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028 D040600 0
028 E010600 186
028 E020600 0
028 E030600 0
028 E040600 391
028 F010600 61
028 F020600 0
028 F030600 0
028 F040600 257
028 G010600 1422
028 G020600 0
028 G030600 0
028 G040600 886
028 H000600 0
045 000600 Y
046 000600 N
047 000600 Y
048 000600 1.400
048 A010600 0
048 A020600 0.000
048 B010600 0
<PAGE> PAGE 21
048 B020600 0.000
048 C010600 0
048 C020600 0.000
048 D010600 0
048 D020600 0.000
048 E010600 0
048 E020600 0.000
048 F010600 0
048 F020600 0.000
048 G010600 0
048 G020600 0.000
048 H010600 0
048 H020600 0.000
048 I010600 0
048 I020600 0.000
048 J010600 0
048 J020600 0.000
048 K010600 0
048 K020600 0.000
062 A000600 N
062 B000600 0.0
062 C000600 0.0
062 D000600 0.0
062 E000600 0.0
062 F000600 0.0
062 G000600 0.0
062 H000600 0.0
062 I000600 0.0
062 J000600 0.0
062 K000600 0.0
062 L000600 0.0
062 M000600 0.0
062 N000600 0.0
062 O000600 0.0
062 P000600 0.0
062 Q000600 0.0
062 R000600 0.0
063 A000600 0
063 B000600 0.0
066 A000600 Y
066 C000600 Y
067 000600 N
068 A000600 N
068 B000600 Y
069 000600 N
070 A010600 Y
070 A020600 Y
070 B010600 N
070 B020600 N
070 C010600 N
070 C020600 N
<PAGE> PAGE 22
070 D010600 N
070 D020600 N
070 E010600 N
070 E020600 N
070 F010600 N
070 F020600 N
070 G010600 N
070 G020600 N
070 H010600 N
070 H020600 N
070 I010600 N
070 I020600 N
070 J010600 Y
070 J020600 N
070 K010600 Y
070 K020600 N
070 L010600 Y
070 L020600 Y
070 M010600 Y
070 M020600 Y
070 N010600 N
070 N020600 N
070 O010600 Y
070 O020600 N
070 P010600 N
070 P020600 N
070 Q010600 N
070 Q020600 N
070 R010600 N
070 R020600 N
071 A000600 8082
071 B000600 3926
071 C000600 2605
071 D000600 151
072 A000600 12
072 B000600 27
072 C000600 32
072 D000600 0
072 E000600 -2
072 F000600 35
072 G000600 0
072 H000600 0
072 I000600 8
072 J000600 45
072 K000600 0
072 L000600 0
072 M000600 6
072 N000600 4
072 O000600 0
072 P000600 0
072 Q000600 0
<PAGE> PAGE 23
072 R000600 33
072 S000600 17
072 T000600 0
072 U000600 4
072 V000600 0
072 W000600 7
072 X000600 159
072 Y000600 103
072 Z000600 1
072AA000600 282
072BB000600 1427
072CC010600 122
072CC020600 0
072DD010600 0
072DD020600 0
072EE000600 0
073 A010600 0.0000
073 A020600 0.0000
073 B000600 0.0000
073 C000600 0.0000
074 A000600 4
074 B000600 888
074 C000600 0
074 D000600 0
074 E000600 174
074 F000600 2969
074 G000600 0
074 H000600 0
074 I000600 0
074 J000600 0
074 K000600 29
074 L000600 27
074 M000600 0
074 N000600 4091
074 O000600 0
074 P000600 66
074 Q000600 0
074 R010600 0
074 R020600 0
074 R030600 0
074 R040600 271
074 S000600 0
074 T000600 3754
074 U010600 492
074 U020600 0
074 V010600 7.63
074 V020600 0.00
074 W000600 0.0000
074 X000600 222
074 Y000600 0
075 A000600 0
<PAGE> PAGE 24
075 B000600 3750
076 000600 0.00
SIGNATURE TERENCE M. SULLIVAN
TITLE VICE PRESIDENT
SUPPLEMENTARY REPORT OF INDEPENDENT AUDITORS
The Board of Directors and Shareholders
William Blair Mutual Funds, Inc.
In planning and performing our audit of the financial statements of
the William Blair Mutual Funds, Inc. consisting of the Growth Fund,
Value Discovery Fund, International Growth Fund, Emerging Markets Growth
Fund, Income Fund, and Ready Reserves Fund for the year ended
December 31, 1998, we considered their internal control, including
control activities for safeguarding securities, in order to determine
our auditing procedures for the purpose of expressing our opinion on
the financial statements and to comply with the requirements of Form
N-SAR, and not to provide assurance on internal control.
The management of William Blair Mutual Funds, Inc. is responsible for
establishing and maintaining internal control. In fulfilling this
responsibility, estimates and judgments by management are required to
assess the expected benefits and related costs of controls. Generally,
controls that are relevant to an audit pertain to the entity's objective
of preparing financial statements for external purposes that are fairly
presented in conformity with generally accepted accounting principles.
Those controls include the safeguarding of assets against unauthorized
acquisition, use or disposition.
Because of inherent limitations in internal control, errors or fraud
may occur and not be detected. Also, projection of any evaluation of
internal control to future periods is subject to the risk that it may
become inadequate because of changes in conditions or that the
effectiveness of the design and operation may deteriorate.
Our consideration of internal control would not necessarily disclose
all matters in internal control that might be material weaknesses under
standards established by the American Institute of Certified Public
Accountants. A material weakness is a condition in which the design or
operation of one or more of the specific internal control components
does not reduce to a relatively low level the risk that errors or fraud
in amounts that would be material in relation to the financial statements
being audited may occur and not be detected within a timely period by
employees in the normal course of performing their assigned functions.
However, we noted no matters involving internal control and its
operation, including controls for safeguarding securities, that we
consider to be material weaknesses as defined above at December 31, 1998.
This report is intended solely for the information and use of the
Board of Directors and management of the William Blair Mutual Funds, Inc.
and the Securities and Exchange Commission. and is not intended to be and
should not be used by anyone other than these specified parties.
Ernst & Young, LLP
Chicago, Illinois
February 2, 1999
