Exhibit 5.1
CONSENT OF INDEPENDENT ACCOUNTANTS
The Sponsors and Trustee of
Defined Asset Funds--Government Securities Income Fund--GNMA Series--1S
We consent to the use in this Post-Effective Amendment No. 9 to Registration
Statement No. 33-31731 of our opinion dated September 25, 2000 appearing in the
Prospectus, which is part of such Registration Statement, and to the reference
to us under the heading "How The Fund Works--Auditors" in such Prospectus.
DELOITTE & TOUCHE LLP
New York, N.Y.
October 18, 2000
