares of the Fund, other
               than expenses incurred in complying with federal and state laws 
               and the law of any foreign country or territory or other
               jurisdiction applicable to the issue, offer or sale of shares of
               the Fund including without limitation registration fees and 
               costs, the costs of preparing the Fund's registration statement
               and amendments thereto, and the costs and expenses of preparing,
               printing, and mailing prospectuses (and statements of additional
               information) to persons other than shareholders of the Fund.

     6.   Expenses Borne by the Trust. The Trust assumes and shall pay all
expenses incidental to its organization, operations and business not
specifically assumed or agreed to be paid by JCC pursuant to Sections 2 and 5
hereof, including, but not limited to, investment adviser fees; any
compensation, fees, or reimbursements which the Trust pays to its Trustees who
are not interested persons of JCC; compensation of the Fund's custodian,
transfer agent, registrar and dividend disbursing agent; legal, accounting,
audit and printing expenses; administrative, clerical, recordkeeping and
bookkeeping expenses; brokerage commissions and all other expenses in connection
with execution of portfolio transactions (including any appropriate commissions
paid to JCC or its affiliates for effecting exchange listed, over-the-counter or
other securities transactions); interest; all federal, state and local taxes
(including stamp, excise, income and franchise taxes); costs of stock
certificates and expenses of delivering such certificates to the purchaser
thereof; expenses of local representation in Massachusetts; expenses of
shareholders' meetings and of preparing, printing and distributing proxy
statements, notices, and reports to shareholders; expenses of preparing and
filing reports and tax returns with federal and state regulatory authorities;
all expenses incurred in complying with all federal and state laws and the laws
of any foreign country applicable to the issue, offer, or sale of shares of the
Fund, including, but not limited to, all costs involved in the registration or
qualification of shares of the Fund for sale in any jurisdiction, the costs of
portfolio pricing services and systems for compliance with blue sky laws, and
all costs involved in preparing, printing and mailing prospectuses and
statements of additional information of the Fund; and all fees, dues and other
expenses incurred by the Trust in connection with the membership of the Trust in
any trade association or other investment company organization. To the extent
that JCC shall perform any of the above described administrative and clerical
functions, including transfer agency, registry, dividend disbursing,
recordkeeping, bookkeeping, accounting and blue sky monitoring and registration
functions, and the preparation of reports and returns, the Trust shall pay to
JCC compensation for, or reimburse JCC for its expenses incurred in connection
with, such services as JCC and the Trust shall agree from time to time, any
other provision of this Agreement notwithstanding.


                                     - 3 -

<PAGE>


     7.   Treatment of Investment Advice. The Trust shall treat the investment
advice and recommendations of JCC as being advisory only, and shall retain full
control over its own investment policies. However, the Trustees may delegate to
the appropriate officers of the Trust, or to a committee of the Trustees, the
power to authorize purchases, sales or other actions affecting the portfolio of
the Fund in the interim between meetings of the Trustees.

     8.   Brokerage Commissions. For purposes of this Agreement, brokerage
commissions paid by the Fund upon the purchase or sale of its portfolio
securities shall be considered a cost of securities of the Fund and shall be
paid by the Fund. JCC is authorized and directed to place Fund portfolio
transactions only with brokers and dealers who render satisfactory service in
the execution of orders at the most favorable prices and at reasonable
commission rates, provided, however, that JCC may pay a broker or dealer an
amount of commission for effecting a securities transaction in excess of the
amount of commission another broker or dealer would have charged for effecting
that transaction if JCC determines in good faith that such amount of commission
was reasonable in relation to the value of the brokerage and research services
provided by such broker or dealer viewed in terms of either that particular
transaction or the overall responsibilities of JCC. JCC is also authorized to
consider sales of Trust shares as a factor in selecting broker-dealers to
execute Fund portfolio transactions. In placing portfolio business with such
broker-dealers, JCC shall seek the best execution of each transaction. Subject
to the terms of this Agreement and the applicable requirements and provisions of
the law, including the Investment Company Act of 1940 and the Securities
Exchange Act of 1934, as amended, and in the event that JCC or an affiliate is
registered as a broker-dealer, JCC may select a broker or dealer with which it
or the Fund is affiliated. JCC or such affiliated broker-dealer may effect or
execute Fund portfolio transactions, whether on a securities exchange or in the
over-the-counter market, and receive separate compensation from the Fund
therefor. Notwithstanding the foregoing, the Trust shall retain the right to
direct the placement of all portfolio transactions, and the Trustees of the
Trust may establish policies or guidelines to be followed by JCC in placing
portfolio transactions for the Trust pursuant to the foregoing provisions. JCC
shall report on the placement of portfolio transactions in the prior fiscal
quarter at each quarterly meeting of such Trustees.

     9.   Termination. This Agreement may be terminated at any time, without
penalty, by the Board of Trustees of the Trust, or by the shareholders of the
Trust acting by vote of at least a majority of its outstanding voting
securities, provided in either case that sixty (60) days advance written notice
of termination be given to JCC at its principal place of business. This
Agreement may be terminated by JCC at any time, without penalty, by giving sixty
(60) days advance written notice of termination to the Trust, addressed to its
principal place of business. The Trust agrees that, consistent with the terms of
the Trust's Declaration of Trust, the Trust shall cease to use the name "Janus"
in connection with the Fund as soon as reasonably practicable following any
termination of this Agreement if JCC does not continue to provide investment
advice to the Fund after such termination.

     10.  Assignment. This Agreement shall terminate automatically in the
event of any assignment of this Agreement.


                                     - 4 -

<PAGE>


     11.  Term. This Agreement shall continue in effect until July 1, 1998,
unless sooner terminated in accordance with its terms, and shall continue in
effect from year to year thereafter only so long as such continuance is
specifically approved at least annually by the vote of a majority of the
Trustees of the Trust who are not parties hereto or interested persons of any
such party, cast in person at a meeting called for the purpose of voting on the
approval of the terms of such renewal, and by either the Board of Trustees of
the Trust or the affirmative vote of a majority of the outstanding voting
securities of the Trust. The annual approvals provided for herein shall be
effective to continue this Agreement from year to year if given within a period
beginning not more than sixty (60) days prior to July 1 of each applicable year,
notwithstanding the fact that more than three hundred sixty-five (365) days may
have elapsed since the date on which such approval was last given.

     12.  Amendments. This Agreement may be amended by the parties only if
such amendment is specifically approved (i) by a majority of the Trustees,
including a majority of the Trustees who are not interested persons (as that
phrase is defined in Section 2(a)(19) of the 1940 Act) of JCC and, if required
by applicable law, (ii) by the affirmative vote of a majority of the outstanding
voting securities of the Fund (as that phrase is defined in Section 2(a)(42) of
the 1940 Act).

     13.  Other Series. The Trustees shall determine the basis for making an
appropriate allocation of the Trust's expenses (other than those directly
attributable to the Fund) between the Fund and the other series of the Trust.

     14.  Limitation of Personal Liability. All the parties hereto
acknowledge and agree that all liabilities of the Trust arising, directly or
indirectly, under this Agreement, of any and every nature whatsoever, shall be
satisfied solely out of the assets of the Fund and that no Trustee, officer or
holder of shares of beneficial interest of the Trust shall be personally liable
for any of the foregoing liabilities. The Trust's Declaration of Trust, as
amended from time to time, is on file in the Office of the Secretary of State of
the Commonwealth of Massachusetts. Such Declaration of Trust describes in detail
the respective responsibilities and limitations on liability of the Trustees,
officers and holders of shares of beneficial interest of the Trust.

     15.  Limitation of Liability of JCC. JCC shall not be liable for any
error of judgment or mistake of law or for any loss arising out of any
investment or for any act or omission taken with respect to the Trust, except
for willful misfeasance, bad faith or gross negligence in the performance of its
duties, or by reason of reckless disregard of its obligations and duties
hereunder and except to the extent otherwise provided by law. As used in this
Section 15, "JCC" shall include any affiliate of JCC performing services for the
Trust contemplated hereunder and directors, officers and employees of JCC and
such affiliates.

     16.  Activities of JCC. The services of JCC to the Trust hereunder are
not to be deemed to be exclusive, and JCC and its affiliates are free to render
services to other parties. It is understood that trustees, officers and
shareholders of the Trust are or may become interested in JCC as directors,


                                     - 5 -

<PAGE>


officers and shareholders of JCC, that directors, officers, employees and
shareholders of JCC are or may become similarly interested in the Trust, and
that JCC may become interested in the Trust as a shareholder or otherwise.

     17.  Certain Definitions. The terms "vote of a majority of the
outstanding voting securities", "assignment" and "interested persons" when used
herein, shall have the respective meanings specified in the 1940 Act, as now in
effect or hereafter amended, and the rules and regulations thereunder, subject
to such orders, exemptions and interpretations as may be issued by the
Securities and Exchange Commission under said Act and as may be then in effect.

     IN WITNESS WHEREOF, the parties have caused their duly authorized
officers to execute this Investment Advisory Agreement as of this 1st day of
July, 1997.


                                        JANUS CAPITAL CORPORATION



                                        By: /s/ Steven R. Goodbarn
                                            Steven R. Goodbarn, Vice President


                                        JANUS INVESTMENT FUND



                                         By: /s/ Thomas H. Bailey
                                             Thomas H. Bailey, President


                                     - 6 -

<PAGE>




                             JANUS INVESTMENT FUND

                         INVESTMENT ADVISORY AGREEMENT

                              JANUS BALANCED FUND


     THIS INVESTMENT ADVISORY AGREEMENT (the "Agreement") is made this 1st
day of July, 1997, between JANUS INVESTMENT FUND, a Massachusetts business trust
(the "Trust"), and JANUS CAPITAL CORPORATION, a Colorado corporation ("JCC").

                              W I T N E S S E T H:

     WHEREAS, the Trust is registered as an open-end management investment
company under the Investment Company Act of 1940, as amended (the "1940 Act"),
and has registered its shares for public offering under the Securities Act of
1933, as amended (the "1933 Act"); and

     WHEREAS, the Trust is authorized to create separate funds, each with
its own separate investment portfolio of which the beneficial interests are
represented by a separate series of shares; one of such funds created by the
Trust being designated as the Janus Balanced Fund (the "Fund"); and

     WHEREAS, the Trust and JCC deem it mutually advantageous that JCC
should assist the Board of Trustees and officers of the Trust in the management
of the securities portfolio of the Fund.

     NOW, THEREFORE, the parties agree as follows:

     1.   Investment Advisory Services. JCC shall furnish continuous advice
and recommendations to the Fund as to the acquisition, holding, or disposition
of any or all of the securities or other assets which the Fund may own or
contemplate acquiring from time to time. JCC shall give due consideration to the
investment policies and restrictions and the other statements concerning the
Fund in the Trust's declaration of trust, bylaws, and registration statements
under the 1940 Act and the 1933 Act, and to the provisions of the Internal
Revenue Code, as amended from time to time, applicable to the Fund as a
regulated investment company. In addition, JCC shall cause its officers to
attend meetings and furnish oral or written reports, as the Trust may reasonably
require, in order to keep the Board of Trustees and appropriate officers of the
Trust fully informed as to the condition of the investment portfolio of the
Fund, the investment recommendations of JCC, and the investment considerations
which have given rise to those recommendations. JCC shall supervise the purchase
and sale of securities as directed by the appropriate officers of the Trust.

     2.   Other Services. JCC is hereby authorized (to the extent the Trust
has not otherwise contracted) but not obligated (to the extent it so notifies
the Board of Trustees at least 60 days in advance), to perform (or arrange for
the performance by affiliates of) the management and


                                     - 1 -

<PAGE>


administrative services necessary for the operation of the Fund. JCC is
specifically authorized, on behalf of the Trust, to conduct relations with
custodians, depositories, transfer and pricing agents, accountants, attorneys,
underwriters, brokers and dealers, corporate fiduciaries, insurers, banks and
such other persons in any such other capacity deemed by JCC to be necessary or
desirable. JCC shall generally monitor and report to Fund officers the Fund's
compliance with investment policies and restrictions as set forth in the
currently effective prospectus and statement of additional information relating
to the shares of the Fund under the Securities Act of 1933, as amended. JCC
shall make reports to the Trust's Board of Trustees of its performance of
services hereunder upon request therefor and furnish advice and recommendations
with respect to such other aspects of the business and affairs of the Fund as it
shall determine to be desirable. JCC is also authorized, subject to review by
the Board of Trustees, to furnish such other services as the Adviser shall from
time to time determine to be necessary or useful to perform the services
contemplated by this Agreement.

     3.   Obligations of Trust. The Trust shall have the following obligations
under this Agreement:

          (a)  to keep JCC continuously and fully informed as to the
               composition of its investment portfolio and the
               nature of all of its assets and liabilities from time
               to time;

          (b)  to furnish JCC with a certified copy of any financial
               statement or report prepared for it by certified or
               independent public accountants and with copies of any
               financial statements or reports made to its
               shareholders or to any governmental body or
               securities exchange;

          (c)  to furnish JCC with any further materials or
               information which JCC may reasonably request to
               enable it to perform its function under this
               Agreement; and

          (d)  to compensate JCC for its services and reimburse JCC
               for its expenses incurred hereunder in accordance
               with the provisions hereof.

     4.   Compensation. The Trust shall pay to JCC for its investment advisory
services a fee, calculated and payable for each day that this Agreement is in
effect, of 1/365 of 0.75% of the first $300,000,000 of the daily closing net
asset value of the Fund, plus 1/365 of 0.70% of the next $200,000,000 of the
daily closing net asset value of the Fund, plus 1/365 of 0.65% of the daily
closing net asset value of the Fund in excess of $500,000,000. The fee shall be
paid monthly.

     5.   Expenses Borne by JCC. In addition to the expenses which JCC may
incur in the performance of its investment advisory functions under this
Agreement, and the expenses which it may expressly undertake to incur and pay
under other agreements with the Trust or otherwise, JCC shall incur and pay the
following expenses relating to the Fund's operations without reimbursement from
the Fund:


                                     - 2 -

<PAGE>


          (a)  Reasonable compensation, fees and related expenses of
               the Trust's officers and its Trustees (the
               "Trustees"), except for such Trustees who are not
               interested persons of JCC;

          (b)  Rental of offices of the Trust; and

          (c)  All expenses of promoting the sale of shares of the Fund, other
               than expenses incurred in complying with federal and state laws
               and the law of any foreign country or territory or other
               jurisdiction applicable to the issue, offer or sale of shares
               of the Fund including without limitation registration fees and 
               costs, the costs of preparing the Fund's registration statement
               and amendments thereto, and the costs and expenses of preparing,
               printing, and mailing prospectuses (and statements of additional
               information) to persons other than shareholders of the Fund.

     6.   Expenses Borne by the Trust. The Trust assumes and shall pay all
expenses incidental to its organization, operations and business not
specifically assumed or agreed to be paid by JCC pursuant to Sections 2 and 5
hereof, including, but not limited to, investment adviser fees; any
compensation, fees, or reimbursements which the Trust pays to its Trustees who
are not interested persons of JCC; compensation of the Fund's custodian,
transfer agent, registrar and dividend disbursing agent; legal, accounting,
audit and printing expenses; administrative, clerical, recordkeeping and
bookkeeping expenses; brokerage commissions and all other expenses in connection
with execution of portfolio transactions (including any appropriate commissions
paid to JCC or its affiliates for effecting exchange listed, over-the-counter or
other securities transactions); interest; all federal, state and local taxes
(including stamp, excise, income and franchise taxes); costs of stock
certificates and expenses of delivering such certificates to the purchaser
thereof; expenses of local representation in Massachusetts; expenses of
shareholders' meetings and of preparing, printing and distributing proxy
statements, notices, and reports to shareholders; expenses of preparing and
filing reports and tax returns with federal and state regulatory authorities;
all expenses incurred in complying with all federal and state laws and the laws
of any foreign country applicable to the issue, offer, or sale of shares of the
Fund, including, but not limited to, all costs involved in the registration or
qualification of shares of the Fund for sale in any jurisdiction, the costs of
portfolio pricing services and systems for compliance with blue sky laws, and
all costs involved in preparing, printing and mailing prospectuses and
statements of additional information of the Fund; and all fees, dues and other
expenses incurred by the Trust in connection with the membership of the Trust in
any trade association or other investment company organization. To the extent
that JCC shall perform any of the above described administrative and clerical
functions, including transfer agency, registry, dividend disbursing,
recordkeeping, bookkeeping, accounting and blue sky monitoring and registration
functions, and the preparation of reports and returns, the Trust shall pay to
JCC compensation for, or reimburse JCC for its expenses incurred in connection
with, such services as JCC and the Trust shall agree from time to time, any
other provision of this Agreement notwithstanding.


                                     - 3 -

<PAGE>


     7.   Treatment of Investment Advice. The Trust shall treat the investment
advice and recommendations of JCC as being advisory only, and shall retain full
control over its own investment policies. However, the Trustees may delegate to
the appropriate officers of the Trust, or to a committee of the Trustees, the
power to authorize purchases, sales or other actions affecting the portfolio of
the Fund in the interim between meetings of the Trustees.

     8.   Brokerage Commissions. For purposes of this Agreement, brokerage
commissions paid by the Fund upon the purchase or sale of its portfolio
securities shall be considered a cost of securities of the Fund and shall be
paid by the Fund. JCC is authorized and directed to place Fund portfolio
transactions only with brokers and dealers who render satisfactory service in
the execution of orders at the most favorable prices and at reasonable
commission rates, provided, however, that JCC may pay a broker or dealer an
amount of commission for effecting a securities transaction in excess of the
amount of commission another broker or dealer would have charged for effecting
that transaction if JCC determines in good faith that such amount of commission
was reasonable in relation to the value of the brokerage and research services
provided by such broker or dealer viewed in terms of either that particular
transaction or the overall responsibilities of JCC. JCC is also authorized to
consider sales of Trust shares as a factor in selecting broker-dealers to
execute Fund portfolio transactions. In placing portfolio business with such
broker-dealers, JCC shall seek the best execution of each transaction. Subject
to the terms of this Agreement and the applicable requirements and provisions of
the law, including the Investment Company Act of 1940 and the Securities
Exchange Act of 1934, as amended, and in the event that JCC or an affiliate is
registered as a broker-dealer, JCC may select a broker or dealer with which it
or the Fund is affiliated. JCC or such affiliated broker-dealer may effect or
execute Fund portfolio transactions, whether on a securities exchange or in the
over-the-counter market, and receive separate compensation from the Fund
therefor. Notwithstanding the foregoing, the Trust shall retain the right to
direct the placement of all portfolio transactions, and the Trustees of the
Trust may establish policies or guidelines to be followed by JCC in placing
portfolio transactions for the Trust pursuant to the foregoing provisions. JCC
shall report on the placement of portfolio transactions in the prior fiscal
quarter at each quarterly meeting of such Trustees.

     9.   Termination. This Agreement may be terminated at any time, without
penalty, by the Board of Trustees of the Trust, or by the shareholders of the
Trust acting by vote of at least a majority of its outstanding voting
securities, provided in either case that sixty (60) days advance written notice
of termination be given to JCC at its principal place of business. This
Agreement may be terminated by JCC at any time, without penalty, by giving sixty
(60) days advance written notice of termination to the Trust, addressed to its
principal place of business. The Trust agrees that, consistent with the terms of
the Trust's Declaration of Trust, the Trust shall cease to use the name "Janus"
in connection with the Fund as soon as reasonably practicable following any
termination of this Agreement if JCC does not continue to provide investment
advice to the Fund after such termination.

     10.  Assignment. This Agreement shall terminate automatically in the
event of any assignment of this Agreement.


                                     - 4 -

<PAGE>


     11.  Term. This Agreement shall continue in effect until July 1, 1998,
unless sooner terminated in accordance with its terms, and shall continue in
effect from year to year thereafter only so long as such continuance is
specifically approved at least annually by the vote of a majority of the
Trustees of the Trust who are not parties hereto or interested persons of any
such party, cast in person at a meeting called for the purpose of voting on the
approval of the terms of such renewal, and by either the Board of Trustees of
the Trust or the affirmative vote of a majority of the outstanding voting
securities of the Trust. The annual approvals provided for herein shall be
effective to continue this Agreement from year to year if given within a period
beginning not more than sixty (60) days prior to July 1 of each applicable year,
notwithstanding the fact that more than three hundred sixty-five (365) days may
have elapsed since the date on which such approval was last given.

     12.  Amendments. This Agreement may be amended by the parties only if
such amendment is specifically approved (i) by a majority of the Trustees,
including a majority of the Trustees who are not interested persons (as that
phrase is defined in Section 2(a)(19) of the 1940 Act) of JCC and, if required
by applicable law, (ii) by the affirmative vote of a majority of the outstanding
voting securities of the Fund (as that phrase is defined in Section 2(a)(42) of
the 1940 Act).

     13.  Other Series. The Trustees shall determine the basis for making an
appropriate allocation of the Trust's expenses (other than those directly
attributable to the Fund) between the Fund and the other series of the Trust.

     14.  Limitation of Personal Liability. All the parties hereto
acknowledge and agree that all liabilities of the Trust arising, directly or
indirectly, under this Agreement, of any and every nature whatsoever, shall be
satisfied solely out of the assets of the Fund and that no Trustee, officer or
holder of shares of beneficial interest of the Trust shall be personally liable
for any of the foregoing liabilities. The Trust's Declaration of Trust, as
amended from time to time, is on file in the Office of the Secretary of State of
the Commonwealth of Massachusetts. Such Declaration of Trust describes in detail
the respective responsibilities and limitations on liability of the Trustees,
officers and holders of shares of beneficial interest of the Trust.

     15.  Limitation of Liability of JCC. JCC shall not be liable for any
error of judgment or mistake of law or for any loss arising out of any
investment or for any act or omission taken with respect to the Trust, except
for willful misfeasance, bad faith or gross negligence in the performance of its
duties, or by reason of reckless disregard of its obligations and duties
hereunder and except to the extent otherwise provided by law. As used in this
Section 15, "JCC" shall include any affiliate of JCC performing services for the
Trust contemplated hereunder and directors, officers and employees of JCC and
such affiliates.

     16.  Activities of JCC. The services of JCC to the Trust hereunder are
not to be deemed to be exclusive, and JCC and its affiliates are free to render
services to other parties. It is understood that trustees, officers and
shareholders of the Trust are or may become interested in JCC as directors,


                                     - 5 -

<PAGE>


officers and shareholders of JCC, that directors, officers, employees and
shareholders of JCC are or may become similarly interested in the Trust, and
that JCC may become interested in the Trust as a shareholder or otherwise.

     17.  Certain Definitions. The terms "vote of a majority of the
outstanding voting securities", "assignment" and "interested persons" when used
herein, shall have the respective meanings specified in the 1940 Act, as now in
effect or hereafter amended, and the rules and regulations thereunder, subject
to such orders, exemptions and interpretations as may be issued by the
Securities and Exchange Commission under said Act and as may be then in effect.

     IN WITNESS WHEREOF, the parties have caused their duly authorized
officers to execute this Investment Advisory Agreement as of this 1st day of
July, 1997.


                                        JANUS CAPITAL CORPORATION



                                         By: /s/ Steven R. Goodbarn
                                             Steven R. Goodbarn, Vice President


                                        JANUS INVESTMENT FUND



                                        By: /s/ Thomas H. Bailey
                                            Thomas H. Bailey, President



                                     - 6 -

<PAGE>




                             JANUS INVESTMENT FUND

                          INVESTMENT ADVISORY AGREEMENT

                           JANUS SHORT-TERM BOND FUND


     THIS INVESTMENT ADVISORY AGREEMENT (the "Agreement") is made this 1st
day of July, 1997, between JANUS INVESTMENT FUND, a Massachusetts business trust
(the "Trust"), and JANUS CAPITAL CORPORATION, a Colorado corporation ("JCC").

                              W I T N E S S E T H:

     WHEREAS, the Trust is registered as an open-end management investment
company under the Investment Company Act of 1940, as amended (the "1940 Act"),
and has registered its shares for public offering under the Securities Act of
1933, as amended (the "1933 Act"); and

     WHEREAS, the Trust is authorized to create separate funds, each with
its own separate investment portfolio of which the beneficial interests are
represented by a separate series of shares; one of such funds created by the
Trust being designated as the Janus Short-Term Bond Fund (the "Fund"); and

     WHEREAS, the Trust and JCC deem it mutually advantageous that JCC
should assist the Board of Trustees and officers of the Trust in the management
of the securities portfolio of the Fund.

     NOW, THEREFORE, the parties agree as follows:

     1.   Investment Advisory Services. JCC shall furnish continuous advice
and recommendations to the Fund as to the acquisition, holding, or disposition
of any or all of the securities or other assets which the Fund may own or
contemplate acquiring from time to time. JCC shall give due consideration to the
investment policies and restrictions and the other statements concerning the
Fund in the Trust's declaration of trust, bylaws, and registration statements
under the 1940 Act and the 1933 Act, and to the provisions of the Internal
Revenue Code, as amended from time to time, applicable to the Fund as a
regulated investment company. In addition, JCC shall cause its officers to
attend meetings and furnish oral or written reports, as the Trust may reasonably
require, in order to keep the Board of Trustees and appropriate officers of the
Trust fully informed as to the condition of the investment portfolio of the
Fund, the investment recommendations of JCC, and the investment considerations
which have given rise to those recommendations. JCC shall supervise the purchase
and sale of securities as directed by the appropriate officers of the Trust.

     2.   Other Services. JCC is hereby authorized (to the extent the Trust
has not otherwise contracted) but not obligated (to the extent it so notifies
the Board of Trustees at least 60 days in advance), to perform (or arrange for
the performance by affiliates of) the management and


                                     - 1 -

<PAGE>


administrative services necessary for the operation of the Fund. JCC is
specifically authorized, on behalf of the Trust, to conduct relations with
custodians, depositories, transfer and pricing agents, accountants, attorneys,
underwriters, brokers and dealers, corporate fiduciaries, insurers, banks and
such other persons in any such other capacity deemed by JCC to be necessary or
desirable. JCC shall generally monitor and report to Fund officers the Fund's
compliance with investment policies and restrictions as set forth in the
currently effective prospectus and statement of additional information relating
to the shares of the Fund under the Securities Act of 1933, as amended. JCC
shall make reports to the Trust's Board of Trustees of its performance of
services hereunder upon request therefor and furnish advice and recommendations
with respect to such other aspects of the business and affairs of the Fund as it
shall determine to be desirable. JCC is also authorized, subject to review by
the Board of Trustees, to furnish such other services as the Adviser shall from
time to time determine to be necessary or useful to perform the services
contemplated by this Agreement.

     3.   Obligations of Trust. The Trust shall have the following obligations
under this Agreement:

          (a)  to keep JCC continuously and fully informed as to the
               composition of its investment portfolio and the
               nature of all of its assets and liabilities from time
               to time;

          (b)  to furnish JCC with a certified copy of any financial
               statement or report prepared for it by certified or
               independent public accountants and with copies of any
               financial statements or reports made to its
               shareholders or to any governmental body or
               securities exchange;

          (c)  to furnish JCC with any further materials or
               information which JCC may reasonably request to
               enable it to perform its function under this
               Agreement; and

          (d)  to compensate JCC for its services and reimburse JCC
               for its expenses incurred hereunder in accordance
               with the provisions hereof.

     4.   Compensation. The Trust shall pay to JCC for its investment advisory
services a fee, calculated and payable for each day that this Agreement is in
effect, of 1/365 of .65% of the first $300,000,000 of the daily closing net
asset value of the Fund, plus 1/365 of 0.55% of the daily closing net asset
value of the Fund in excess of $300,000,000. The fee shall be paid monthly.

     5.   Expenses Borne by JCC. In addition to the expenses which JCC may
incur in the performance of its investment advisory functions under this
Agreement, and the expenses which it may expressly undertake to incur and pay
under other agreements with the Trust or otherwise, JCC shall incur and pay the
following expenses relating to the Fund's operations without reimbursement from
the Fund:


                                     - 2 -

<PAGE>


          (a)  Reasonable compensation, fees and related expenses of
               the Trust's officers and its Trustees (the
               "Trustees"), except for such Trustees who are not
               interested persons of JCC;

          (b)  Rental of offices of the Trust; and

          (c)  All expenses of promoting the sale of shares of the Fund, other
               than expenses incurred in complying with federal and state laws
               and the law of any foreign country or territory or other
               jurisdiction applicable to the issue, offer or sale of shares of
               the Fund including without limitation registration fees and 
               costs, the costs of preparing the Fund's registration statement
               and amendments thereto, and the costs and expenses of preparing,
               printing, and mailing prospectuses (and statements of additional
               information) to persons other than shareholders of the Fund.

     6.   Expenses Borne by the Trust. The Trust assumes and shall pay all
expenses incidental to its organization, operations and business not
specifically assumed or agreed to be paid by JCC pursuant to Sections 2 and 5
hereof, including, but not limited to, investment adviser fees; any
compensation, fees, or reimbursements which the Trust pays to its Trustees who
are not interested persons of JCC; compensation of the Fund's custodian,
transfer agent, registrar and dividend disbursing agent; legal, accounting,
audit and printing expenses; administrative, clerical, recordkeeping and
bookkeeping expenses; brokerage commissions and all other expenses in connection
with execution of portfolio transactions (including any appropriate commissions
paid to JCC or its affiliates for effecting exchange listed, over-the-counter or
other securities transactions); interest; all federal, state and local taxes
(including stamp, excise, income and franchise taxes); costs of stock
certificates and expenses of delivering such certificates to the purchaser
thereof; expenses of local representation in Massachusetts; expenses of
shareholders' meetings and of preparing, printing and distributing proxy
statements, notices, and reports to shareholders; expenses of preparing and
filing reports and tax returns with federal and state regulatory authorities;
all expenses incurred in complying with all federal and state laws and the laws
of any foreign country applicable to the issue, offer, or sale of shares of the
Fund, including, but not limited to, all costs involved in the registration or
qualification of shares of the Fund for sale in any jurisdiction, the costs of
portfolio pricing services and systems for compliance with blue sky laws, and
all costs involved in preparing, printing and mailing prospectuses and
statements of additional information of the Fund; and all fees, dues and other
expenses incurred by the Trust in connection with the membership of the Trust in
any trade association or other investment company organization. To the extent
that JCC shall perform any of the above described administrative and clerical
functions, including transfer agency, registry, dividend disbursing,
recordkeeping, bookkeeping, accounting and blue sky monitoring and registration
functions, and the preparation of reports and returns, the Trust shall pay to
JCC compensation for, or reimburse JCC for its expenses incurred in connection
with, such services as JCC and the Trust shall agree from time to time, any
other provision of this Agreement notwithstanding.



                                     - 3 -

<PAGE>


     7.   Treatment of Investment Advice. The Trust shall treat the investment
advice and recommendations of JCC as being advisory only, and shall retain full
control over its own investment policies. However, the Trustees may delegate to
the appropriate officers of the Trust, or to a committee of the Trustees, the
power to authorize purchases, sales or other actions affecting the portfolio of
the Fund in the interim between meetings of the Trustees.

     8.   Brokerage Commissions. For purposes of this Agreement, brokerage
commissions paid by the Fund upon the purchase or sale of its portfolio
securities shall be considered a cost of securities of the Fund and shall be
paid by the Fund. JCC is authorized and directed to place Fund portfolio
transactions only with brokers and dealers who render satisfactory service in
the execution of orders at the most favorable prices and at reasonable
commission rates, provided, however, that JCC may pay a broker or dealer an
amount of commission for effecting a securities transaction in excess of the
amount of commission another broker or dealer would have charged for effecting
that transaction if JCC determines in good faith that such amount of commission
was reasonable in relation to the value of the brokerage and research services
provided by such broker or dealer viewed in terms of either that particular
transaction or the overall responsibilities of JCC. JCC is also authorized to
consider sales of Trust shares as a factor in selecting broker-dealers to
execute Fund portfolio transactions. In placing portfolio business with such
broker-dealers, JCC shall seek the best execution of each transaction. Subject
to the terms of this Agreement and the applicable requirements and provisions of
the law, including the Investment Company Act of 1940 and the Securities
Exchange Act of 1934, as amended, and in the event that JCC or an affiliate is
registered as a broker-dealer, JCC may select a broker or dealer with which it
or the Fund is affiliated. JCC or such affiliated broker-dealer may effect or
execute Fund portfolio transactions, whether on a securities exchange or in the
over-the-counter market, and receive separate compensation from the Fund
therefor. Notwithstanding the foregoing, the Trust shall retain the right to
direct the placement of all portfolio transactions, and the Trustees of the
Trust may establish policies or guidelines to be followed by JCC in placing
portfolio transactions for the Trust pursuant to the foregoing provisions. JCC
shall report on the placement of portfolio transactions in the prior fiscal
quarter at each quarterly meeting of such Trustees.

     9.   Termination. This Agreement may be terminated at any time, without
penalty, by the Board of Trustees of the Trust, or by the shareholders of the
Trust acting by vote of at least a majority of its outstanding voting
securities, provided in either case that sixty (60) days advance written notice
of termination be given to JCC at its principal place of business. This
Agreement may be terminated by JCC at any time, without penalty, by giving sixty
(60) days advance written notice of termination to the Trust, addressed to its
principal place of business. The Trust agrees that, consistent with the terms of
the Trust's Declaration of Trust, the Trust shall cease to use the name "Janus"
in connection with the Fund as soon as reasonably practicable following any
termination of this Agreement if JCC does not continue to provide investment
advice to the Fund after such termination.

     10.  Assignment. This Agreement shall terminate automatically in the
event of any assignment of this Agreement.


                                     - 4 -

<PAGE>


     11.  Term. This Agreement shall continue in effect until July 1, 1998,
unless sooner terminated in accordance with its terms, and shall continue in
effect from year to year thereafter only so long as such continuance is
specifically approved at least annually by the vote of a majority of the
Trustees of the Trust who are not parties hereto or interested persons of any
such party, cast in person at a meeting called for the purpose of voting on the
approval of the terms of such renewal, and by either the Board of Trustees of
the Trust or the affirmative vote of a majority of the outstanding voting
securities of the Trust. The annual approvals provided for herein shall be
effective to continue this Agreement from year to year if given within a period
beginning not more than sixty (60) days prior to July 1 of each applicable year,
notwithstanding the fact that more than three hundred sixty-five (365) days may
have elapsed since the date on which such approval was last given.

     12.  Amendments. This Agreement may be amended by the parties only if
such amendment is specifically approved (i) by a majority of the Trustees,
including a majority of the Trustees who are not interested persons (as that
phrase is defined in Section 2(a)(19) of the 1940 Act) of JCC and, if required
by applicable law, (ii) by the affirmative vote of a majority of the outstanding
voting securities of the Fund (as that phrase is defined in Section 2(a)(42) of
the 1940 Act).

     13.  Other Series. The Trustees shall determine the basis for making an
appropriate allocation of the Trust's expenses (other than those directly
attributable to the Fund) between the Fund and the other series of the Trust.

     14.  Limitation of Personal Liability. All the parties hereto
acknowledge and agree that all liabilities of the Trust arising, directly or
indirectly, under this Agreement, of any and every nature whatsoever, shall be
satisfied solely out of the assets of the Fund and that no Trustee, officer or
holder of shares of beneficial interest of the Trust shall be personally liable
for any of the foregoing liabilities. The Trust's Declaration of Trust, as
amended from time to time, is on file in the Office of the Secretary of State of
the Commonwealth of Massachusetts. Such Declaration of Trust describes in detail
the respective responsibilities and limitations on liability of the Trustees,
officers and holders of shares of beneficial interest of the Trust.

     15.  Limitation of Liability of JCC. JCC shall not be liable for any
error of judgment or mistake of law or for any loss arising out of any
investment or for any act or omission taken with respect to the Trust, except
for willful misfeasance, bad faith or gross negligence in the performance of its
duties, or by reason of reckless disregard of its obligations and duties
hereunder and except to the extent otherwise provided by law. As used in this
Section 15, "JCC" shall include any affiliate of JCC performing services for the
Trust contemplated hereunder and directors, officers and employees of JCC and
such affiliates.

     16.  Activities of JCC. The services of JCC to the Trust hereunder are
not to be deemed to be exclusive, and JCC and its affiliates are free to render
services to other parties. It is understood that trustees, officers and
shareholders of the Trust are or may become interested in JCC as directors,


                                     - 5 -

<PAGE>


officers and shareholders of JCC, that directors, officers, employees and
shareholders of JCC are or may become similarly interested in the Trust, and
that JCC may become interested in the Trust as a shareholder or otherwise.

     17.  Certain Definitions. The terms "vote of a majority of the
outstanding voting securities", "assignment" and "interested persons" when used
herein, shall have the respective meanings specified in the 1940 Act, as now in
effect or hereafter amended, and the rules and regulations thereunder, subject
to such orders, exemptions and interpretations as may be issued by the
Securities and Exchange Commission under said Act and as may be then in effect.

     IN WITNESS WHEREOF, the parties have caused their duly authorized
officers to execute this Investment Advisory Agreement as of this 1st day of
July, 1997.


                                   JANUS CAPITAL CORPORATION



                                   By: /s/ Steven R. Goodbarn
                                       Steven R. Goodbarn, Vice President


                                   JANUS INVESTMENT FUND



                                   By: /s/ Thomas H. Bailey
                                       Thomas H. Bailey, President


                                     - 6 -




                                                            EXHIBIT 5(f)

                              JANUS INVESTMENT FUND

                         INVESTMENT ADVISORY AGREEMENT

                         JANUS FEDERAL TAX-EXEMPT FUND


     THIS INVESTMENT ADVISORY AGREEMENT (the "Agreement") is made this 1st
day of July, 1997, between JANUS INVESTMENT FUND, a Massachusetts business trust
(the "Trust"), and JANUS CAPITAL CORPORATION, a Colorado corporation ("JCC").

                              W I T N E S S E T H:

     WHEREAS, the Trust is registered as an open-end management investment
company under the Investment Company Act of 1940, as amended (the "1940 Act"),
and has registered its shares for public offering under the Securities Act of
1933, as amended (the "1933 Act"); and

     WHEREAS, the Trust is authorized to create separate funds, each with
its own separate investment portfolio of which the beneficial interests are
represented by a separate series of shares; one of such funds created by the
Trust being designated as the Janus Federal Tax-Exempt Fund (the "Fund"); and

     WHEREAS, the Trust and JCC deem it mutually advantageous that JCC
should assist the Trustees and officers of the Trust in the management of the
securities portfolio of the Fund.

     NOW, THEREFORE, the parties agree as follows:

     1.   Investment Advisory Services. JCC shall furnish continuous advice
and recommendations to the Fund as to the acquisition, holding, or disposition
of any or all of the securities or other assets which the Fund may own or
contemplate acquiring from time to time. JCC shall give due consideration to the
investment policies and restrictions and the other statements concerning the
Fund in the Trust's declaration of trust, bylaws, and registration statements
under the 1940 Act and the 1933 Act, and to the provisions of the Internal
Revenue Code, as amended from time to time, applicable to the Fund as a
regulated investment company. In addition, JCC shall cause its officers to
attend meetings and furnish oral or written reports, as the Trust may reasonably
require, in order to keep the Trustees and appropriate officers of the Trust
fully informed as to the condition of the investment portfolio of the Fund, the
investment recommendations of JCC, and the investment considerations which have
given rise to those recommendations. JCC shall supervise the purchase and sale
of securities as directed by the appropriate officers of the Trust.

     2.   Other Services. JCC is hereby authorized (to the extent the Trust
has not otherwise contracted) but not obligated (to the extent it so notifies
the Trustees at least 60 days in advance), to perform (or arrange for the
performance by affiliates of) the management and administrative 

                                     - 1 -

<PAGE>


services necessary for the operation of the Fund. JCC is specifically
authorized, on behalf of the Trust, to conduct relations with custodians, 
depositories, transfer and pricing agents, accountants, attorneys,
underwriters, brokers and dealers, corporate fiduciaries, insurers, banks and 
such other persons in any such other capacity deemed by JCC to be necessary or
desirable. JCC shall generally monitor and report to Fund officers the Fund's 
compliance with investment policies and restrictions as set forth in the
currently effective prospectus and statement of additional information relating 
to the shares of the Fund under the Securities Act of 1933, as amended. JCC
shall make reports to the Trustees of its performance of services hereunder
upon request therefor and furnish advice and recommendations with respect to 
such other aspects of the business and affairs of the Fund as it shall
determine to be desirable. JCC is also authorized, subject to review by the 
Trustees, to furnish such other services as JCC shall from time to time 
determine to be necessary or useful to perform the services
contemplated by this Agreement.

     3.   Obligations of Trust. The Trust shall have the following obligations
under this Agreement:

          (a)  to keep JCC continuously and fully informed as to the
               composition of its investment portfolio and the
               nature of all of its assets and liabilities from time
               to time;

          (b)  to furnish JCC with a certified copy of any financial
               statement or report prepared for it by certified or
               independent public accountants and with copies of any
               financial statements or reports made to its
               shareholders or to any governmental body or
               securities exchange;

          (c)  to furnish JCC with any further materials or
               information which JCC may reasonably request to
               enable it to perform its function under this
               Agreement; and

          (d)  to compensate JCC for its services and reimburse JCC
               for its expenses incurred hereunder in accordance
                           with the provisions hereof.

     4.   Compensation. The Trust shall pay to JCC for its investment advisory
services a fee, calculated and payable for each day that this Agreement is in
effect, of 1/365 of 0.60% of the first $300,000,000 of the daily closing net
asset value of the Fund, plus 1/365 of 0.55% of the daily closing net asset
value in excess of $300,000,000. The fee shall be paid monthly.

     5.   Expenses Borne by JCC. In addition to the expenses which JCC may
incur in the performance of its investment advisory functions under this
Agreement, and the expenses which it may expressly undertake to incur and pay
under other agreements with the Trust or otherwise, JCC shall incur and pay the
following expenses relating to the Fund's operations without reimbursement from
the Fund:


                                     - 2 -

<PAGE>


          (a)  Reasonable compensation, fees and related expenses of
               the Trust's officers and its Trustees, except for
               such Trustees who are not interested persons of JCC;

          (b)  Rental of offices of the Trust; and

          (c)  All expenses of promoting the sale of shares of the Fund, other
               than expenses incurred in complying with federal and state laws
               and the law of any foreign country or territory or other
               jurisdiction applicable to the issue, offer or sale of shares
               of the Fund including without limitation registration fees and
               costs, the costs of preparing the Fund's registration statement
               and amendments thereto, and the costs and expenses of preparing,
               printing, and mailing prospectuses (and statements of additional
               information) to persons other than shareholders of the Fund.

     6.   Expenses Borne by the Trust. The Trust assumes and shall pay all
expenses incidental to its organization, operations and business not
specifically assumed or agreed to be paid by JCC pursuant to Sections 2 and 5
hereof, including, but not limited to, investment adviser fees; any
compensation, fees, or reimbursements which the Trust pays to its Trustees who
are not interested persons of JCC; compensation of the Fund's custodian,
transfer agent, registrar and dividend disbursing agent; legal, accounting,
audit and printing expenses; administrative, clerical, recordkeeping and
bookkeeping expenses; brokerage commissions and all other expenses in connection
with execution of portfolio transactions (including any appropriate commissions
paid to JCC or its affiliates for effecting exchange listed, over-the-counter or
other securities transactions); interest; all federal, state and local taxes
(including stamp, excise, income and franchise taxes); costs of stock
certificates and expenses of delivering such certificates to the purchaser
thereof; expenses of local representation in Massachusetts; expenses of
shareholders' meetings and of preparing, printing and distributing proxy
statements, notices, and reports to shareholders; expenses of preparing and
filing reports and tax returns with federal and state regulatory authorities;
all expenses incurred in complying with all federal and state laws and the laws
of any foreign country applicable to the issue, offer, or sale of shares of the
Fund, including, but not limited to, all costs involved in the registration or
qualification of shares of the Fund for sale in any jurisdiction, the costs of
portfolio pricing services and systems for compliance with blue sky laws, and
all costs involved in preparing, printing and mailing prospectuses and
statements of additional information of the Fund; and all fees, dues and other
expenses incurred by the Trust in connection with the membership of the Trust in
any trade association or other investment company organization. To the extent
that JCC shall perform any of the above described administrative and clerical
functions, including transfer agency, registry, dividend disbursing,
recordkeeping, bookkeeping, accounting and blue sky monitoring and registration
functions, and the preparation of reports and returns, the Trust shall pay to
JCC compensation for, or reimburse JCC for its expenses incurred in connection
with, such services as JCC and the Trust shall agree from time to time, any
other provision of this Agreement notwithstanding.


                                     - 3 -

<PAGE>


     7.   Treatment of Investment Advice. The Trust shall treat the investment
advice and recommendations of JCC as being advisory only, and shall retain full
control over its own investment policies. However, the Trustees may delegate to
the appropriate officers of the Trust, or to a committee of the Trustees, the
power to authorize purchases, sales or other actions affecting the portfolio of
the Fund in the interim between meetings of the Trustees.

     8.   Brokerage Commissions. For purposes of this Agreement, brokerage
commissions paid by the Fund upon the purchase or sale of its portfolio
securities shall be considered a cost of securities of the Fund and shall be
paid by the Fund. JCC is authorized and directed to place Fund portfolio
transactions only with brokers and dealers who render satisfactory service in
the execution of orders at the most favorable prices and at reasonable
commission rates, provided, however, that JCC may pay a broker or dealer an
amount of commission for effecting a securities transaction in excess of the
amount of commission another broker or dealer would have charged for effecting
that transaction if JCC determines in good faith that such amount of commission
was reasonable in relation to the value of the brokerage and research services
provided by such broker or dealer viewed in terms of either that particular
transaction or the overall responsibilities of JCC. JCC is also authorized to
consider sales of Trust shares as a factor in selecting broker-dealers to
execute Fund portfolio transactions. In placing portfolio business with such
broker-dealers, JCC shall seek the best execution of each transaction. Subject
to the terms of this Agreement and the applicable requirements and provisions of
the law, including the 1940 Act and the Securities Exchange Act of 1934, as
amended, and in the event that JCC or an affiliate is registered as a
broker-dealer, JCC may select a broker or dealer with which it or the Fund is
affiliated. JCC or such affiliated broker-dealer may effect or execute Fund
portfolio transactions, whether on a securities exchange or in the
over-the-counter market, and receive separate compensation from the Fund
therefor. Notwithstanding the foregoing, the Trust shall retain the right to
direct the placement of all portfolio transactions, and the Trustees of the
Trust may establish policies or guidelines to be followed by JCC in placing
portfolio transactions for the Trust pursuant to the foregoing provisions. JCC
shall report on the placement of portfolio transactions in the prior fiscal
quarter at each quarterly meeting of such Trustees.

     9.   Termination. This Agreement may be terminated at any time, without
penalty, by the Trustees of the Trust, or by the shareholders of the Trust
acting by vote of at least a majority of its outstanding voting securities,
provided in either case that sixty (60) days advance written notice of
termination be given to JCC at its principal place of business. This Agreement
may be terminated by JCC at any time, without penalty, by giving sixty (60) days
advance written notice of termination to the Trust, addressed to its principal
place of business. The Trust agrees that, consistent with the terms of the
Trust's Declaration of Trust, the Trust shall cease to use the name "Janus" in
connection with the Fund as soon as reasonably practicable following any
termination of this Agreement if JCC does not continue to provide investment
advice to the Fund after such termination.

     10.  Assignment. This Agreement shall terminate automatically in the
event of any assignment of this Agreement.



                                     - 4 -

<PAGE>


     11.  Term. This Agreement shall continue in effect until July 1, 1998,
unless sooner terminated in accordance with its terms, and shall continue in
effect from year to year thereafter only so long as such continuance is
specifically approved at least annually by the vote of a majority of the
Trustees of the Trust who are not parties hereto or interested persons of any
such party, cast in person at a meeting called for the purpose of voting on the
approval of the terms of such renewal, and by either the Trustees of the Trust
or the affirmative vote of a majority of the outstanding voting securities of
the Trust. The annual approvals provided for herein shall be effective to
continue this Agreement from year to year if given within a period beginning not
more than ninety (90) days prior to July 1 of each applicable year,
notwithstanding the fact that more than three hundred sixty-five (365) days may
have elapsed since the date on which such approval was last given.

     12.  Amendments. This Agreement may be amended by the parties only if
such amendment is specifically approved (i) by a majority of the Trustees,
including a majority of the Trustees who are not interested persons (as that
phrase is defined in Section 2(a)(19) of the 1940 Act) of JCC and, if required
by applicable law, (ii) by the affirmative vote of a majority of the outstanding
voting securities of the Fund (as that phrase is defined in Section 2(a)(42) of
the 1940 Act).

     13.  Other Series. The Trustees shall determine the basis for making an
appropriate allocation of the Trust's expenses (other than those directly
attributable to the Fund) between the Fund and the other series of the Trust.

     14.  Limitation of Personal Liability. All the parties hereto
acknowledge and agree that all liabilities of the Trust arising, directly or
indirectly, under this Agreement, of any and every nature whatsoever, shall be
satisfied solely out of the assets of the Fund and that no Trustee, officer or
holder of shares of beneficial interest of the Trust shall be personally liable
for any of the foregoing liabilities. The Trust's Declaration of Trust, as
amended from time to time, is on file in the Office of the Secretary of State of
the Commonwealth of Massachusetts. Such Declaration of Trust describes in detail
the respective responsibilities and limitations on liability of the Trustees,
officers and holders of shares of beneficial interest of the Trust.

     15.  Limitation of Liability of JCC. JCC shall not be liable for any
error of judgment or mistake of law or for any loss arising out of any
investment or for any act or omission taken with respect to the Trust, except
for willful misfeasance, bad faith or gross negligence in the performance of its
duties, or by reason of reckless disregard of its obligations and duties
hereunder and except to the extent otherwise provided by law. As used in this
Section 15, "JCC" shall include any affiliate of JCC performing services for the
Trust contemplated hereunder and directors, officers and employees of JCC and
such affiliates.


                                     - 5 -

<PAGE>


     16.  Activities of JCC. The services of JCC to the Trust hereunder are
not to be deemed to be exclusive, and JCC and its affiliates are free to render
services to other parties. It is understood that trustees, officers and
shareholders of the Trust are or may become interested in JCC as directors,
officers and shareholders of JCC, that directors, officers, employees and
shareholders of JCC are or may become similarly interested in the Trust, and
that JCC may become interested in the Trust as a shareholder or otherwise.

     17.  Certain Definitions. The terms "vote of a majority of the
outstanding voting securities", "assignment" and "interested persons" when used
herein, shall have the respective meanings specified in the 1940 Act, as now in
effect or hereafter amended, and the rules and regulations thereunder, subject
to such orders, exemptions and interpretations as may be issued by the
Securities and Exchange Commission under said Act and as may be then in effect.

     IN WITNESS WHEREOF, the parties have caused their duly authorized
officers to execute this Investment Advisory Agreement as of this 1st day of
July, 1997.


                                        JANUS CAPITAL CORPORATION



                                        By: /s/ Steven R. Goodbarn
                                            Steven R. Goodbarn, Vice President


                                        JANUS INVESTMENT FUND



                                        By: /s/ Thomas H. Bailey
                                            Thomas H. Bailey, President


                                     - 6 -

<PAGE>




                             JANUS INVESTMENT FUND

                         INVESTMENT ADVISORY AGREEMENT

                               JANUS MERCURY FUND


     THIS INVESTMENT ADVISORY AGREEMENT (the "Agreement") is made this 1st
day of July, 1997, between JANUS INVESTMENT FUND, a Massachusetts business trust
(the "Trust"), and JANUS CAPITAL CORPORATION, a Colorado corporation ("JCC").

                              W I T N E S S E T H:

     WHEREAS, the Trust is registered as an open-end management investment
company under the Investment Company Act of 1940, as amended (the "1940 Act"),
and has registered its shares for public offering under the Securities Act of
1933, as amended (the "1933 Act"); and

     WHEREAS, the Trust is authorized to create separate funds, each with
its own separate investment portfolio of which the beneficial interests are
represented by a separate series of shares; one of such funds created by the
Trust being designated as the Janus Mercury Fund (the "Fund"); and

     WHEREAS, the Trust and JCC deem it mutually advantageous that JCC
should assist the Trustees and officers of the Trust in the management of the
securities portfolio of the Fund.

     NOW, THEREFORE, the parties agree as follows:

     1.   Investment Advisory Services. JCC shall furnish continuous advice
and recommendations to the Fund as to the acquisition, holding, or disposition
of any or all of the securities or other assets which the Fund may own or
contemplate acquiring from time to time. JCC shall give due consideration to the
investment policies and restrictions and the other statements concerning the
Fund in the Trust's declaration of trust, bylaws, and registration statements
under the 1940 Act and the 1933 Act, and to the provisions of the Internal
Revenue Code, as amended from time to time, applicable to the Fund as a
regulated investment company. In addition, JCC shall cause its officers to
attend meetings and furnish oral or written reports, as the Trust may reasonably
require, in order to keep the Trustees and appropriate officers of the Trust
fully informed as to the condition of the investment portfolio of the Fund, the
investment recommendations of JCC, and the investment considerations which have
given rise to those recommendations. JCC shall supervise the purchase and sale
of securities as directed by the appropriate officers of the Trust.

     2.   Other Services. JCC is hereby authorized (to the extent the Trust
has not otherwise contracted) but not obligated (to the extent it so notifies
the Trustees at least 60 days in advance), to perform (or arrange for the
performance by affiliates of) the management and administrative services
necessary for the operation of the Fund. JCC is specifically authorized, on
behalf of the


                                     - 1 -

<PAGE>


Trust, to conduct relations with custodians, depositories, transfer and pricing
agents, accountants, attorneys, underwriters, brokers and dealers, corporate
fiduciaries, insurers, banks and such other persons in any such other capacity
deemed by JCC to be necessary or desirable. JCC shall generally monitor and
report to Fund officers the Fund's compliance with investment policies and
restrictions as set forth in the currently effective prospectus and statement of
additional information relating to the shares of the Fund under the Securities
Act of 1933, as amended. JCC shall make reports to the Trustees of its
performance of services hereunder upon request therefor and furnish advice and
recommendations with respect to such other aspects of the business and affairs
of the Fund as it shall determine to be desirable. JCC is also authorized,
subject to review by the Trustees, to furnish such other services as JCC shall
from time to time determine to be necessary or useful to perform the services
contemplated by this Agreement.

     3.   Obligations of Trust. The Trust shall have the following obligations
under this Agreement:

          (a)  to keep JCC continuously and fully informed as to the
               composition of its investment portfolio and the
               nature of all of its assets and liabilities from time
               to time;

          (b)  to furnish JCC with a certified copy of any financial
               statement or report prepared for it by certified or
               independent public accountants and with copies of any
               financial statements or reports made to its
               shareholders or to any governmental body or
               securities exchange;

          (c)  to furnish JCC with any further materials or
               information which JCC may reasonably request to
               enable it to perform its function under this
               Agreement; and

          (d)  to compensate JCC for its services and reimburse JCC
               for its expenses incurred hereunder in accordance
               with the provisions hereof.

     4.   Compensation. The Trust shall pay to JCC for its investment advisory
services a fee, calculated and payable for each day that this Agreement is in
effect, of 1/365 of 0.75% of the first $300,000,000 of the daily closing net
asset value of the Fund, plus 1/365 of 0.70% of the next $200,000,000 of the
daily closing net asset value of the Fund, plus 1/365 of 0.65% of the daily
closing net asset value of the Fund in excess of $500,000,000. The fee shall be
paid monthly.

     5.   Expenses Borne by JCC. In addition to the expenses which JCC may
incur in the performance of its investment advisory functions under this
Agreement, and the expenses which it may expressly undertake to incur and pay
under other agreements with the Trust or otherwise, JCC shall incur and pay the
following expenses relating to the Fund's operations without reimbursement from
the Fund:


                                     - 2 -

<PAGE>


          (a)  Reasonable compensation, fees and related expenses of
               the Trust's officers and its Trustees, except for
               such Trustees who are not interested persons of JCC;

          (b)  Rental of offices of the Trust; and

          (c)  All expenses of promoting the sale of shares of the Fund, other 
               than expenses incurred in complying with federal and state laws
               and the law of any foreign country or territory or other
               jurisdiction applicable to the issue, offer or sale of shares 
               of the Fund including without limitation registration fees and 
               costs, the costs of preparing the Fund's registration statement
               and amendments thereto, and the costs and expenses of preparing,
               printing, and mailing prospectuses (and statements of additional
               information) to persons other than shareholders of the Fund.

     6.   Expenses Borne by the Trust. The Trust assumes and shall pay all
expenses incidental to its organization, operations and business not
specifically assumed or agreed to be paid by JCC pursuant to Sections 2 and 5
hereof, including, but not limited to, investment adviser fees; any
compensation, fees, or reimbursements which the Trust pays to its Trustees who
are not interested persons of JCC; compensation of the Fund's custodian,
transfer agent, registrar and dividend disbursing agent; legal, accounting,
audit and printing expenses; administrative, clerical, recordkeeping and
bookkeeping expenses; brokerage commissions and all other expenses in connection
with execution of portfolio transactions (including any appropriate commissions
paid to JCC or its affiliates for effecting exchange listed, over-the-counter or
other securities transactions); interest; all federal, state and local taxes
(including stamp, excise, income and franchise taxes); costs of stock
certificates and expenses of delivering such certificates to the purchaser
thereof; expenses of local representation in Massachusetts; expenses of
shareholders' meetings and of preparing, printing and distributing proxy
statements, notices, and reports to shareholders; expenses of preparing and
filing reports and tax returns with federal and state regulatory authorities;
all expenses incurred in complying with all federal and state laws and the laws
of any foreign country applicable to the issue, offer, or sale of shares of the
Fund, including, but not limited to, all costs involved in the registration or
qualification of shares of the Fund for sale in any jurisdiction, the costs of
portfolio pricing services and systems for compliance with blue sky laws, and
all costs involved in preparing, printing and mailing prospectuses and
statements of additional information of the Fund; and all fees, dues and other
expenses incurred by the Trust in connection with the membership of the Trust in
any trade association or other investment company organization. To the extent
that JCC shall perform any of the above described administrative and clerical
functions, including transfer agency, registry, dividend disbursing,
recordkeeping, bookkeeping, accounting and blue sky monitoring and registration
functions, and the preparation of reports and returns, the Trust shall pay to
JCC compensation for, or reimburse JCC for its expenses incurred in connection
with, such services as JCC and the Trust shall agree from time to time, any
other provision of this Agreement notwithstanding.



                                     - 3 -

<PAGE>


     7.   Treatment of Investment Advice. The Trust shall treat the investment
advice and recommendations of JCC as being advisory only, and shall retain full
control over its own investment policies. However, the Trustees may delegate to
the appropriate officers of the Trust, or to a committee of the Trustees, the
power to authorize purchases, sales or other actions affecting the portfolio of
the Fund in the interim between meetings of the Trustees.

     8.   Brokerage Commissions. For purposes of this Agreement, brokerage
commissions paid by the Fund upon the purchase or sale of its portfolio
securities shall be considered a cost of securities of the Fund and shall be
paid by the Fund. JCC is authorized and directed to place Fund portfolio
transactions only with brokers and dealers who render satisfactory service in
the execution of orders at the most favorable prices and at reasonable
commission rates, provided, however, that JCC may pay a broker or dealer an
amount of commission for effecting a securities transaction in excess of the
amount of commission another broker or dealer would have charged for effecting
that transaction if JCC determines in good faith that such amount of commission
was reasonable in relation to the value of the brokerage and research services
provided by such broker or dealer viewed in terms of either that particular
transaction or the overall responsibilities of JCC. JCC is also authorized to
consider sales of Trust shares as a factor in selecting broker-dealers to
execute Fund portfolio transactions. In placing portfolio business with such
broker-dealers, JCC shall seek the best execution of each transaction. Subject
to the terms of this Agreement and the applicable requirements and provisions of
the law, including the 1940 Act and the Securities Exchange Act of 1934, as
amended, and in the event that JCC or an affiliate is registered as a
broker-dealer, JCC may select a broker or dealer with which it or the Fund is
affiliated. JCC or such affiliated broker-dealer may effect or execute Fund
portfolio transactions, whether on a securities exchange or in the
over-the-counter market, and receive separate compensation from the Fund
therefor. Notwithstanding the foregoing, the Trust shall retain the right to
direct the placement of all portfolio transactions, and the Trustees of the
Trust may establish policies or guidelines to be followed by JCC in placing
portfolio transactions for the Trust pursuant to the foregoing provisions. JCC
shall report on the placement of portfolio transactions in the prior fiscal
quarter at each quarterly meeting of such Trustees.

     9.   Termination. This Agreement may be terminated at any time, without
penalty, by the Trustees of the Trust, or by the shareholders of the Trust
acting by vote of at least a majority of its outstanding voting securities,
provided in either case that sixty (60) days advance written notice of
termination be given to JCC at its principal place of business. This Agreement
may be terminated by JCC at any time, without penalty, by giving sixty (60) days
advance written notice of termination to the Trust, addressed to its principal
place of business. The Trust agrees that, consistent with the terms of the
Trust's Declaration of Trust, the Trust shall cease to use the name "Janus" in
connection with the Fund as soon as reasonably practicable following any
termination of this Agreement if JCC does not continue to provide investment
advice to the Fund after such termination.

     10.  Assignment. This Agreement shall terminate automatically in the
event of any assignment of this Agreement.


                                     - 4 -

<PAGE>


     11.  Term. This Agreement shall continue in effect until July 1, 1998,
unless sooner terminated in accordance with its terms, and shall continue in
effect from year to year thereafter only so long as such continuance is
specifically approved at least annually by the vote of a majority of the
Trustees of the Trust who are not parties hereto or interested persons of any
such party, cast in person at a meeting called for the purpose of voting on the
approval of the terms of such renewal, and by either the Trustees of the Trust
or the affirmative vote of a majority of the outstanding voting securities of
the Trust. The annual approvals provided for herein shall be effective to
continue this Agreement from year to year if given within a period beginning not
more than ninety (90) days prior to July 1 of each applicable year,
notwithstanding the fact that more than three hundred sixty-five (365) days may
have elapsed since the date on which such approval was last given.

     12.  Amendments. This Agreement may be amended by the parties only if
such amendment is specifically approved (i) by a majority of the Trustees,
including a majority of the Trustees who are not interested persons (as that
phrase is defined in Section 2(a)(19) of the 1940 Act) of JCC and, if required
by applicable law, (ii) by the affirmative vote of a majority of the outstanding
voting securities of the Fund (as that phrase is defined in Section 2(a)(42) of
the 1940 Act).

     13.  Other Series. The Trustees shall determine the basis for making an
appropriate allocation of the Trust's expenses (other than those directly
attributable to the Fund) between the Fund and the other series of the Trust.

     14.  Limitation of Personal Liability. All the parties hereto
acknowledge and agree that all liabilities of the Trust arising, directly or
indirectly, under this Agreement, of any and every nature whatsoever, shall be
satisfied solely out of the assets of the Fund and that no Trustee, officer or
holder of shares of beneficial interest of the Trust shall be personally liable
for any of the foregoing liabilities. The Trust's Declaration of Trust, as
amended from time to time, is on file in the Office of the Secretary of State of
the Commonwealth of Massachusetts. Such Declaration of Trust describes in detail
the respective responsibilities and limitations on liability of the Trustees,
officers and holders of shares of beneficial interest of the Trust.

     15.  Limitation of Liability of JCC. JCC shall not be liable for any
error of judgment or mistake of law or for any loss arising out of any
investment or for any act or omission taken with respect to the Trust, except
for willful misfeasance, bad faith or gross negligence in the performance of its
duties, or by reason of reckless disregard of its obligations and duties
hereunder and except to the extent otherwise provided by law. As used in this
Section 15, "JCC" shall include any affiliate of JCC performing services for the
Trust contemplated hereunder and directors, officers and employees of JCC and
such affiliates.

     16.  Activities of JCC. The services of JCC to the Trust hereunder are
not to be deemed to be exclusive, and JCC and its affiliates are free to render
services to other parties. It is understood that trustees, officers and
shareholders of the Trust are or may become interested in JCC as directors,
officers and shareholders of JCC, that directors, officers, employees and
shareholders of JCC are or


                                     - 5 -

<PAGE>


may become similarly interested in the Trust, and that JCC may become interested
in the Trust as a shareholder or otherwise.

     17.  Certain Definitions. The terms "vote of a majority of the
outstanding voting securities", "assignment" and "interested persons" when used
herein, shall have the respective meanings specified in the 1940 Act, as now in
effect or hereafter amended, and the rules and regulations thereunder, subject
to such orders, exemptions and interpretations as may be issued by the
Securities and Exchange Commission under said Act and as may be then in effect.

     IN WITNESS WHEREOF, the parties have caused their duly authorized
officers to execute this Investment Advisory Agreement as of this 1st day of
July, 1997.


                                   JANUS CAPITAL CORPORATION



                                   By: /s/ Steven R. Goodbarn
                                       Steven R. Goodbarn, Vice President


                                   JANUS INVESTMENT FUND



                                   By: /s/ Thomas H. Bailey
                                       Thomas H. Bailey, President


                                     - 6 -


                                                            EXHIBIT 5(g)

                             JANUS INVESTMENT FUND

                          INVESTMENT ADVISORY AGREEMENT

                               JANUS OVERSEAS FUND


     THIS INVESTMENT ADVISORY AGREEMENT (the "Agreement") is made this 1st
day of July, 1997, between JANUS INVESTMENT FUND, a Massachusetts business trust
(the "Trust"), and JANUS CAPITAL CORPORATION, a Colorado corporation ("JCC").

                              W I T N E S S E T H:

     WHEREAS, the Trust is registered as an open-end management investment
company under the Investment Company Act of 1940, as amended (the "1940 Act"),
and has registered its shares for public offering under the Securities Act of
1933, as amended (the "1933 Act"); and

     WHEREAS, the Trust is authorized to create separate funds, each with
its own separate investment portfolio of which the beneficial interests are
represented by a separate series of shares; one of such funds created by the
Trust being designated as the Janus Overseas Fund (the "Fund"); and

     WHEREAS, the Trust and JCC deem it mutually advantageous that JCC
should assist the Trustees and officers of the Trust in the management of the
securities portfolio of the Fund.

     NOW, THEREFORE, the parties agree as follows:

     1.   Investment Advisory Services. JCC shall furnish continuous advice
and recommendations to the Fund as to the acquisition, holding, or disposition
of any or all of the securities or other assets which the Fund may own or
contemplate acquiring from time to time. JCC shall give due consideration to the
investment policies and restrictions and the other statements concerning the
Fund in the Trust's declaration of trust, bylaws, and registration statements
under the 1940 Act and the 1933 Act, and to the provisions of the Internal
Revenue Code, as amended from time to time, applicable to the Fund as a
regulated investment company. In addition, JCC shall cause its officers to
attend meetings and furnish oral or written reports, as the Trust may reasonably
require, in order to keep the Trustees and appropriate officers of the Trust
fully informed as to the condition of the investment portfolio of the Fund, the
investment recommendations of JCC, and the investment considerations which have
given rise to those recommendations. JCC shall supervise the purchase and sale
of securities as directed by the appropriate officers of the Trust.

     2.   Other Services. JCC is hereby authorized (to the extent the Trust
has not otherwise contracted) but not obligated (to the extent it so notifies
the Trustees at least 60 days in advance), to perform (or arrange for the
performance by affiliates of) the management and administrative 


                                     - 1 -

<PAGE>

services necessary for the operation of the Fund. JCC is specifically
authorized, on behalf of the Trust, to conduct relations with custodians, 
depositories, transfer and pricing agents, accountants, attorneys, underwriters,
brokers and dealers, corporate fiduciaries, insurers, banks and such other
persons in any such other capacity deemed by JCC to be necessary or desirable.
JCC shall generally monitor and report to Fund officers the Fund's compliance
with investment policies and restrictions as set forth in the currently 
effective prospectus and statement of additional information relating to the
shares of the Fund under the Securities Act of 1933, as amended. JCC shall make
reports to the Trustees of its performance of services hereunder upon request
therefor and furnish advice and recommendations with respect to such other
aspects of the business and affairs of the Fund as it shall determine to be 
desirable. JCC is also authorized,subject to review by the Trustees, to furnish
such other services as JCC shall from time to time determine to be necessary or
useful to perform the services contemplated by this Agreement.

     3.   Obligations of Trust. The Trust shall have the following obligations
under this Agreement:

          (a)  to keep JCC continuously and fully informed as to the
               composition of its investment portfolio and the
               nature of all of its assets and liabilities from time
               to time;

          (b)  to furnish JCC with a certified copy of any financial
               statement or report prepared for it by certified or
               independent public accountants and with copies of any
               financial statements or reports made to its
               shareholders or to any governmental body or
               securities exchange;

          (c)  to furnish JCC with any further materials or
               information which JCC may reasonably request to
               enable it to perform its function under this
               Agreement; and

          (d)  to compensate JCC for its services and reimburse JCC
               for its expenses incurred hereunder in accordance
               with the provisions hereof.

     4.   Compensation. The Trust shall pay to JCC for its investment advisory
services a fee, calculated and payable for each day that this Agreement is in
effect, of 1/365 of 0.75% of the first $300,000,000 of the daily closing net
asset value of the Fund, plus 1/365 of 0.70% of the next $200,000,000 of the
daily closing net asset value of the Fund, plus 1/365 of 0.65% of the daily
closing net asset value of the Fund in excess of $500,000,000. The fee shall be
paid monthly.

     5.   Expenses Borne by JCC. In addition to the expenses which JCC may
incur in the performance of its investment advisory functions under this
Agreement, and the expenses which it may expressly undertake to incur and pay
under other agreements with the Trust or otherwise, JCC shall incur and pay the
following expenses relating to the Fund's operations without reimbursement from
the Fund:


                                     - 2 -

<PAGE>


          (a)  Reasonable compensation, fees and related expenses of
               the Trust's officers and its Trustees, except for
               such Trustees who are not interested persons of JCC;

          (b)  Rental of offices of the Trust; and

          (c)  All expenses of promoting the sale of shares of the Fund, other
               than expenses incurred in complying with federal and state laws
               and the law of any foreign country or territory or other 
               jurisdiction applicable to the issue, offer or sale of shares of
               the Fund including without limitation registration fees and 
               costs, the costs of preparing the Fund's registration statement
               and amendments thereto, and the costs and expenses of preparing,
               printing, and mailing prospectuses (and statements of additional
               information) to persons other than shareholders of the Fund.

     6.   Expenses Borne by the Trust. The Trust assumes and shall pay all
expenses incidental to its organization, operations and business not
specifically assumed or agreed to be paid by JCC pursuant to Sections 2 and 5
hereof, including, but not limited to, investment adviser fees; any
compensation, fees, or reimbursements which the Trust pays to its Trustees who
are not interested persons of JCC; compensation of the Fund's custodian,
transfer agent, registrar and dividend disbursing agent; legal, accounting,
audit and printing expenses; administrative, clerical, recordkeeping and
bookkeeping expenses; brokerage commissions and all other expenses in connection
with execution of portfolio transactions (including any appropriate commissions
paid to JCC or its affiliates for effecting exchange listed, over-the-counter or
other securities transactions); interest; all federal, state and local taxes
(including stamp, excise, income and franchise taxes); costs of stock
certificates and expenses of delivering such certificates to the purchaser
thereof; expenses of local representation in Massachusetts; expenses of
shareholders' meetings and of preparing, printing and distributing proxy
statements, notices, and reports to shareholders; expenses of preparing and
filing reports and tax returns with federal and state regulatory authorities;
all expenses incurred in complying with all federal and state laws and the laws
of any foreign country applicable to the issue, offer, or sale of shares of the
Fund, including, but not limited to, all costs involved in the registration or
qualification of shares of the Fund for sale in any jurisdiction, the costs of
portfolio pricing services and systems for compliance with blue sky laws, and
all costs involved in preparing, printing and mailing prospectuses and
statements of additional information of the Fund; and all fees, dues and other
expenses incurred by the Trust in connection with the membership of the Trust in
any trade association or other investment company organization. To the extent
that JCC shall perform any of the above described administrative and clerical
functions, including transfer agency, registry, dividend disbursing,
recordkeeping, bookkeeping, accounting and blue sky monitoring and registration
functions, and the preparation of reports and returns, the Trust shall pay to
JCC compensation for, or reimburse JCC for its expenses incurred in connection
with, such services as JCC and the Trust shall agree from time to time, any
other provision of this Agreement notwithstanding.


                                     - 3 -

<PAGE>


     7.   Treatment of Investment Advice. The Trust shall treat the investment
advice and recommendations of JCC as being advisory only, and shall retain full
control over its own investment policies. However, the Trustees may delegate to
the appropriate officers of the Trust, or to a committee of the Trustees, the
power to authorize purchases, sales or other actions affecting the portfolio of
the Fund in the interim between meetings of the Trustees.

     8.   Brokerage Commissions. For purposes of this Agreement, brokerage
commissions paid by the Fund upon the purchase or sale of its portfolio
securities shall be considered a cost of securities of the Fund and shall be
paid by the Fund. JCC is authorized and directed to place Fund portfolio
transactions only with brokers and dealers who render satisfactory service in
the execution of orders at the most favorable prices and at reasonable
commission rates, provided, however, that JCC may pay a broker or dealer an
amount of commission for effecting a securities transaction in excess of the
amount of commission another broker or dealer would have charged for effecting
that transaction if JCC determines in good faith that such amount of commission
was reasonable in relation to the value of the brokerage and research services
provided by such broker or dealer viewed in terms of either that particular
transaction or the overall responsibilities of JCC. JCC is also authorized to
consider sales of Trust shares as a factor in selecting broker-dealers to
execute Fund portfolio transactions. In placing portfolio business with such
broker-dealers, JCC shall seek the best execution of each transaction. Subject
to the terms of this Agreement and the applicable requirements and provisions of
the law, including the 1940 Act and the Securities Exchange Act of 1934, as
amended, and in the event that JCC or an affiliate is registered as a
broker-dealer, JCC may select a broker or dealer with which it or the Fund is
affiliated. JCC or such affiliated broker-dealer may effect or execute Fund
portfolio transactions, whether on a securities exchange or in the
over-the-counter market, and receive separate compensation from the Fund
therefor. Notwithstanding the foregoing, the Trust shall retain the right to
direct the placement of all portfolio transactions, and the Trustees of the
Trust may establish policies or guidelines to be followed by JCC in placing
portfolio transactions for the Trust pursuant to the foregoing provisions. JCC
shall report on the placement of portfolio transactions in the prior fiscal
quarter at each quarterly meeting of such Trustees.

     9.   Termination. This Agreement may be terminated at any time, without
penalty, by the Trustees of the Trust, or by the shareholders of the Trust
acting by vote of at least a majority of its outstanding voting securities,
provided in either case that sixty (60) days advance written notice of
termination be given to JCC at its principal place of business. This Agreement
may be terminated by JCC at any time, without penalty, by giving sixty (60) days
advance written notice of termination to the Trust, addressed to its principal
place of business. The Trust agrees that, consistent with the terms of the
Trust's Declaration of Trust, the Trust shall cease to use the name "Janus" in
connection with the Fund as soon as reasonably practicable following any
termination of this Agreement if JCC does not continue to provide investment
advice to the Fund after such termination.

     10.  Assignment. This Agreement shall terminate automatically in the
event of any assignment of this Agreement.



                                     - 4 -

<PAGE>


     11.  Term. This Agreement shall continue in effect until July 1, 1998,
unless sooner terminated in accordance with its terms, and shall continue in
effect from year to year thereafter only so long as such continuance is
specifically approved at least annually by the vote of a majority of the
Trustees of the Trust who are not parties hereto or interested persons of any
such party, cast in person at a meeting called for the purpose of voting on the
approval of the terms of such renewal, and by either the Trustees of the Trust
or the affirmative vote of a majority of the outstanding voting securities of
the Trust. The annual approvals provided for herein shall be effective to
continue this Agreement from year to year if given within a period beginning not
more than ninety (90) days prior to July 1 of each applicable year,
notwithstanding the fact that more than three hundred sixty-five (365) days may
have elapsed since the date on which such approval was last given.

     12.  Amendments. This Agreement may be amended by the parties only if
such amendment is specifically approved (i) by a majority of the Trustees,
including a majority of the Trustees who are not interested persons (as that
phrase is defined in Section 2(a)(19) of the 1940 Act) of JCC and, if required
by applicable law, (ii) by the affirmative vote of a majority of the outstanding
voting securities of the Fund (as that phrase is defined in Section 2(a)(42) of
the 1940 Act).

     13.  Other Series. The Trustees shall determine the basis for making an
appropriate allocation of the Trust's expenses (other than those directly
attributable to the Fund) between the Fund and the other series of the Trust.

     14.  Limitation of Personal Liability. All the parties hereto
acknowledge and agree that all liabilities of the Trust arising, directly or
indirectly, under this Agreement, of any and every nature whatsoever, shall be
satisfied solely out of the assets of the Fund and that no Trustee, officer or
holder of shares of beneficial interest of the Trust shall be personally liable
for any of the foregoing liabilities. The Trust's Declaration of Trust, as
amended from time to time, is on file in the Office of the Secretary of State of
the Commonwealth of Massachusetts. Such Declaration of Trust describes in detail
the respective responsibilities and limitations on liability of the Trustees,
officers and holders of shares of beneficial interest of the Trust.

     15.  Limitation of Liability of JCC. JCC shall not be liable for any
error of judgment or mistake of law or for any loss arising out of any
investment or for any act or omission taken with respect to the Trust, except
for willful misfeasance, bad faith or gross negligence in the performance of its
duties, or by reason of reckless disregard of its obligations and duties
hereunder and except to the extent otherwise provided by law. As used in this
Section 15, "JCC" shall include any affiliate of JCC performing services for the
Trust contemplated hereunder and directors, officers and employees of JCC and
such affiliates.

     16.  Activities of JCC. The services of JCC to the Trust hereunder are
not to be deemed to be exclusive, and JCC and its affiliates are free to render
services to other parties. It is understood that trustees, officers and
shareholders of the Trust are or may become interested in JCC as directors,
officers and shareholders of JCC, that directors, officers, employees and
shareholders of JCC are or


                                     - 5 -

<PAGE>


may become similarly interested in the Trust, and that JCC may become interested
in the Trust as a shareholder or otherwise.

     17.  Certain Definitions. The terms "vote of a majority of the
outstanding voting securities", "assignment" and "interested persons" when used
herein, shall have the respective meanings specified in the 1940 Act, as now in
effect or hereafter amended, and the rules and regulations thereunder, subject
to such orders, exemptions and interpretations as may be issued by the
Securities and Exchange Commission under said Act and as may be then in effect.

     IN WITNESS WHEREOF, the parties have caused their duly authorized
officers to execute this Investment Advisory Agreement as of this 1st day of
July, 1997.


                                        JANUS CAPITAL CORPORATION



                                        By: /s/ Steven R. Goodbarn
                                            Steven R. Goodbarn, Vice President


                                        JANUS INVESTMENT FUND



                                         By: /s/ Thomas H. Bailey
                                             Thomas H. Bailey, President


                                     - 6 -



                                                            EXHIBIT 5(h)


                             JANUS INVESTMENT FUND

                         INVESTMENT ADVISORY AGREEMENT

                            JANUS MONEY MARKET FUND


     THIS INVESTMENT ADVISORY AGREEMENT (the "Agreement") is made this 1st
day of July, 1997, between JANUS INVESTMENT FUND, a Massachusetts business trust
(the "Trust"), and JANUS CAPITAL CORPORATION, a Colorado corporation ("JCC").

                              W I T N E S S E T H:

     WHEREAS, the Trust is registered as an open-end management investment
company under the Investment Company Act of 1940, as amended (the "1940 Act"),
and has registered its shares for public offering under the Securities Act of
1933, as amended (the "1933 Act"); and

     WHEREAS, the Trust is authorized to create separate funds, each with
its own separate investment portfolio of which the beneficial interests are
represented by a separate series of shares of the Trust; one of such funds
created by the Trust being designated as the Janus Money Market Fund (the
"Fund"); and

     WHEREAS, the Trust and JCC have entered into a separate agreement for the
provision of administrative services; and

         WHEREAS, the Trust and JCC deem it mutually advantageous that JCC
should assist the Trustees and officers of the Trust in the management of the
securities portfolio of the Fund as described below.

         NOW, THEREFORE, the parties agree as follows:

         1. Investment Advisory Services. JCC shall furnish continuous advice
and recommendations to the Fund as to the acquisition, holding or disposition of
any or all of the securities or other assets which the Fund may own or
contemplate acquiring from time to time. JCC shall give due consideration to the
investment policies and restrictions and the other statements concerning the
Fund in the Trust's declaration of trust, bylaws, and registration statements
under the 1940 Act and the 1933 Act (as they may be supplemented from time to
time and as authorized by the Trustees), to policies and directives affecting
the Fund adopted by the Trustees, and to the provisions of the Internal Revenue
Code, as amended from time to time, applicable to the Fund as a regulated
investment company. In addition, JCC shall cause its officers to attend meetings
and furnish oral or written reports, as the Trust may reasonably require, in
order to keep the Trustees and appropriate officers of the Trust fully informed
as to the condition of the investment portfolio of the Fund, the investment
recommendations of JCC, and the investment considerations which have given


                                     - 1 -

<PAGE>



rise to those recommendations. JCC shall supervise the purchase and sale of
securities and other obligations and related brokerage and dealer relationships
as directed by the appropriate officers of the Trust.

     2.   Other Services. JCC is hereby authorized, subject to review by the
Trustees, to furnish or arrange for such other services as JCC shall from time
to time determine to be necessary or useful to perform the services specifically
contemplated by this Agreement.

     3.   Obligations of Trust. The Trust shall have the following obligations
under this Agreement:

               a.   to keep JCC continuously and fully informed as to the
                    composition of its investment portfolio and the nature of
                    all of its assets and liabilities from time to time;

               b.   to furnish JCC with a certified copy of any financial
                    statement or report prepared for it by certified or
                    independent public accountants and with copies of any
                    financial statements or reports made to its
                    shareholders or to any governmental body or
                    securities exchange;

               c.   to furnish JCC with any further materials or
                    information which JCC may reasonably request to
                    enable it to perform its functions under this
                    Agreement; and

               d.   to compensate JCC for its services and reimburse JCC
                    for its expenses incurred hereunder in accordance
                    with the provisions hereof.

     4.   Compensation. The Trust shall pay to JCC for its investment advisory
services a fee, payable in arrears on the last day of each month during which or
part of which this Agreement is in effect, at the rate of 1/365 of 0.20% of the
aggregate closing net asset value of the shares of the Fund for each day of such
month. For the month during which this Agreement becomes effective and the month
during which it terminates, however, there shall be an appropriate proration of
the fee payable for such month based on the number of calendar days of such
month during which this Agreement is effective.

     5.   Expenses Borne by the Trust. The Trust shall bear all expenses
incidental to the operation of the Fund.

     6.   Treatment of Investment Advice. The Trust shall treat the investment
advice and recommendations of JCC as being advisory only, and shall retain full
control over its own investment policies. However, the Trustees may delegate to
the appropriate officers of the Trust, or to a committee of the Trustees, the
power to authorize purchases, sales or other actions affecting the portfolio of
the Fund.


                                     - 2 -

<PAGE>


     7.   Termination. This Agreement may be terminated at any time, without
penalty, by the Trustees of the Trust, or by the shareholders of the Trust
acting by vote of at least a majority of its outstanding voting securities,
provided in either case that sixty (60) days advance written notice of
termination be given to JCC at its principal place of business. This Agreement
may be terminated by JCC at any time, without penalty, by giving sixty (60) days
advance written notice of termination to the Trust, addressed to its principal
place of business. The Trust agrees that, consistent with the terms of the
Trust's Declaration of Trust, the Trust shall cease to use the name "Janus" in
connection with the Fund as soon as reasonably practicable following any
termination of this Agreement if JCC does not continue to provide investment
advice to the Fund after such termination.

     8.   Assignment. This Agreement shall terminate automatically in the
event of any assignment of this Agreement.

     9.   Term. This Agreement shall continue in effect until July 1, 1998,
unless sooner terminated in accordance with its terms, and shall continue in
effect from year to year thereafter only so long as such continuance is
specifically approved at least annually by the vote of a majority of the
Trustees of the Trust, including a majority of those Trustees who are not
parties hereto or interested persons of any such party, cast in person at a
meeting called for the purpose of voting on the approval of the terms of such
renewal, or by the affirmative vote of a majority of the outstanding voting
securities of the Trust; provided, however, that if this Agreement or the
continuation of this Agreement is not approved by the Fund, JCC may continue to
render to the Fund the services described herein in the manner and to the extent
permitted by the 1940 Act and regulations thereunder. The annual approvals
provided for herein shall be effective to continue this Agreement in effect from
year to year if given within a period beginning not more than ninety (90) days
prior to July 1 of each applicable year, notwithstanding the fact that more than
three hundred sixty-five (365) days may have elapsed since the date on which
such approval was last given.

     10.  Amendments. This Agreement may be amended by the parties only if
such amendment is specifically approved (a) by a majority of the Trustees,
including a majority of the Trustees who are not interested persons of JCC and,
(b) if required by applicable law, by the affirmative vote of a majority of the
outstanding voting securities of the Fund.

     11.  Limitation of Personal Liability. All the parties hereto
acknowledge and agree that all liabilities of the Trust arising, directly or
indirectly, under this Agreement, of any and every nature whatsoever, shall be
satisfied solely out of the assets of the Fund and that no Trustee, officer or
holder of shares of beneficial interest of the Trust shall be personally liable
for any of the foregoing liabilities. The Trust's Declaration of Trust, as
amended from time to time, is on file in the Office of the Secretary of State of
the Commonwealth of Massachusetts. Such Declaration of Trust describes in detail
the respective responsibilities and limitations on liability of the Trustees,
officers and holders of shares of beneficial interest of the Trust.

     12.  Limitation of Liability of JCC. JCC shall not be liable for any
error of judgment or mistake of law, for any loss arising out of any investment,
or for any act or omission taken with


                                     - 3 -

<PAGE>


respect to the Trust, except for willful misfeasance, bad faith or gross
negligence in the performance of its duties, or by reason of reckless disregard
of its obligations and duties hereunder and except to the extent otherwise
provided by law. As used in this Section 12, "JCC" shall include any affiliate
of JCC performing services for the Trust contemplated hereunder and directors,
officers and employees of JCC and such affiliates.

     13.  Activities of JCC. The services of JCC to the Trust hereunder are
not to be deemed to be exclusive, and JCC and its affiliates are free to render
services to other parties. It is understood that trustees, officers and
shareholders of the Trust are or may become interested in JCC as directors,
officers and shareholders of JCC, that directors, officers, employees and
shareholders of JCC are or may become similarly interested in the Trust, and
that JCC may become interested in the Trust as a shareholder or otherwise.

     14.  Certain Definitions. The terms "vote of a majority of the
outstanding voting securities," "assignment" and "interested persons" when used
herein, shall have the respective meanings specified in the 1940 Act, as now in
effect or hereafter amended, and the rules and regulations thereunder, subject
to such orders, exemptions and interpretations as may be issued by the
Securities and Exchange Commission under said Act and as may be then in effect.

     IN WITNESS WHEREOF, the parties have caused their duly authorized
officers to execute this Investment Advisory Agreement as of the date and year
first above written.


                                        JANUS CAPITAL CORPORATION



                                        By: /s/ Steven R. Goodbarn
                                            Steven R. Goodbarn, Vice President


                                        JANUS INVESTMENT FUND



                                        By: /s/ Thomas H. Bailey
                                            Thomas H. Bailey, President


                                     - 4 -

<PAGE>



                             JANUS INVESTMENT FUND

                         INVESTMENT ADVISORY AGREEMENT

                       JANUS GOVERNMENT MONEY MARKET FUND


     THIS INVESTMENT ADVISORY AGREEMENT (the "Agreement") is made this 1st
day of July, 1997, between JANUS INVESTMENT FUND, a Massachusetts business trust
(the "Trust"), and JANUS CAPITAL CORPORATION, a Colorado corporation ("JCC").

                              W I T N E S S E T H:

     WHEREAS, the Trust is registered as an open-end management investment
company under the Investment Company Act of 1940, as amended (the "1940 Act"),
and has registered its shares for public offering under the Securities Act of
1933, as amended (the "1933 Act"); and

     WHEREAS, the Trust is authorized to create separate funds, each with
its own separate investment portfolio of which the beneficial interests are
represented by a separate series of shares of the Trust; one of such funds
created by the Trust being designated as the Janus Government Money Market Fund
(the "Fund"); and

     WHEREAS, the Trust and JCC have entered into a separate agreement for the
provision of administrative services; and

     WHEREAS, the Trust and JCC deem it mutually advantageous that JCC
should assist the Trustees and officers of the Trust in the management of the
securities portfolio of the Fund as described below.

     NOW, THEREFORE, the parties agree as follows:

     1. Investment Advisory Services. JCC shall furnish continuous advice
and recommendations to the Fund as to the acquisition, holding or disposition of
any or all of the securities or other assets which the Fund may own or
contemplate acquiring from time to time. JCC shall give due consideration to the
investment policies and restrictions and the other statements concerning the
Fund in the Trust's declaration of trust, bylaws, and registration statements
under the 1940 Act and the 1933 Act (as they may be supplemented from time to
time and as authorized by the Trustees), to policies and directives affecting
the Fund adopted by the Trustees, and to the provisions of the Internal Revenue
Code, as amended from time to time, applicable to the Fund as a regulated
investment company. In addition, JCC shall cause its officers to attend meetings
and furnish oral or written reports, as the Trust may reasonably require, in
order to keep the Trustees and appropriate officers of the Trust fully informed
as to the condition of the investment portfolio of the Fund, the investment
recommendations of JCC, and the investment considerations which have given


                                     - 1 -

<PAGE>


rise to those recommendations. JCC shall supervise the purchase and sale of
securities and other obligations and related brokerage and dealer relationships
as directed by the appropriate officers of the Trust.

     2.   Other Services. JCC is hereby authorized, subject to review by the
Trustees, to furnish or arrange for such other services as JCC shall from time
to time determine to be necessary or useful to perform the services specifically
contemplated by this Agreement.

     3.   Obligations of Trust. The Trust shall have the following obligations
under this Agreement:

          a.   to keep JCC continuously and fully informed as to the 
               composition of its investment portfolio and the nature of all of
               its assets and liabilities from time to time;

          b.   to furnish JCC with a certified copy of any financial
               statement or report prepared for it by certified or
               independent public accountants and with copies of any
               financial statements or reports made to its
               shareholders or to any governmental body or
               securities exchange;

          c.   to furnish JCC with any further materials or
               information which JCC may reasonably request to
               enable it to perform its functions under this
               Agreement; and

          d.   to compensate JCC for its services and reimburse JCC
               for its expenses incurred hereunder in accordance
               with the provisions hereof.

     4.   Compensation. The Trust shall pay to JCC for its investment advisory
services a fee, payable in arrears on the last day of each month during which or
part of which this Agreement is in effect, at the rate of 1/365 of 0.20% of the
aggregate closing net asset value of the shares of the Fund for each day of such
month. For the month during which this Agreement becomes effective and the month
during which it terminates, however, there shall be an appropriate proration of
the fee payable for such month based on the number of calendar days of such
month during which this Agreement is effective.

     5.   Expenses Borne by the Trust. The Trust shall bear all expenses
incidental to the operation of the Fund.

     6.   Treatment of Investment Advice. The Trust shall treat the investment
advice and recommendations of JCC as being advisory only, and shall retain full
control over its own investment policies. However, the Trustees may delegate to
the appropriate officers of the Trust, or to a committee of the Trustees, the
power to authorize purchases, sales or other actions affecting the portfolio of
the Fund.


                                     - 2 -

<PAGE>


     7.   Termination. This Agreement may be terminated at any time, without
penalty, by the Trustees of the Trust, or by the shareholders of the Trust
acting by vote of at least a majority of its outstanding voting securities,
provided in either case that sixty (60) days advance written notice of
termination be given to JCC at its principal place of business. This Agreement
may be terminated by JCC at any time, without penalty, by giving sixty (60) days
advance written notice of termination to the Trust, addressed to its principal
place of business. The Trust agrees that, consistent with the terms of the
Trust's Declaration of Trust, the Trust shall cease to use the name "Janus" in
connection with the Fund as soon as reasonably practicable following any
termination of this Agreement if JCC does not continue to provide investment
advice to the Fund after such termination.

     8.   Assignment. This Agreement shall terminate automatically in the
event of any assignment of this Agreement.

     9.   Term. This Agreement shall continue in effect until July 1, 1998,
unless sooner terminated in accordance with its terms, and shall continue in
effect from year to year thereafter only so long as such continuance is
specifically approved at least annually by the vote of a majority of the
Trustees of the Trust, including a majority of those Trustees who are not
parties hereto or interested persons of any such party, cast in person at a
meeting called for the purpose of voting on the approval of the terms of such
renewal, or by the affirmative vote of a majority of the outstanding voting
securities of the Trust; provided, however, that if this Agreement or the
continuation of this Agreement is not approved by the Fund, JCC may continue to
render to the Fund the services described herein in the manner and to the extent
permitted by the 1940 Act and regulations thereunder. The annual approvals
provided for herein shall be effective to continue this Agreement in effect from
year to year if given within a period beginning not more than ninety (90) days
prior to July 1 of each applicable year, notwithstanding the fact that more than
three hundred sixty-five (365) days may have elapsed since the date on which
such approval was last given.

     10.  Amendments. This Agreement may be amended by the parties only if
such amendment is specifically approved (a) by a majority of the Trustees,
including a majority of the Trustees who are not interested persons of JCC and,
(b) if required by applicable law, by the affirmative vote of a majority of the
outstanding voting securities of the Fund.

     11.  Limitation of Personal Liability. All the parties hereto
acknowledge and agree that all liabilities of the Trust arising, directly or
indirectly, under this Agreement, of any and every nature whatsoever, shall be
satisfied solely out of the assets of the Fund and that no Trustee, officer or
holder of shares of beneficial interest of the Trust shall be personally liable
for any of the foregoing liabilities. The Trust's Declaration of Trust, as
amended from time to time, is on file in the Office of the Secretary of State of
the Commonwealth of Massachusetts. Such Declaration of Trust describes in detail
the respective responsibilities and limitations on liability of the Trustees,
officers and holders of shares of beneficial interest of the Trust.

     12.  Limitation of Liability of JCC. JCC shall not be liable for any
error of judgment or mistake of law, for any loss arising out of any investment,
or for any act or omission taken with


                                     - 3 -

<PAGE>


respect to the Trust, except for willful misfeasance, bad faith or gross
negligence in the performance of its duties, or by reason of reckless disregard
of its obligations and duties hereunder and except to the extent otherwise
provided by law. As used in this Section 12, "JCC" shall include any affiliate
of JCC performing services for the Trust contemplated hereunder and directors,
officers and employees of JCC and such affiliates.

     13.  Activities of JCC. The services of JCC to the Trust hereunder are
not to be deemed to be exclusive, and JCC and its affiliates are free to render
services to other parties. It is understood that trustees, officers and
shareholders of the Trust are or may become interested in JCC as directors,
officers and shareholders of JCC, that directors, officers, employees and
shareholders of JCC are or may become similarly interested in the Trust, and
that JCC may become interested in the Trust as a shareholder or otherwise.

     14.  Certain Definitions. The terms "vote of a majority of the
outstanding voting securities," "assignment" and "interested persons" when used
herein, shall have the respective meanings specified in the 1940 Act, as now in
effect or hereafter amended, and the rules and regulations thereunder, subject
to such orders, exemptions and interpretations as may be issued by the
Securities and Exchange Commission under said Act and as may be then in effect.

     IN WITNESS WHEREOF, the parties have caused their duly authorized
officers to execute this Investment Advisory Agreement as of the date and year
first above written.


                                        JANUS CAPITAL CORPORATION



                                        By: /s/ Steven R. Goodbarn
                                            Steven R. Goodbarn, Vice President


                                        JANUS INVESTMENT FUND



                                        By: /s/ Thomas H. Bailey
                                            Thomas H. Bailey, President


                                     - 4 -

<PAGE>



                             JANUS INVESTMENT FUND

                         INVESTMENT ADVISORY AGREEMENT

                       JANUS TAX-EXEMPT MONEY MARKET FUND


     THIS INVESTMENT ADVISORY AGREEMENT (the "Agreement") is made this 1st
day of July, 1997, between JANUS INVESTMENT FUND, a Massachusetts business trust
(the "Trust"), and JANUS CAPITAL CORPORATION, a Colorado corporation ("JCC").

                              W I T N E S S E T H:

     WHEREAS, the Trust is registered as an open-end management investment
company under the Investment Company Act of 1940, as amended (the "1940 Act"),
and has registered its shares for public offering under the Securities Act of
1933, as amended (the "1933 Act"); and

     WHEREAS, the Trust is authorized to create separate funds, each with
its own separate investment portfolio of which the beneficial interests are
represented by a separate series of shares of the Trust; one of such funds
created by the Trust being designated as the Janus Tax-Exempt Money Market Fund
(the "Fund"); and

     WHEREAS, the Trust and JCC have entered into a separate agreement for the
provision of administrative services; and

     WHEREAS, the Trust and JCC deem it mutually advantageous that JCC
should assist the Trustees and officers of the Trust in the management of the
securities portfolio of the Fund as described below.

     NOW, THEREFORE, the parties agree as follows:

     1.   Investment Advisory Services. JCC shall furnish continuous advice
and recommendations to the Fund as to the acquisition, holding or disposition of
any or all of the securities or other assets which the Fund may own or
contemplate acquiring from time to time. JCC shall give due consideration to the
investment policies and restrictions and the other statements concerning the
Fund in the Trust's declaration of trust, bylaws, and registration statements
under the 1940 Act and the 1933 Act (as they may be supplemented from time to
time and as authorized by the Trustees), to policies and directives affecting
the Fund adopted by the Trustees, and to the provisions of the Internal Revenue
Code, as amended from time to time, applicable to the Fund as a regulated
investment company. In addition, JCC shall cause its officers to attend meetings
and furnish oral or written reports, as the Trust may reasonably require, in
order to keep the Trustees and appropriate officers of the Trust fully informed
as to the condition of the investment portfolio of the Fund, the investment
recommendations of JCC, and the investment considerations which have given


                                     - 1 -

<PAGE>


rise to those recommendations. JCC shall supervise the purchase and sale of
securities and other obligations and related brokerage and dealer relationships
as directed by the appropriate officers of the Trust.

     2.   Other Services. JCC is hereby authorized, subject to review by the
Trustees, to furnish or arrange for such other services as JCC shall from time
to time determine to be necessary or useful to perform the services specifically
contemplated by this Agreement.

     3.   Obligations of Trust. The Trust shall have the following obligations
under this Agreement:

          a.   to keep JCC continuously and fully informed as to the 
               composition of its investment portfolio and the nature of all of
               its assets and liabilities from time to time;

          b.   to furnish JCC with a certified copy of any financial
               statement or report prepared for it by certified or
               independent public accountants and with copies of any
               financial statements or reports made to its
               shareholders or to any governmental body or
               securities exchange;

          c.   to furnish JCC with any further materials or
               information which JCC may reasonably request to
               enable it to perform its functions under this
               Agreement; and

          d.   to compensate JCC for its services and reimburse JCC
               for its expenses incurred hereunder in accordance
               with the provisions hereof.

     4.   Compensation. The Trust shall pay to JCC for its investment advisory
services a fee, payable in arrears on the last day of each month during which or
part of which this Agreement is in effect, at the rate of 1/365 of 0.20% of the
aggregate closing net asset value of the shares of the Fund for each day of such
month. For the month during which this Agreement becomes effective and the month
during which it terminates, however, there shall be an appropriate proration of
the fee payable for such month based on the number of calendar days of such
month during which this Agreement is effective.

     5.   Expenses Borne by the Trust. The Trust shall bear all expenses
incidental to the operation of the Fund.

     6.   Treatment of Investment Advice. The Trust shall treat the investment
advice and recommendations of JCC as being advisory only, and shall retain full
control over its own investment policies. However, the Trustees may delegate to
the appropriate officers of the Trust, or to a committee of the Trustees, the
power to authorize purchases, sales or other actions affecting the portfolio of
the Fund.


                                     - 2 -

<PAGE>


     7.   Termination. This Agreement may be terminated at any time, without
penalty, by the Trustees of the Trust, or by the shareholders of the Trust
acting by vote of at least a majority of its outstanding voting securities,
provided in either case that sixty (60) days advance written notice of
termination be given to JCC at its principal place of business. This Agreement
may be terminated by JCC at any time, without penalty, by giving sixty (60) days
advance written notice of termination to the Trust, addressed to its principal
place of business. The Trust agrees that, consistent with the terms of the
Trust's Declaration of Trust, the Trust shall cease to use the name "Janus" in
connection with the Fund as soon as reasonably practicable following any
termination of this Agreement if JCC does not continue to provide investment
advice to the Fund after such termination.

     8.   Assignment. This Agreement shall terminate automatically in the
event of any assignment of this Agreement.

     9.   Term. This Agreement shall continue in effect until July 1, 1998,
unless sooner terminated in accordance with its terms, and shall continue in
effect from year to year thereafter only so long as such continuance is
specifically approved at least annually by the vote of a majority of the
Trustees of the Trust, including a majority of those Trustees who are not
parties hereto or interested persons of any such party, cast in person at a
meeting called for the purpose of voting on the approval of the terms of such
renewal, or by the affirmative vote of a majority of the outstanding voting
securities of the Trust; provided, however, that if this Agreement or the
continuation of this Agreement is not approved by the Fund, JCC may continue to
render to the Fund the services described herein in the manner and to the extent
permitted by the 1940 Act and regulations thereunder. The annual approvals
provided for herein shall be effective to continue this Agreement in effect from
year to year if given within a period beginning not more than ninety (90) days
prior to July 1 of each applicable year, notwithstanding the fact that more than
three hundred sixty-five (365) days may have elapsed since the date on which
such approval was last given.

     10.  Amendments. This Agreement may be amended by the parties only if
such amendment is specifically approved (a) by a majority of the Trustees,
including a majority of the Trustees who are not interested persons of JCC and,
(b) if required by applicable law, by the affirmative vote of a majority of the
outstanding voting securities of the Fund.

     11.  Limitation of Personal Liability. All the parties hereto
acknowledge and agree that all liabilities of the Trust arising, directly or
indirectly, under this Agreement, of any and every nature whatsoever, shall be
satisfied solely out of the assets of the Fund and that no Trustee, officer or
holder of shares of beneficial interest of the Trust shall be personally liable
for any of the foregoing liabilities. The Trust's Declaration of Trust, as
amended from time to time, is on file in the Office of the Secretary of State of
the Commonwealth of Massachusetts. Such Declaration of Trust describes in detail
the respective responsibilities and limitations on liability of the Trustees,
officers and holders of shares of beneficial interest of the Trust.

     12.  Limitation of Liability of JCC. JCC shall not be liable for any
error of judgment or mistake of law, for any loss arising out of any investment,
or for any act or omission taken with


                                     - 3 -

<PAGE>


respect to the Trust, except for willful misfeasance, bad faith or gross
negligence in the performance of its duties, or by reason of reckless disregard
of its obligations and duties hereunder and except to the extent otherwise
provided by law. As used in this Section 12, "JCC" shall include any affiliate
of JCC performing services for the Trust contemplated hereunder and directors,
officers and employees of JCC and such affiliates.

     13.  Activities of JCC. The services of JCC to the Trust hereunder are
not to be deemed to be exclusive, and JCC and its affiliates are free to render
services to other parties. It is understood that trustees, officers and
shareholders of the Trust are or may become interested in JCC as directors,
officers and shareholders of JCC, that directors, officers, employees and
shareholders of JCC are or may become similarly interested in the Trust, and
that JCC may become interested in the Trust as a shareholder or otherwise.

     14.  Certain Definitions. The terms "vote of a majority of the
outstanding voting securities," "assignment" and "interested persons" when used
herein, shall have the respective meanings specified in the 1940 Act, as now in
effect or hereafter amended, and the rules and regulations thereunder, subject
to such orders, exemptions and interpretations as may be issued by the
Securities and Exchange Commission under said Act and as may be then in effect.

     IN WITNESS WHEREOF, the parties have caused their duly authorized
officers to execute this Investment Advisory Agreement as of the date and year
first above written.


                                        JANUS CAPITAL CORPORATION



                                        By: /s/ Steven R. Goodbarn
                                            Steven R. Goodbarn, Vice President


                                        JANUS INVESTMENT FUND



                                        By: /s/ Thomas H. Bailey
                                            Thomas H. Bailey, President


                                     - 4 -


                                                            EXHIBIT 5(i)


                             JANUS INVESTMENT FUND

                         INVESTMENT ADVISORY AGREEMENT

                             JANUS HIGH-YIELD FUND


     THIS INVESTMENT ADVISORY AGREEMENT (the "Agreement") is made this 1st
day of July, 1997, between JANUS INVESTMENT FUND, a Massachusetts business trust
(the "Trust"), and JANUS CAPITAL CORPORATION, a Colorado corporation ("JCC").

                              W I T N E S S E T H:

     WHEREAS, the Trust is registered as an open-end management investment
company under the Investment Company Act of 1940, as amended (the "1940 Act"),
and has registered its shares for public offering under the Securities Act of
1933, as amended (the "1933 Act"); and

     WHEREAS, the Trust is authorized to create separate funds, each with
its own separate investment portfolio of which the beneficial interests are
represented by a separate series of shares; one of such funds created by the
Trust being designated as the Janus High-Yield Fund (the "Fund"); and

     WHEREAS, the Trust and JCC deem it mutually advantageous that JCC
should assist the Board of Trustees and officers of the Trust in the management
of the securities portfolio of the Fund.

     NOW, THEREFORE, the parties agree as follows:

     1.   Investment Advisory Services. JCC shall furnish continuous advice
and recommendations to the Fund as to the acquisition, holding, or disposition
of any or all of the securities or other assets which the Fund may own or
contemplate acquiring from time to time. JCC shall give due consideration to the
investment policies and restrictions and the other statements concerning the
Fund in the Trust's declaration of trust, bylaws, and registration statements
under the 1940 Act and the 1933 Act, and to the provisions of the Internal
Revenue Code, as amended from time to time, applicable to the Fund as a
regulated investment company. In addition, JCC shall cause its officers to
attend meetings and furnish oral or written reports, as the Trust may reasonably
require, in order to keep the Board of Trustees and appropriate officers of the
Trust fully informed as to the condition of the investment portfolio of the
Fund, the investment recommendations of JCC, and the investment considerations
which have given rise to those recommendations. JCC shall supervise the purchase
and sale of securities as directed by the appropriate officers of the Trust.

     2.   Other Services. JCC is hereby authorized (to the extent the Trust
has not otherwise contracted) but not obligated (to the extent it so notifies
the Board of Trustees at least 60 days in advance), to perform (or arrange for
the performance by affiliates) the management (not to include


                                     - 1 -

<PAGE>


advisory) and administrative services necessary for the operation of the Fund.
JCC is specifically authorized, on behalf of the Trust, to conduct relations
with custodians, depositories, transfer and pricing agents, accountants,
attorneys, underwriters, brokers and dealers, corporate fiduciaries, insurers,
banks and such other persons in any such other capacity deemed by JCC to be
necessary or desirable. JCC shall generally monitor and report to Fund officers
the Fund's compliance with investment policies and restrictions as set forth in
the currently effective prospectus and statement of additional information
relating to the shares of the Fund under the Securities Act of 1933, as amended.
JCC shall make reports to the Trust's Board of Trustees of its performance of
services hereunder upon request therefor and furnish advice and recommendations
with respect to such other aspects of the business and affairs of the Fund as it
shall determine to be desirable. JCC is also authorized, subject to review by
the Board of Trustees, to furnish such other services as the Adviser shall from
time to time determine to be necessary or useful to perform the services
contemplated by this Agreement.

     3.   Obligations of Trust. The Trust shall have the following obligations
under this Agreement:

          (a)  to keep JCC continuously and fully informed as to the
               composition of its investment portfolio and the
               nature of all of its assets and liabilities from time
               to time;

          (b)  to furnish JCC with a certified copy of any financial
               statement or report prepared for it by certified or
               independent public accountants and with copies of any
               financial statements or reports made to its
               shareholders or to any governmental body or
               securities exchange;

          (c)  to furnish JCC with any further materials or
               information which JCC may reasonably request to
               enable it to perform its function under this
               Agreement; and

           (d) to compensate JCC for its services and reimburse JCC
               for its expenses incurred hereunder in accordance
               with the provisions hereof.

     4.   Compensation. The Trust shall pay to JCC for its investment advisory
services a fee, calculated and payable for each day that this Agreement is in
effect, of 1/365 of .75% of the first $300,000,000 of the daily closing net
asset value of the Fund, plus 1/365 of 0.65% of the daily closing net asset
value of the Fund in excess of $300,000,000. The fee shall be paid monthly.

     5.   Expenses Borne by JCC. In addition to the expenses which JCC may
incur in the performance of its investment advisory functions under this
Agreement, and the expenses which it may expressly undertake to incur and pay
under other agreements with the Trust or otherwise, JCC shall incur and pay the
following expenses relating to the Fund's operations without reimbursement from
the Fund:


                                     - 2 -

<PAGE>


          (a)  Reasonable compensation, fees and related expenses of
               the Trust's officers and its Trustees (the
               "Trustees"), except for such Trustees who are not
               interested persons of JCC;

          (b)  Rental of offices of the Trust; and

          (c)  All expenses of promoting the sale of shares of the Fund, other
               than expenses incurred in complying with federal and state laws
               and the law of any foreign country or territory or other
               jurisdiction applicable to the issue, offer or sale of shares of
               the Fund including without limitation registration fees and
               costs, the costs of preparing the Fund's registration statement 
               and amendments thereto, and the costs and expenses of preparing,
               printing, and mailing prospectuses (and statements of additional
               information) to persons other than shareholders of the Fund.

     6.   Expenses Borne by the Trust. The Trust assumes and shall pay all
expenses incidental to its organization, operations and business not
specifically assumed or agreed to be paid by JCC pursuant to Sections 2 and 5
hereof, including, but not limited to, investment adviser fees; any
compensation, fees, or reimbursements which the Trust pays to its Trustees who
are not interested persons of JCC; compensation of the Fund's custodian,
transfer agent, registrar and dividend disbursing agent; legal, accounting,
audit and printing expenses; administrative, clerical, recordkeeping and
bookkeeping expenses; brokerage commissions and all other expenses in connection
with execution of portfolio transactions (including any appropriate commissions
paid to JCC or its affiliates for effecting exchange listed, over-the-counter or
other securities transactions); interest; all federal, state and local taxes
(including stamp, excise, income and franchise taxes); costs of stock
certificates and expenses of delivering such certificates to the purchaser
thereof; expenses of local representation in Massachusetts; expenses of
shareholders' meetings and of preparing, printing and distributing proxy
statements, notices, and reports to shareholders; expenses of preparing and
filing reports and tax returns with federal and state regulatory authorities;
all expenses incurred in complying with all federal and state laws and the laws
of any foreign country applicable to the issue, offer, or sale of shares of the
Fund, including, but not limited to, all costs involved in the registration or
qualification of shares of the Fund for sale in any jurisdiction, the costs of
portfolio pricing services and systems for compliance with blue sky laws, and
all costs involved in preparing, printing and mailing prospectuses and
statements of additional information of the Fund; and all fees, dues and other
expenses incurred by the Trust in connection with the membership of the Trust in
any trade association or other investment company organization. To the extent
that JCC shall perform any of the above described administrative and clerical
functions, including transfer agency, registry, dividend disbursing,
recordkeeping, bookkeeping, accounting and blue sky monitoring and registration
functions, and the preparation of reports and returns, the Trust shall pay to
JCC compensation for, or reimburse JCC for its expenses incurred in connection
with, such services as JCC and the Trust shall agree from time to time, any
other provision of this Agreement notwithstanding.


                                     - 3 -

<PAGE>


     7.   Treatment of Investment Advice. The Trust shall treat the investment
advice and recommendations of JCC as being advisory only, and shall retain full
control over its own investment policies. However, the Trustees may delegate to
the appropriate officers of the Trust, or to a committee of the Trustees, the
power to authorize purchases, sales or other actions affecting the portfolio of
the Fund in the interim between meetings of the Trustees.

     8.   Termination. This Agreement may be terminated at any time, without
penalty, by the Board of Trustees of the Trust, or by the shareholders of the
Fund acting by vote of at least a majority of its outstanding voting securities,
provided in either case that sixty (60) days advance written notice of
termination be given to JCC at its principal place of business. This Agreement
may be terminated by JCC at any time, without penalty, by giving sixty (60) days
advance written notice of termination to the Trust, addressed to its principal
place of business. The Trust agrees that, consistent with the terms of the
Trust's Declaration of Trust, the Trust shall cease to use the name "Janus" in
connection with the Fund as soon as reasonably practicable following any
termination of this Agreement if JCC does not continue to provide investment
advice to the Fund after such termination.

     9.   Assignment. This Agreement shall terminate automatically in the
event of any assignment of this Agreement.

     10.  Term. This Agreement shall continue in effect until July 1, 1998,
unless sooner terminated in accordance with its terms, and shall continue in
effect from year to year thereafter only so long as such continuance is
specifically approved at least annually by the vote of a majority of the
Trustees of the Trust who are not parties hereto or interested persons of any
such party, cast in person at a meeting called for the purpose of voting on the
approval of the terms of such renewal, and by either the Board of Trustees of
the Trust or the affirmative vote of a majority of the outstanding voting
securities of the Fund. The annual approvals provided for herein shall be
effective to continue this Agreement from year to year if given within a period
beginning not more than sixty (60) days prior to July 1 of each applicable year,
notwithstanding the fact that more than three hundred sixty-five (365) days may
have elapsed since the date on which such approval was last given.

     11.  Amendments. This Agreement may be amended by the parties only if
such amendment is specifically approved (i) by a majority of the Trustees,
including a majority of the Trustees who are not interested persons of JCC and,
if required by applicable law, (ii) by the affirmative vote of a majority of the
outstanding voting securities of the Fund.

     12.  Other Series. The Trustees shall determine the basis for making an
appropriate allocation of the Trust's expenses (other than those directly
attributable to the Fund) between the Fund and the other series of the Trust.

     13.  Limitation of Personal Liability. All the parties hereto
acknowledge and agree that all liabilities of the Trust arising, directly or
indirectly, under this Agreement, of any and every


                                     - 4 -

<PAGE>


nature whatsoever, shall be satisfied solely out of the assets of the Fund and
that no Trustee, officer or holder of shares of beneficial interest of the Trust
shall be personally liable for any of the foregoing liabilities. The Trust's
Declaration of Trust, as amended from time to time, is on file in the Office of
the Secretary of State of the Commonwealth of Massachusetts. Such Declaration of
Trust describes in detail the respective responsibilities and limitations on
liability of the Trustees, officers and holders of shares of beneficial interest
of the Trust.

     14.  Limitation of Liability of JCC. JCC shall not be liable for any
error of judgment or mistake of law or for any loss arising out of any
investment or for any act or omission taken with respect to the Trust, except
for willful misfeasance, bad faith or gross negligence in the performance of its
duties, or by reason of reckless disregard of its obligations and duties
hereunder and except to the extent otherwise provided by law. As used in this
Section 15, "JCC" shall include any affiliate of JCC performing services for the
Trust contemplated hereunder and directors, officers and employees of JCC and
such affiliates.

     15.  Activities of JCC. The services of JCC to the Trust hereunder are
not to be deemed to be exclusive, and JCC and its affiliates are free to render
services to other parties. It is understood that trustees, officers and
shareholders of the Trust are or may become interested in JCC as directors,
officers and shareholders of JCC, that directors, officers, employees and
shareholders of JCC are or may become similarly interested in the Trust, and
that JCC may become interested in the Trust as a shareholder or otherwise.

     16.  Certain Definitions. The terms "vote of a majority of the
outstanding voting securities," "assignment" and "interested persons" when used
herein, shall have the respective meanings specified in the 1940 Act, as now in
effect or hereafter amended, and the rules and regulations thereunder, subject
to such orders, exemptions and interpretations as may be issued by the
Securities and Exchange Commission under said Act and as may be then in effect.

     IN WITNESS WHEREOF, the parties have caused their duly authorized
officers to execute this Investment Advisory Agreement as of this 1st day of
July, 1997.

                                        JANUS CAPITAL CORPORATION



                                        By: /s/ Steven R. Goodbarn
                                            Steven R. Goodbarn, Vice President

                                        JANUS INVESTMENT FUND



                                        By: /s/ Thomas H. Bailey
                                            Thomas H. Bailey, President


                                     - 5 -



                                                       EXHIBIT 5(j)


                             JANUS INVESTMENT FUND

                         INVESTMENT ADVISORY AGREEMENT

                               JANUS OLYMPUS FUND


         THIS INVESTMENT ADVISORY AGREEMENT (the "Agreement") is made this 1st
day of July, 1997, between JANUS INVESTMENT FUND, a Massachusetts business trust
(the "Trust"), and JANUS CAPITAL CORPORATION, a Colorado corporation ("JCC").

                              W I T N E S S E T H:

     WHEREAS, the Trust is registered as an open-end management investment
company under the Investment Company Act of 1940, as amended (the "1940 Act"),
and has registered its shares for public offering under the Securities Act of
1933, as amended (the "1933 Act"); and

     WHEREAS, the Trust is authorized to create separate funds, each with
its own separate investment portfolio of which the beneficial interests are
represented by a separate series of shares; one of such funds created by the
Trust being designated as the Janus Olympus Fund (the "Fund"); and

     WHEREAS, the Trust and JCC deem it mutually advantageous that JCC
should assist the Trustees and officers of the Trust in the management of the
securities portfolio of the Fund.

     NOW, THEREFORE, the parties agree as follows:

     1.   Investment Advisory Services. JCC shall furnish continuous advice
and recommendations to the Fund as to the acquisition, holding, or disposition
of any or all of the securities or other assets which the Fund may own or
contemplate acquiring from time to time. JCC shall give due consideration to the
investment policies and restrictions and the other statements concerning the
Fund in the Trust's declaration of trust, bylaws, and registration statements
under the 1940 Act and the 1933 Act, and to the provisions of the Internal
Revenue Code, as amended from time to time, applicable to the Fund as a
regulated investment company. In addition, JCC shall cause its officers to
attend meetings and furnish oral or written reports, as the Trust may reasonably
require, in order to keep the Trustees and appropriate officers of the Trust
fully informed as to the condition of the investment portfolio of the Fund, the
investment recommendations of JCC, and the investment considerations which have
given rise to those recommendations. JCC shall supervise the purchase and sale
of securities as directed by the appropriate officers of the Trust.

     2.   Other Services. JCC is hereby authorized (to the extent the Trust
has not otherwise contracted) but not obligated (to the extent it so notifies
the Trustees at least 60 days in advance), to perform (or arrange for the
performance by affiliates) the management (not to include advisory)


                                     - 1 -

<PAGE>


and administrative services necessary for the operation of the Fund. JCC is
specifically authorized, on behalf of the Trust, to conduct relations with
custodians, depositories, transfer and pricing agents, accountants, attorneys,
underwriters, brokers and dealers, corporate fiduciaries, insurers, banks and
such other persons in any such other capacity deemed by JCC to be necessary or
desirable. JCC shall generally monitor and report to Fund officers the Fund's
compliance with investment policies and restrictions as set forth in the
currently effective prospectus and statement of additional information relating
to the shares of the Fund under the Securities Act of 1933, as amended. JCC
shall make reports to the Trustees of its performance of services hereunder upon
request therefor and furnish advice and recommendations with respect to such
other aspects of the business and affairs of the Fund as it shall determine to
be desirable. JCC is also authorized, subject to review by the Trustees, to
furnish such other services as JCC shall from time to time determine to be
necessary or useful to perform the services contemplated by this Agreement.

     3.   Obligations of Trust. The Trust shall have the following obligations
under this Agreement:

          (a)  to keep JCC continuously and fully informed as to the
               composition of its investment portfolio and the
               nature of all of its assets and liabilities from time
               to time;

          (b)  to furnish JCC with a certified copy of any financial
               statement or report prepared for it by certified or
               independent public accountants and with copies of any
               financial statements or reports made to its
               shareholders or to any governmental body or
               securities exchange;

          (c)  to furnish JCC with any further materials or
               information which JCC may reasonably request to
               enable it to perform its function under this
               Agreement; and

          (d)  to compensate JCC for its services and reimburse JCC
               for its expenses incurred hereunder in accordance
               with the provisions hereof.

     4.   Compensation. The Trust shall pay to JCC for its investment advisory
services a fee, calculated and payable for each day that this Agreement is in
effect, of 1/365 of 0.75% of the first $300,000,000 of the daily closing net
asset value of the Fund, plus 1/365 of 0.70% of the next $200,000,000 of the
daily closing net asset value of the Fund, plus 1/365 of 0.65% of the daily
closing net asset value of the Fund in excess of $500,000,000. The fee shall be
paid monthly.

     5.   Expenses Borne by JCC. In addition to the expenses which JCC may
incur in the performance of its investment advisory functions under this
Agreement, and the expenses which it may expressly undertake to incur and pay
under other agreements with the Trust or otherwise, JCC shall incur and pay the
following expenses relating to the Fund's operations without reimbursement from
the Fund:


                                     - 2 -

<PAGE>


          (a)  Reasonable compensation, fees and related expenses of
               the Trust's officers and its Trustees, except for
               such Trustees who are not interested persons of JCC;

          (b)  Rental of offices of the Trust; and

          (c)  All expenses of promoting the sale of shares of the Fund, other
               than expenses incurred in complying with federal and state laws 
               and the law of any foreign country or territory or other 
               jurisdiction applicable to the issue, offer or sale of shares of
               the Fund including without limitation registration fees and 
               costs, the costs of preparing the Fund's registration statement
               and amendments thereto, and the costs and expenses of preparing,
               printing, and mailing prospectuses (and statements of additional
               information) to persons other than shareholders of the Fund.

     6.   Expenses Borne by the Trust. The Trust assumes and shall pay all
expenses incidental to its organization, operations and business not
specifically assumed or agreed to be paid by JCC pursuant to Sections 2 and 5
hereof, including, but not limited to, investment adviser fees; any
compensation, fees, or reimbursements which the Trust pays to its Trustees who
are not interested persons of JCC; compensation of the Fund's custodian,
transfer agent, registrar and dividend disbursing agent; legal, accounting,
audit and printing expenses; administrative, clerical, recordkeeping and
bookkeeping expenses; brokerage commissions and all other expenses in connection
with execution of portfolio transactions (including any appropriate commissions
paid to JCC or its affiliates for effecting exchange listed, over-the-counter or
other securities transactions); interest; all federal, state and local taxes
(including stamp, excise, income and franchise taxes); costs of stock
certificates and expenses of delivering such certificates to the purchaser
thereof; expenses of local representation in Massachusetts; expenses of
shareholders' meetings and of preparing, printing and distributing proxy
statements, notices, and reports to shareholders; expenses of preparing and
filing reports and tax returns with federal and state regulatory authorities;
all expenses incurred in complying with all federal and state laws and the laws
of any foreign country applicable to the issue, offer, or sale of shares of the
Fund, including, but not limited to, all costs involved in the registration or
qualification of shares of the Fund for sale in any jurisdiction, the costs of
portfolio pricing services and systems for compliance with blue sky laws, and
all costs involved in preparing, printing and mailing prospectuses and
statements of additional information of the Fund; and all fees, dues and other
expenses incurred by the Trust in connection with the membership of the Trust in
any trade association or other investment company organization. To the extent
that JCC shall perform any of the above described administrative and clerical
functions, including transfer agency, registry, dividend disbursing,
recordkeeping, bookkeeping, accounting and blue sky monitoring and registration
functions, and the preparation of reports and returns, the Trust shall pay to
JCC compensation for, or reimburse JCC for its expenses incurred in connection
with, such services as JCC and the Trust shall agree from time to time, any
other provision of this Agreement notwithstanding.


                                     - 3 -

<PAGE>


     7.   Treatment of Investment Advice. The Trust shall treat the investment
advice and recommendations of JCC as being advisory only, and shall retain full
control over its own investment policies. However, the Trustees may delegate to
the appropriate officers of the Trust, or to a committee of the Trustees, the
power to authorize purchases, sales or other actions affecting the portfolio of
the Fund in the interim between meetings of the Trustees.

     8.   Termination. This Agreement may be terminated at any time, without
penalty, by the Trustees of the Trust, or by the shareholders of the Fund acting
by vote of at least a majority of its outstanding voting securities, provided in
either case that sixty (60) days advance written notice of termination be given
to JCC at its principal place of business. This Agreement may be terminated by
JCC at any time, without penalty, by giving sixty (60) days advance written
notice of termination to the Trust, addressed to its principal place of
business. The Trust agrees that, consistent with the terms of the Trust's
Declaration of Trust, the Trust shall cease to use the name "Janus" in
connection with the Fund as soon as reasonably practicable following any
termination of this Agreement if JCC does not continue to provide investment
advice to the Fund after such termination.

     9.   Assignment. This Agreement shall terminate automatically in the
event of any assignment of this Agreement.

     10.  Term. This Agreement shall continue in effect until July 1, 1998,
unless sooner terminated in accordance with its terms, and shall continue in
effect from year to year thereafter only so long as such continuance is
specifically approved at least annually by the vote of a majority of the
Trustees of the Trust who are not parties hereto or interested persons of any
such party, cast in person at a meeting called for the purpose of voting on the
approval of the terms of such renewal, and by either the Trustees of the Trust
or the affirmative vote of a majority of the outstanding voting securities of
the Fund. The annual approvals provided for herein shall be effective to
continue this Agreement from year to year if given within a period beginning not
more than ninety (90) days prior to July 1 of each applicable year,
notwithstanding the fact that more than three hundred sixty-five (365) days may
have elapsed since the date on which such approval was last given.

     11.  Amendments. This Agreement may be amended by the parties only if
such amendment is specifically approved (i) by a majority of the Trustees,
including a majority of the Trustees who are not interested persons of JCC and,
if required by applicable law, (ii) by the affirmative vote of a majority of the
outstanding voting securities of the Fund.

     12.  Other Series. The Trustees shall determine the basis for making an
appropriate allocation of the Trust's expenses (other than those directly
attributable to the Fund) between the Fund and the other series of the Trust.

     13.  Limitation of Personal Liability. All the parties hereto
acknowledge and agree that all liabilities of the Trust arising, directly or
indirectly, under this Agreement, of any and every nature whatsoever, shall be
satisfied solely out of the assets of the Fund and that no Trustee, officer or
holder of shares of beneficial interest of the Trust shall be personally liable
for any of the


                                     - 4 -

<PAGE>


foregoing liabilities. The Trust's Declaration of Trust, as amended from time to
time, is on file in the Office of the Secretary of State of the Commonwealth of
Massachusetts. Such Declaration of Trust describes in detail the respective
responsibilities and limitations on liability of the Trustees, officers and
holders of shares of beneficial interest of the Trust.

     14.  Limitation of Liability of JCC. JCC shall not be liable for any
error of judgment or mistake of law or for any loss arising out of any
investment or for any act or omission taken with respect to the Trust, except
for willful misfeasance, bad faith or gross negligence in the performance of its
duties, or by reason of reckless disregard of its obligations and duties
hereunder and except to the extent otherwise provided by law. As used in this
Section 15, "JCC" shall include any affiliate of JCC performing services for the
Trust contemplated hereunder and directors, officers and employees of JCC and
such affiliates.

     15.  Activities of JCC. The services of JCC to the Trust hereunder are
not to be deemed to be exclusive, and JCC and its affiliates are free to render
services to other parties. It is understood that trustees, officers and
shareholders of the Trust are or may become interested in JCC as directors,
officers and shareholders of JCC, that directors, officers, employees and
shareholders of JCC are or may become similarly interested in the Trust, and
that JCC may become interested in the Trust as a shareholder or otherwise.

     16.  Certain Definitions. The terms "vote of a majority of the
outstanding voting securities," "assignment" and "interested persons" when used
herein, shall have the respective meanings specified in the 1940 Act, as now in
effect or hereafter amended, and the rules and regulations thereunder, subject
to such orders, exemptions and interpretations as may be issued by the
Securities and Exchange Commission under said Act and as may be then in effect.

     IN WITNESS WHEREOF, the parties have caused their duly authorized
officers to execute this Investment Advisory Agreement as of this 1st day of
July, 1997.

                                        JANUS CAPITAL CORPORATION



                                        By: /s/ Steven R. Goodbarn 
                                            Steven R. Goodbarn, Vice President


                                        JANUS INVESTMENT FUND



                                        By: /s/ Thomas H. Bailey
                                            Thomas H. Bailey, President


                                     - 5 -



                                                                 EXHIBIT 5(k)

                             JANUS INVESTMENT FUND

                         INVESTMENT ADVISORY AGREEMENT

                            JANUS EQUITY INCOME FUND


     THIS INVESTMENT ADVISORY AGREEMENT (the "Agreement") is made this 1st
day of July, 1997, between JANUS INVESTMENT FUND, a Massachusetts business trust
(the "Trust"), and JANUS CAPITAL CORPORATION, a Colorado corporation ("JCC").

                              W I T N E S S E T H:

     WHEREAS, the Trust is registered as an open-end management investment
company under the Investment Company Act of 1940, as amended (the "1940 Act"),
and has registered its shares for public offering under the Securities Act of
1933, as amended (the "1933 Act"); and

     WHEREAS, the Trust is authorized to create separate funds, each with
its own separate investment portfolio of which the beneficial interests are
represented by a separate series of shares; one of such funds created by the
Trust being designated as the Janus Equity Income Fund (the "Fund"); and

     WHEREAS, the Trust and JCC deem it mutually advantageous that JCC
should assist the Trustees and officers of the Trust in the management of the
securities portfolio of the Fund.

     NOW, THEREFORE, the parties agree as follows:

     1.   Investment Advisory Services. JCC shall furnish continuous advice
and recommendations to the Fund as to the acquisition, holding, or disposition
of any or all of the securities or other assets which the Fund may own or
contemplate acquiring from time to time. JCC shall give due consideration to the
investment policies and restrictions and the other statements concerning the
Fund in the Trust's declaration of trust, bylaws, and registration statements
under the 1940 Act and the 1933 Act, and to the provisions of the Internal
Revenue Code, as amended from time to time, applicable to the Fund as a
regulated investment company. In addition, JCC shall cause its officers to
attend meetings and furnish oral or written reports, as the Trust may reasonably
require, in order to keep the Trustees and appropriate officers of the Trust
fully informed as to the condition of the investment portfolio of the Fund, the
investment recommendations of JCC, and the investment considerations which have
given rise to those recommendations. JCC shall supervise the purchase and sale
of securities as directed by the appropriate officers of the Trust.

     2.   Other Services. JCC is hereby authorized (to the extent the Trust
has not otherwise contracted) but not obligated (to the extent it so notifies
the Trustees at least 60 days in advance), to perform (or arrange for the
performance by affiliates) the management (not to include advisory)


                                      - 1 -

<PAGE>


and administrative services necessary for the operation of the Fund. JCC is
specifically authorized, on behalf of the Trust, to conduct relations with
custodians, depositories, transfer and pricing agents, accountants, attorneys,
underwriters, brokers and dealers, corporate fiduciaries, insurers, banks and
such other persons in any such other capacity deemed by JCC to be necessary or
desirable. JCC shall generally monitor and report to Fund officers the Fund's
compliance with investment policies and restrictions as set forth in the
currently effective prospectus and statement of additional information relating
to the shares of the Fund under the Securities Act of 1933, as amended. JCC
shall make reports to the Trustees of its performance of services hereunder upon
request therefor and furnish advice and recommendations with respect to such
other aspects of the business and affairs of the Fund as it shall determine to
be desirable. JCC is also authorized, subject to review by the Trustees, to
furnish such other services as JCC shall from time to time determine to be
necessary or useful to perform the services contemplated by this Agreement.

     3.   Obligations of Trust. The Trust shall have the following obligations
under this Agreement:

          (a)  to keep JCC continuously and fully informed as to the
               composition of its investment portfolio and the
               nature of all of its assets and liabilities from time
               to time;

          (b)  to furnish JCC with a certified copy of any financial
               statement or report prepared for it by certified or
               independent public accountants and with copies of any
               financial statements or reports made to its
               shareholders or to any governmental body or
               securities exchange;

           (c) to furnish JCC with any further materials or
               information which JCC may reasonably request to
               enable it to perform its function under this
               Agreement; and

           (d) to compensate JCC for its services and reimburse JCC
               for its expenses incurred hereunder in accordance
               with the provisions hereof.

     4.   Compensation. The Trust shall pay to JCC for its investment advisory
services a fee, calculated and payable for each day that this Agreement is in
effect, of 1/365 of 0.75% of the first $300,000,000 of the daily closing net
asset value of the Fund, plus 1/365 of 0.70% of the next $200,000,000 of the
daily closing net asset value of the Fund, plus 1/365 of 0.65% of the daily
closing net asset value of the Fund in excess of $500,000,000. The fee shall be
paid monthly.

     5.   Expenses Borne by JCC. In addition to the expenses which JCC may
incur in the performance of its investment advisory functions under this
Agreement, and the expenses which it may expressly undertake to incur and pay
under other agreements with the Trust or otherwise, JCC shall incur and pay the
following expenses relating to the Fund's operations without reimbursement from
the Fund:


                                     - 2 -

<PAGE>


          (a)  Reasonable compensation, fees and related expenses of
               the Trust's officers and its Trustees, except for
               such Trustees who are not interested persons of JCC;

          (b)  Rental of offices of the Trust; and

          (c)  All expenses of promoting the sale of shares of the Fund, other
               than expenses incurred in complying with federal and state laws
               and the law of any foreign country or territory or other 
               jurisdiction applicable to the issue, offer or sale of shares
               of the Fund including without limitation registration fees and 
               costs, the costs of preparing the Fund's registration statement 
               and amendments thereto, and the costs and expenses of preparing,
               printing, and mailing prospectuses (and statements of additional
               information) to persons other than shareholders of the Fund.

     6.   Expenses Borne by the Trust. The Trust assumes and shall pay all
expenses incidental to its organization, operations and business not
specifically assumed or agreed to be paid by JCC pursuant to Sections 2 and 5
hereof, including, but not limited to, investment adviser fees; any
compensation, fees, or reimbursements which the Trust pays to its Trustees who
are not interested persons of JCC; compensation of the Fund's custodian,
transfer agent, registrar and dividend disbursing agent; legal, accounting,
audit and printing expenses; administrative, clerical, recordkeeping and
bookkeeping expenses; brokerage commissions and all other expenses in connection
with execution of portfolio transactions (including any appropriate commissions
paid to JCC or its affiliates for effecting exchange listed, over-the-counter or
other securities transactions); interest; all federal, state and local taxes
(including stamp, excise, income and franchise taxes); costs of stock
certificates and expenses of delivering such certificates to the purchaser
thereof; expenses of local representation in Massachusetts; expenses of
shareholders' meetings and of preparing, printing and distributing proxy
statements, notices, and reports to shareholders; expenses of preparing and
filing reports and tax returns with federal and state regulatory authorities;
all expenses incurred in complying with all federal and state laws and the laws
of any foreign country applicable to the issue, offer, or sale of shares of the
Fund, including, but not limited to, all costs involved in the registration or
qualification of shares of the Fund for sale in any jurisdiction, the costs of
portfolio pricing services and systems for compliance with blue sky laws, and
all costs involved in preparing, printing and mailing prospectuses and
statements of additional information of the Fund; and all fees, dues and other
expenses incurred by the Trust in connection with the membership of the Trust in
any trade association or other investment company organization. To the extent
that JCC shall perform any of the above described administrative and clerical
functions, including transfer agency, registry, dividend disbursing,
recordkeeping, bookkeeping, accounting and blue sky monitoring and registration
functions, and the preparation of reports and returns, the Trust shall pay to
JCC compensation for, or reimburse JCC for its expenses incurred in connection
with, such services as JCC and the Trust shall agree from time to time, any
other provision of this Agreement notwithstanding.


                                     - 3 -

<PAGE>


     7.   Treatment of Investment Advice. The Trust shall treat the investment
advice and recommendations of JCC as being advisory only, and shall retain full
control over its own investment policies. However, the Trustees may delegate to
the appropriate officers of the Trust, or to a committee of the Trustees, the
power to authorize purchases, sales or other actions affecting the portfolio of
the Fund in the interim between meetings of the Trustees.

     8.   Termination. This Agreement may be terminated at any time, without
penalty, by the Trustees of the Trust, or by the shareholders of the Fund acting
by vote of at least a majority of its outstanding voting securities, provided in
either case that sixty (60) days advance written notice of termination be given
to JCC at its principal place of business. This Agreement may be terminated by
JCC at any time, without penalty, by giving sixty (60) days advance written
notice of termination to the Trust, addressed to its principal place of
business. The Trust agrees that, consistent with the terms of the Trust's
Declaration of Trust, the Trust shall cease to use the name "Janus" in
connection with the Fund as soon as reasonably practicable following any
termination of this Agreement if JCC does not continue to provide investment
advice to the Fund after such termination.

     9.   Assignment. This Agreement shall terminate automatically in the
event of any assignment of this Agreement.

     10.  Term. This Agreement shall continue in effect until July 1, 1998,
unless sooner terminated in accordance with its terms, and shall continue in
effect from year to year thereafter only so long as such continuance is
specifically approved at least annually by the vote of a majority of the
Trustees of the Trust who are not parties hereto or interested persons of any
such party, cast in person at a meeting called for the purpose of voting on the
approval of the terms of such renewal, and by either the Trustees of the Trust
or the affirmative vote of a majority of the outstanding voting securities of
the Fund. The annual approvals provided for herein shall be effective to
continue this Agreement from year to year if given within a period beginning not
more than ninety (90) days prior to July 1 of each applicable year,
notwithstanding the fact that more than three hundred sixty-five (365) days may
have elapsed since the date on which such approval was last given.

     11.  Amendments. This Agreement may be amended by the parties only if
such amendment is specifically approved (i) by a majority of the Trustees,
including a majority of the Trustees who are not interested persons of JCC and,
if required by applicable law, (ii) by the affirmative vote of a majority of the
outstanding voting securities of the Fund.

     12.  Other Series. The Trustees shall determine the basis for making an
appropriate allocation of the Trust's expenses (other than those directly
attributable to the Fund) between the Fund and the other series of the Trust.

     13.  Limitation of Personal Liability. All the parties hereto
acknowledge and agree that all liabilities of the Trust arising, directly or
indirectly, under this Agreement, of any and every nature whatsoever, shall be
satisfied solely out of the assets of the Fund and that no Trustee, officer or
holder of shares of beneficial interest of the Trust shall be personally liable
for any of the


                                     - 4 -

<PAGE>


foregoing liabilities. The Trust's Declaration of Trust, as amended from time to
time, is on file in the Office of the Secretary of State of the Commonwealth of
Massachusetts. Such Declaration of Trust describes in detail the respective
responsibilities and limitations on liability of the Trustees, officers and
holders of shares of beneficial interest of the Trust.

     14.  Limitation of Liability of JCC. JCC shall not be liable for any
error of judgment or mistake of law or for any loss arising out of any
investment or for any act or omission taken with respect to the Trust, except
for willful misfeasance, bad faith or gross negligence in the performance of its
duties, or by reason of reckless disregard of its obligations and duties
hereunder and except to the extent otherwise provided by law. As used in this
Section 15, "JCC" shall include any affiliate of JCC performing services for the
Trust contemplated hereunder and directors, officers and employees of JCC and
such affiliates.

     15.  Activities of JCC. The services of JCC to the Trust hereunder are
not to be deemed to be exclusive, and JCC and its affiliates are free to render
services to other parties. It is understood that trustees, officers and
shareholders of the Trust are or may become interested in JCC as directors,
officers and shareholders of JCC, that directors, officers, employees and
shareholders of JCC are or may become similarly interested in the Trust, and
that JCC may become interested in the Trust as a shareholder or otherwise.

     16.  Certain Definitions. The terms "vote of a majority of the
outstanding voting securities," "assignment" and "interested persons" when used
herein, shall have the respective meanings specified in the 1940 Act, as now in
effect or hereafter amended, and the rules and regulations thereunder, subject
to such orders, exemptions and interpretations as may be issued by the
Securities and Exchange Commission under said Act and as may be then in effect.

     IN WITNESS WHEREOF, the parties have caused their duly authorized
officers to execute this Investment Advisory Agreement as of the date and year
first above written.


                                        JANUS CAPITAL CORPORATION



                                        By: /s/ Steven R. Goodbarn
                                            Steven R. Goodbarn, Vice President

                                        JANUS INVESTMENT FUND



                                        By: /s/ Thomas H. Bailey 
                                            Thomas H. Bailey, President


                                     - 5 -



                                                                 EXHIBIT 5(l) 

                             JANUS INVESTMENT FUND

                         INVESTMENT ADVISORY AGREEMENT

                         JANUS SPECIAL SITUATIONS FUND


     THIS INVESTMENT ADVISORY AGREEMENT (the "Agreement") is made this 1st
day of July, 1997, between JANUS INVESTMENT FUND, a Massachusetts business trust
(the "Trust"), and JANUS CAPITAL CORPORATION, a Colorado corporation ("JCC").

                              W I T N E S S E T H:

     WHEREAS, the Trust is registered as an open-end management investment
company under the Investment Company Act of 1940, as amended (the "1940 Act"),
and has registered its shares for public offering under the Securities Act of
1933, as amended (the "1933 Act"); and

     WHEREAS, the Trust is authorized to create separate funds, each with
its own separate investment portfolio of which the beneficial interests are
represented by a separate series of shares; one of such funds created by the
Trust being designated as the Janus Special Situations Fund (the "Fund"); and

     WHEREAS, the Trust and JCC deem it mutually advantageous that JCC
should assist the Trustees and officers of the Trust in the management of the
securities portfolio of the Fund.

     NOW, THEREFORE, the parties agree as follows:

     1.   Investment Advisory Services. JCC shall furnish continuous advice
and recommendations to the Fund as to the acquisition, holding, or disposition
of any or all of the securities or other assets which the Fund may own or
contemplate acquiring from time to time. JCC shall give due consideration to the
investment policies and restrictions and the other statements concerning the
Fund in the Trust's declaration of trust, bylaws, and registration statements
under the 1940 Act and the 1933 Act, and to the provisions of the Internal
Revenue Code, as amended from time to time, applicable to the Fund as a
regulated investment company. In addition, JCC shall cause its officers to
attend meetings and furnish oral or written reports, as the Trust may reasonably
require, in order to keep the Trustees and appropriate officers of the Trust
fully informed as to the condition of the investment portfolio of the Fund, the
investment recommendations of JCC, and the investment considerations which have
given rise to those recommendations. JCC shall supervise the purchase and sale
of securities as directed by the appropriate officers of the Trust.

     2.   Other Services. JCC is hereby authorized (to the extent the Trust
has not otherwise contracted) but not obligated (to the extent it so notifies
the Trustees at least 60 days in advance), to perform (or arrange for the
performance by affiliates) the management (not to include advisory)


                                     - 1 -

<PAGE>


and administrative services necessary for the operation of the Fund. JCC is
specifically authorized, on behalf of the Trust, to conduct relations with
custodians, depositories, transfer and pricing agents, accountants, attorneys,
underwriters, brokers and dealers, corporate fiduciaries, insurers, banks and
such other persons in any such other capacity deemed by JCC to be necessary or
desirable. JCC shall generally monitor and report to Fund officers the Fund's
compliance with investment policies and restrictions as set forth in the
currently effective prospectus and statement of additional information relating
to the shares of the Fund under the Securities Act of 1933, as amended. JCC
shall make reports to the Trustees of its performance of services hereunder upon
request therefor and furnish advice and recommendations with respect to such
other aspects of the business and affairs of the Fund as it shall determine to
be desirable. JCC is also authorized, subject to review by the Trustees, to
furnish such other services as JCC shall from time to time determine to be
necessary or useful to perform the services contemplated by this Agreement.

     3.   Obligations of Trust. The Trust shall have the following obligations
under this Agreement:

          (a)  to keep JCC continuously and fully informed as to the
               composition of its investment portfolio and the
               nature of all of its assets and liabilities from time
               to time;

          (b) to furnish JCC with a certified copy of any financial
               statement or report prepared for it by certified or
               independent public accountants and with copies of any
               financial statements or reports made to its
               shareholders or to any governmental body or
               securities exchange;

          (c) to furnish JCC with any further materials or
               information which JCC may reasonably request to
               enable it to perform its function under this
               Agreement; and

          (d)  to compensate JCC for its services and reimburse JCC
               for its expenses incurred hereunder in accordance
               with the provisions hereof.

     4.   Compensation. The Trust shall pay to JCC for its investment advisory
services a fee, calculated and payable for each day that this Agreement is in
effect, of 1/365 of 0.75% of the first $300,000,000 of the daily closing net
asset value of the Fund, plus 1/365 of 0.70% of the next $200,000,000 of the
daily closing net asset value of the Fund, plus 1/365 of 0.65% of the daily
closing net asset value of the Fund in excess of $500,000,000. The fee shall be
paid monthly.

     5.   Expenses Borne by JCC. In addition to the expenses which JCC may
incur in the performance of its investment advisory functions under this
Agreement, and the expenses which it may expressly undertake to incur and pay
under other agreements with the Trust or otherwise, JCC shall incur and pay the
following expenses relating to the Fund's operations without reimbursement from
the Fund:


                                     - 2 -

<PAGE>


          (a)  Reasonable compensation, fees and related expenses of
               the Trust's officers and its Trustees, except for
               such Trustees who are not interested persons of JCC;

          (b)  Rental of offices of the Trust; and

          (c)  All expenses of promoting the sale of shares of the Fund, other 
               than expenses  incurred in complying with federal and state laws
               and the law of any foreign country or territory or other
               jurisdiction applicable to the issue, offer or sale of shares of
               the Fund including without limitation registration fees and 
               costs, the costs of preparing the Fund's registration statement
               and amendments thereto, and the costs and expenses of preparing,
               printing, and mailing prospectuses (and statements of additional
               information) to persons other than shareholders of the Fund.

     6.   Expenses Borne by the Trust. The Trust assumes and shall pay all
expenses incidental to its organization, operations and business not
specifically assumed or agreed to be paid by JCC pursuant to Sections 2 and 5
hereof, including, but not limited to, investment adviser fees; any
compensation, fees, or reimbursements which the Trust pays to its Trustees who
are not interested persons of JCC; compensation of the Fund's custodian,
transfer agent, registrar and dividend disbursing agent; legal, accounting,
audit and printing expenses; administrative, clerical, recordkeeping and
bookkeeping expenses; brokerage commissions and all other expenses in connection
with execution of portfolio transactions (including any appropriate commissions
paid to JCC or its affiliates for effecting exchange listed, over-the-counter or
other securities transactions); interest; all federal, state and local taxes
(including stamp, excise, income and franchise taxes); costs of stock
certificates and expenses of delivering such certificates to the purchaser
thereof; expenses of local representation in Massachusetts; expenses of
shareholders' meetings and of preparing, printing and distributing proxy
statements, notices, and reports to shareholders; expenses of preparing and
filing reports and tax returns with federal and state regulatory authorities;
all expenses incurred in complying with all federal and state laws and the laws
of any foreign country applicable to the issue, offer, or sale of shares of the
Fund, including, but not limited to, all costs involved in the registration or
qualification of shares of the Fund for sale in any jurisdiction, the costs of
portfolio pricing services and systems for compliance with blue sky laws, and
all costs involved in preparing, printing and mailing prospectuses and
statements of additional information of the Fund; and all fees, dues and other
expenses incurred by the Trust in connection with the membership of the Trust in
any trade association or other investment company organization. To the extent
that JCC shall perform any of the above described administrative and clerical
functions, including transfer agency, registry, dividend disbursing,
recordkeeping, bookkeeping, accounting and blue sky monitoring and registration
functions, and the preparation of reports and returns, the Trust shall pay to
JCC compensation for, or reimburse JCC for its expenses incurred in connection
with, such services as JCC and the Trust shall agree from time to time, any
other provision of this Agreement notwithstanding.



                                     - 3 -

<PAGE>


     7.   Treatment of Investment Advice. The Trust shall treat the investment
advice and recommendations of JCC as being advisory only, and shall retain full
control over its own investment policies. However, the Trustees may delegate to
the appropriate officers of the Trust, or to a committee of the Trustees, the
power to authorize purchases, sales or other actions affecting the portfolio of
the Fund in the interim between meetings of the Trustees.

     8.   Termination. This Agreement may be terminated at any time, without
penalty, by the Trustees of the Trust, or by the shareholders of the Fund acting
by vote of at least a majority of its outstanding voting securities, provided in
either case that sixty (60) days advance written notice of termination be given
to JCC at its principal place of business. This Agreement may be terminated by
JCC at any time, without penalty, by giving sixty (60) days advance written
notice of termination to the Trust, addressed to its principal place of
business. The Trust agrees that, consistent with the terms of the Trust's
Declaration of Trust, the Trust shall cease to use the name "Janus" in
connection with the Fund as soon as reasonably practicable following any
termination of this Agreement if JCC does not continue to provide investment
advice to the Fund after such termination.

     9.   Assignment. This Agreement shall terminate automatically in the
event of any assignment of this Agreement.

     10.  Term. This Agreement shall continue in effect until July 1, 1998,
unless sooner terminated in accordance with its terms, and shall continue in
effect from year to year thereafter only so long as such continuance is
specifically approved at least annually by the vote of a majority of the
Trustees of the Trust who are not parties hereto or interested persons of any
such party, cast in person at a meeting called for the purpose of voting on the
approval of the terms of such renewal, and by either the Trustees of the Trust
or the affirmative vote of a majority of the outstanding voting securities of
the Fund. The annual approvals provided for herein shall be effective to
continue this Agreement from year to year if given within a period beginning not
more than ninety (90) days prior to July 1 of each applicable year,
notwithstanding the fact that more than three hundred sixty-five (365) days may
have elapsed since the date on which such approval was last given.

     11.  Amendments. This Agreement may be amended by the parties only if
such amendment is specifically approved (i) by a majority of the Trustees,
including a majority of the Trustees who are not interested persons of JCC and,
if required by applicable law, (ii) by the affirmative vote of a majority of the
outstanding voting securities of the Fund.

     12.  Other Series. The Trustees shall determine the basis for making an
appropriate allocation of the Trust's expenses (other than those directly
attributable to the Fund) between the Fund and the other series of the Trust.

     13.  Limitation of Personal Liability. All the parties hereto
acknowledge and agree that all liabilities of the Trust arising, directly or
indirectly, under this Agreement, of any and every nature whatsoever, shall be
satisfied solely out of the assets of the Fund and that no Trustee, officer or
holder of shares of beneficial interest of the Trust shall be personally liable
for any of the


                                     - 4 -

<PAGE>


foregoing liabilities. The Trust's Declaration of Trust, as amended from time to
time, is on file in the Office of the Secretary of State of the Commonwealth of
Massachusetts. Such Declaration of Trust describes in detail the respective
responsibilities and limitations on liability of the Trustees, officers and
holders of shares of beneficial interest of the Trust.

     14.  Limitation of Liability of JCC. JCC shall not be liable for any
error of judgment or mistake of law or for any loss arising out of any
investment or for any act or omission taken with respect to the Trust, except
for willful misfeasance, bad faith or gross negligence in the performance of its
duties, or by reason of reckless disregard of its obligations and duties
hereunder and except to the extent otherwise provided by law. As used in this
Section 15, "JCC" shall include any affiliate of JCC performing services for the
Trust contemplated hereunder and directors, officers and employees of JCC and
such affiliates.

     15.  Activities of JCC. The services of JCC to the Trust hereunder are
not to be deemed to be exclusive, and JCC and its affiliates are free to render
services to other parties. It is understood that trustees, officers and
shareholders of the Trust are or may become interested in JCC as directors,
officers and shareholders of JCC, that directors, officers, employees and
shareholders of JCC are or may become similarly interested in the Trust, and
that JCC may become interested in the Trust as a shareholder or otherwise.

     16.  Certain Definitions. The terms "vote of a majority of the
outstanding voting securities," "assignment" and "interested persons" when used
herein, shall have the respective meanings specified in the 1940 Act, as now in
effect or hereafter amended, and the rules and regulations thereunder, subject
to such orders, exemptions and interpretations as may be issued by the
Securities and Exchange Commission under said Act and as may be then in effect.

     IN WITNESS WHEREOF, the parties have caused their duly authorized
officers to execute this Investment Advisory Agreement as of the date and year
first above written.

                                        JANUS CAPITAL CORPORATION



                                        By: /s/ Steven R. Goodbarn
                                            Steven R. Goodbarn, Vice President


                                         JANUS INVESTMENT FUND



                                         By: /s/ Thomas H. Bailey
                                             Thomas H. Bailey, President


                                     - 5 -



                                                                 EXHIBIT 6

                            DISTRIBUTION AGREEMENT


     THIS DISTRIBUTION AGREEMENT (the "Agreement"), made as of the 1st day of
July, 1997, by and between Janus Investment Fund, a business trust organized and
existing under the laws of the Commonwealth of Massachusetts, (hereinafter
called "JIF"), and Janus Distributors, Inc., a corporation organized and
existing under the laws of the State of Colorado (hereinafter called the
"Distributor" or "JDI"). This Agreement applies separately to each portfolio of
JIF whether now existing or hereafter created.


                                  WITNESSETH:

     WHEREAS, JIF is engaged in business as an open-end management investment
company registered under the Investment Company Act of 1940, as amended (the
"1940 Act"); and

     WHEREAS, the Distributor is registered as a broker-dealer under the
Securities Exchange Act of 1934, as amended (the "1934 Act") and the laws of
each state or jurisdiction in which the Distributor engages in business to the
extent such law requires, and is a member of the National Association of
Securities Dealers, Inc. (the "NASD") (such registrations and membership are
referred to collectively as the "Registrations"); and

     WHEREAS, JIF desires the Distributor to act as the underwriter for the
public offering of the shares of beneficial interest (hereinafter called
"Shares") of each of JIF's portfolios whether now existing or hereafter created
(hereinafter each called a "Fund" and collectively the "Funds").

     NOW, THEREFORE, in consideration of the premises and the mutual promises
hereinafter set forth, the parties hereto agree as follows:

     1.   Appointment. JIF appoints JDI to act as distributor of its Shares.

     2.   Delivery of Fund Documents. JIF has furnished the Distributor with
properly certified or authenticated copies of each of the following in effect on
the date hereof and shall furnish the Distributor from time to time properly
certified or authenticated copies of all amendments or supplements thereto:

     (a)  Agreement and Declaration of Trust;

     (b)  By-Laws; and

     (c)  Resolutions of the Board of Trustees (hereinafter referred to as the
          "Trustees") selecting the Distributor as distributor and approving
          this form of agreement and authorizing its execution.


                                      -1-

<PAGE>


     JIF shall furnish the Distributor promptly with copies of any registration
statements filed by it with the Securities and Exchange Commission (the "SEC")
under the Securities Act of 1933, as amended, (the "1933 Act") or the 1940 Act,
together with any financial statements and exhibits included therein, and all
amendments or supplements thereto hereafter filed.

     JIF shall also furnish the Distributor with such other certificates or
documents as the Distributor may from time to time, in its discretion,
reasonably deem necessary or appropriate in order to properly perform its duties
under this Agreement.

     3.   Solicitation of Orders for Purchase of Shares.

     (a)  Subject to the provisions of Paragraphs 4 and 7 hereof, and to such
minimum purchase requirements as may from time to time be indicated in each
Fund's Prospectus or Statement of Additional Information, the Distributor is
authorized to solicit, as agent on behalf of JIF, unconditional orders for
purchases of each Fund's Shares authorized for issuance and registered under the
1933 Act, provided that:

     (1)  The Distributor shall act solely as a disclosed agent on behalf of and
          for the account of JIF;

     (2)  The Distributor shall confirm or arrange with the transfer agent for
          the Shares to confirm all purchases of the Shares. Such confirmation
          shall conform to the requirements of Rule 10b-10 under the 1934 Act
          and shall clearly state that the Distributor is acting as agent in the
          transaction.

     (3)  The Distributor shall have no liability for payment for purchases of
          Shares it sells as agent; and

     (4)  Each order to purchase Shares of a Fund received by the Distributor
          shall be subject to acceptance by an officer of JIF and entry of the
          order on such Fund's records or shareholder accounts and is not
          binding until so accepted and entered.

     The purchase price of a Fund's Shares to the public shall be the public
offering price described in Paragraph 6 hereof.

     (b)  In consideration of the rights granted to the Distributor under this
Agreement, the Distributor will use its best efforts (but only in states and
jurisdictions in which the Distributor may lawfully do so) to solicit from
investors unconditional orders to purchase Shares of each Fund. JIF shall make
available to the Distributor without cost to the Distributor such number of
copies of each Fund's currently effective Prospectus and Statement of Additional
Information and copies of all information, financial statements and other papers
that the Distributor may reasonably request for use in connection with the
distribution of Shares.


                                      -2-

<PAGE>


     4.   Solicitation of Orders to Purchase Shares by Fund. The rights granted
to the Distributor shall be non-exclusive in that JIF reserves the right to
otherwise solicit purchases from, and sell Shares to, investors, including
without limitation the right to issue Shares in connection with the merger or
consolidation of any other investment company, trust or personal holding company
with a Fund, or a Fund's acquisition, by the purchase or otherwise, of all or
substantially all of the assets of an investment company, trust or personal
holding company, or substantially all of the outstanding shares or interests of
any such entity.

     5.   Payment of Expenses. The Distributor will not be entitled to any
compensation with respect to its services. JIF shall pay all charges of its
transfer, shareholder recordkeeping, dividend disbursing and redemption agents,
if any; all expenses of preparation, printing and mailing of confirmations; all
expenses of preparation and printing of annual or more frequent revisions of
each Fund's Prospectus and Statement of Additional Information and of supplying
copies thereof to shareholders; all expenses of registering and maintaining the
Registrations of JIF under the 1940 Act and the sale of JIF's Shares under the
1933 Act; all expenses of qualifying and maintaining qualifications of each Fund
and of the Shares for sale under securities laws of various states or other
jurisdictions and of registration and qualification of each Fund under all laws
applicable to JIF or its business activities.

     6.   Public Offering Price. All solicitations by the Distributor pursuant
to this Agreement shall be for orders to purchase Shares of a Fund at the public
offering price. The public offering price for each accepted subscription for a
Fund's Shares will be the net asset value per share next determined by JIF after
it accepts such subscription. The net asset value per share of the Shares shall
be determined in the manner provided in JIF's Declaration of Trust as now in
effect or as it may be amended, and as reflected in the then current Prospectus
and Statement of Additional Information covering the Shares.

     7.   Suspension of Sales. If and whenever the determination of a Fund's net
asset value is suspended and until such suspension is terminated, no further
orders for Shares shall be accepted by JIF except such unconditional orders
placed with JIF and accepted by it before the suspension. In addition, JIF
reserves the right to suspend sales of Shares of a Fund if, in the judgement of
the Trustees, it is in the best interest of the Fund to do so, such suspension
to continue for such period as may be determined by the Trustees; and in that
event, (i) at the direction of JIF, the Distributor shall suspend its
solicitation of orders to purchase Shares of such Fund until otherwise
instructed by JIF, and (ii) no orders to purchase Shares of such Fund shall be
accepted by JIF while such suspension remains in effect unless otherwise
directed by its Trustees.

     8.   Authorized Representations. The Distributor is not authorized by JIF
to give on behalf of any Fund any information or to make any representations in
connection with the sale of Shares other than the information and
representations contained in such Fund's registration statement filed with the
SEC under the 1933 Act and/or the 1940 Act, covering Shares, as such
registration statement or such Fund's Prospectus or Statement of Additional
Information may be amended or


                                      -3-
<PAGE>


supplemented from time to time, or contained in shareholder reports or other
material that may be prepared by or on behalf of such Fund or approved by such
Fund for the Distributor's use.

     9.   Registration of Additional Shares. JIF hereby agrees to register 
either (i) an indefinite number of Shares pursuant to Rule 24f-2 under the 1940
Act, or (ii) a definite number of Shares as JIF shall deem advisable pursuant
to Rule 24e-2 under the 1940 Act. JIF will, in cooperation with the Distributor,
take such action as may be necessary from time to time to qualify the Shares of
each Fund (so registered or otherwise qualified for sale under the 1933 Act), 
in any state or jurisdiction mutually agreeable to the Distributor and JIF, and
to maintain such qualification; provided, however, that nothing herein shall be
deemed to prevent JIF from registering the Shares without approval of the
Distributor in any state it deems appropriate.

     10.  Conformity With Law. The Distributor agrees that in soliciting orders
to purchase Shares it shall duly conform in all respects with applicable federal
and state laws and with the rules and regulations of the NASD. The Distributor
will use its best efforts to maintain its Registrations in good standing during
the term of this Agreement and will promptly notify JIF in the event of the
suspension or termination of any of the Registrations.

     11.  Independent Contractor. The Distributor shall be an independent
contractor and neither the Distributor, nor any of its officers, directors,
employees, or representatives is or shall be an employee of JIF in the
performance of the Distributor's duties hereunder. The Distributor shall be
responsible for its own conduct and the employment, control, and conduct of its
agents and employees and for injury to such agents or employees or to others
through its agents and employees and agrees to pay or to insure that persons
other than JIF will pay all employee taxes due with respect to the activities of
its agents and employees.

     12.  Indemnification. The Distributor agrees to indemnify and hold harmless
JIF and each of the Trustees and its officers, employees and representatives and
each person, if any, who controls JIF within the meaning of Section 15 of the
1933 Act against any and all losses, liabilities, damages, claims and expenses
(including the reasonable costs of investigating or defending any alleged loss,
liability, damage, claim or expense and reasonable legal counsel fees incurred
in connection therewith) to which JIF or such Trustees, officers, employees,
representatives, or controlling person or persons may become subject under the
1933 Act, under any other statute, at common law, or otherwise, arising out of
the acquisition of any Shares of any Fund by any person which (i) may be based
upon any wrongful act by the Distributor or any of the Distributor's directors,
officers, employees or representatives, or (ii) may be based upon any untrue
statement or alleged untrue statement of a material fact contained in a
registration statement, Prospectus, Statement of Additional Information,
shareholder report or other information covering Shares of such Fund filed or
made public by JIF or any amendment thereof or supplement thereto or the
omission or alleged omission to state therein a material fact required to be
stated therein or necessary to make the statements therein not misleading, if
such statement or omission was made in reliance upon information furnished to
such Fund by the Distributor in writing. In no case (i) is the Distributor's
indemnity in favor of JIF, or any person indemnified, to be deemed to protect
JIF or such


                                      -4-
<PAGE>


indemnified person against any liability to which JIF or such person would
otherwise be subject by reason of willful misfeasance, bad faith, or gross
negligence in the performance of its or such person's duties or by reason of its
or such person's reckless disregard of its or such person's obligations and
duties under this Agreement, or (ii) is the Distributor to be liable under its
indemnity agreement contained in this paragraph with respect to any claim made
against JIF or any person indemnified unless JIF or such person, as the case may
be, shall have notified the Distributor in writing of the claim within a
reasonable time after the summons, or other first written notification, giving
information of the nature of the claim served upon JIF or upon such person (or
after JIF or such person shall have received notice of such service on any
designated agent). However, failure to notify the Distributor of any such claim
shall not relieve the Distributor from any liability that the Distributor may
have to JIF or any person against whom such action is brought otherwise than on
account of the Distributor's indemnity agreement contained in this Paragraph.

     The Distributor shall be entitled to participate, at its own expense, in
the defense, or, if Distributor so elects, to assume the defense of any suit
brought to enforce any such claim but, if the Distributor elects to assume the
defense, such defense shall be conducted by legal counsel chosen by the
Distributor and satisfactory to the persons indemnified who are defendants in
the suit. In the event that the Distributor elects to assume the defense of any
such suit and retain such legal counsel, persons indemnified who are defendants
in the suit shall bear the fees and expenses of any additional legal counsel
retained by them. If the Distributor does not elect to assume the defense of any
such suit, the Distributor will reimburse persons indemnified who are defendants
in such suit for the reasonable fees of any legal counsel retained by them in
such litigation.

     JIF agrees to indemnify and hold harmless the Distributor and each of
its directors, officers, employees, and representatives and each person, if any,
who controls the Distributor within the meaning of Section 15 of the 1933 Act
against any and all losses, liabilities, damages, claims or expenses (including
the reasonable costs of investigating or defending any alleged loss, liability,
damage, claim or expenses and reasonable legal counsel fees incurred in
connection therewith) to which the Distributor or such of its directors,
officers, employees, representatives or controlling person or persons may become
subject under the 1933 Act, under any other statute, at common law, or otherwise
arising out of the acquisition of any Shares by any person which (i) may be
based upon any wrongful act by JIF or any of the Trustees, or JIF's officers,
employees or representatives other than the Distributor, or (ii) may be based
upon any untrue statement or alleged untrue statement of a material fact
contained in a registration statement, Prospectus, Statement of Additional
Information, shareholder report or other information covering Shares filed or
made public by JIF or any amendment thereof or supplement thereto, or the
omission or alleged omission to state therein a material fact required to be
stated therein or necessary to make the statements therein not misleading unless
such statement or omission was made in reliance upon information furnished by
the Distributor to JIF. In no case (i) is JIF's indemnity in favor of the
Distributor or any person indemnified to be deemed to protect the Distributor or
such indemnified person against any liability to which the Distributor or such
indemnified person would otherwise be subject by reason of willful misfeasance,
bad faith, or gross negligence in the performance of its or such person's duties
or by reason of its or such person's reckless disregard of its or such person's
obligations and duties under


                                      -5-

<PAGE>


this Agreement, or (ii) is JIF to be liable under its indemnity agreement
contained in this Paragraph with respect to any claim made against the
Distributor or any person indemnified unless the Distributor, or such person, as
the case may be, shall have notified JIF in writing of the claim within a
reasonable time after the summons, or other first written notification, giving
information of the nature of the claim served upon the Distributor or upon such
person (or after the Distributor or such person shall have received notice of
such service on any designated agent). However, failure to notify JIF of any
such claim shall not relieve JIF from any liability which JIF may have to the
Distributor or any person against whom such action is brought otherwise than on
account of JIF's indemnity agreement contained in this Paragraph.

     JIF shall be entitled to participate, at its own expense, in the
defense or, if JIF so elects, to assume the defense of any suit brought to
enforce such claim but, if JIF elects to assume the defense, such defense shall
be conducted by legal counsel chosen by JIF and satisfactory to the persons
indemnified who are defendants in the suit. In the event that JIF elects to
assume the defense of any such suit and retain such legal counsel, the persons
indemnified who are defendants in the suit shall bear the fees and expenses of
any additional legal counsel retained by them. If JIF does not elect to assume
the defense of any such suit, JIF will reimburse the persons indemnified who are
defendants in such suit for the reasonable fees and expenses of any legal
counsel retained by them in such litigation.

     13.  Duration and Termination of this Agreement. With respect to each
Fund and the Distributor, this Agreement shall become effective upon its
execution ("Effective Date") and unless terminated as provided herein, shall
remain in effect through July 1, 1998, and from year to year thereafter, but
only so long as such continuance is specifically approved at least annually (a)
by a vote of a majority of the Trustees who are not interested persons of the
Distributor or of the Fund, voting in person at a meeting called for the purpose
of voting on such approval, and (b) by the vote of either the Trustees or a
majority of the outstanding shares of the Fund. If the continuance of this
Agreement is not approved as to a Fund, the Distributor may continue to render
to that Fund the services described herein in the manner and to the extent
permitted by the 1940 Act and the rules and regulations thereunder, and this
Agreement shall continue with respect to those Funds that have approved its
continuance. This Agreement may be terminated by and between an individual Fund
and the Distributor at any time, without the payment of any penalty (a) on 60
days' written notice, by the Trustees or by a vote of a majority of the
outstanding Shares of such Fund, or by the Distributor, or (b) immediately, on
written notice by the Trustees, in the event of termination or suspension of any
of the Registrations. This Agreement will automatically terminate in the event
of its assignment.

     In interpreting the provisions of this Paragraph 13, the definitions
contained in Section 2(a) of the 1940 Act (particularly the definitions of
"interested person", "assignment", and "majority of the outstanding shares")
shall be applied.

     14.  Amendment of this Agreement. No provision of this Agreement may be
changed, waived, discharged, or terminated orally, but only by an instrument in
writing signed by each party


                                      -6-

<PAGE>


against which enforcement of the change, waiver, discharge, or termination is
sought. If JIF should at any time deem it necessary or advisable in the best
interests of a Fund that any amendment of this Agreement be made in order to
comply with the recommendations or requirements of the SEC or any other
governmental authority or to obtain any advantage under state or Federal or tax
laws and notifies the Distributor of the form of such amendment, and the reasons
therefore, and if the Distributor should decline to assent to such amendment,
JIF may terminate this Agreement as to that Fund forthwith. If the Distributor
should at any time request that a change be made in JIF's Agreement and
Declaration of Trust or By-Laws or in its methods of doing business, or in the
registration statement, the Prospectus or the Statement of Additional
Information of any Fund, in order to comply with any requirements of Federal or
state law or regulations of the SEC, or of a national securities association of
which the Distributor is or may be a member, relating to the sale of Shares, and
JIF should not make such necessary changes within a reasonable time, the
Distributor may terminate this Agreement as to that Fund forthwith.

     15.  Limitation of Personal Liability. The parties to this Agreement
acknowledge and agree that all liabilities of JIF arising, directly or
indirectly, under this Agreement, of any and every nature whatsoever, shall be
satisfied solely out of the assets of JIF and that no Trustee, officer or holder
of shares of beneficial interest of JIF shall be personally liable for any of
such liabilities. JIF's Agreement and Declaration of Trust, as amended from time
to time, is on file in the Office of the Secretary of State of The Commonwealth
of Massachusetts, and describes in detail the respective responsibilities and
limitations on liability of the Trustees, officers and holders of shares of
beneficial interest of JIF.

     16.  Notification by JIF. JIF agrees to advise the Distributor immediately:

          (a)  of any request by the SEC for amendments to JIF's Registration
Statement insofar as it relates to any of the Funds, the Prospectus or the 
Statement of Additional Information or for additional information,

          (b)  in the event of the issuance by the SEC of any stop order
suspending the effectiveness of JIF's Registration Statement insofar as it
relates to any of the Funds, the Prospectus or the Statement of Additional
Information or the initiation of any proceeding for that purpose,

          (c)  of the occurrence of any material event which makes untrue
any statement made in JIF's Registration Statement insofar as it relates to any
of the Funds, the Prospectus or the Statement of Additional Information or which
requires the making of a change in order to make the statements therein not
misleading and

          (d)  of all actions of the SEC with respect to any amendments
to JIF's Registration Statement insofar as it related to any of the Funds, the
Prospectus or the Statement of Additional Information which may from time to
time be filed with the SEC under the 1933 Act.


                                      -7-

<PAGE>


     17.  Miscellaneous. The captions in this Agreement are included for
convenience of reference only, and in no way define or limit any of the
provisions hereof or otherwise affect their construction or effect. This
Agreement may be executed simultaneously in two or more counterparts, each of
which shall be deemed an original, but all of which together shall constitute
one and the same instrument.

     18.  Notice. Any notice required or permitted to be given by a party to
this Agreement or to any other party hereunder shall be deemed sufficient if
delivered in person or sent by registered or certified mail, postage prepaid,
addressed by the party giving notice to each such other party at the address
provided below or to the last address furnished by each such other party to the
party giving notice.

     If to JIF:                         100 Fillmore Street
                                        Denver, Colorado 80206-4928
                                        Attn:  Secretary


     If to the Distributor:             100 Fillmore Street
                                        Denver, Colorado 80206-4928
                                        Attn:  Secretary

     IN WITNESS WHEREOF, the parties have executed this Agreement on the day
and year first above written.

ATTEST:                                 JANUS DISTRIBUTORS, INC.



/s/ Barbara Sue Vreeland                 By: /s/ Kelley Abbott Howes
                                             Kelley Abbott Howes, President


ATTEST:                                 JANUS INVESTMENT FUND



/s/ Barbara Sue Vreeland                By: /s/ Thomas H. Bailey 
                                            Thomas H. Bailey, President



                                      -8-



                                                                      EXHIBIT 11

                       CONSENT OF INDEPENDENT ACCOUNTANTS



We  hereby  consent  to the  incorporation by reference in the Prospectus and 
Statement of Additional Information constituting parts of this Post-Effective
Amendment No. 83 to the registration statement on Form N-1A (the "Registration
Statement") of our reports dated December 2, 1996, relating to the financial
statements and financial highlights appearing in the October 31, 1996 Annual
Reports to Shareholders of Janus Investment Fund, which are also incorporated
by reference into the Registration Statement.  We also consent to the references
to us  under  the  heading  "Financial Highlights" in the Prospectus and under 
the heading "Independent Accountants" in the Statement of Additional
Information.


/s/ Price Waterhouse LLP
PRICE WATERHOUSE LLP

Denver, Colorado
December 12, 1997


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