September 29, 1959

Dr. Joshua Lederberg
Department of Genetics
Medical School
Stanford University
Stanford, California

Dear Joshua and Esther:

In working up the order of the Gal mutants I have

gotton to G and Galg and this has presented me with a problem.

According to Esther's abstract of the Genetics Congress; 1958

these two mtants are cistronic with both the 2,8 and 1,4,6,7 groups.

Precisely what was the experimental evidence here? I have W3109

(original stock from EMI.) and 72236 and don't believe that heterogenotes

between these stocks and Gal,~ have a negative phemtype. Some of

the heterogenotes between W3i09, W2236 and 1,h,6,7 may show positive

effect, but I don't believe all combinations will. In this connection

you had best advise me of genotypes of heterogenotes studied Bf you
and

and_you might also send me "certified" stocks of Gal3 (W3103?
Galo.

Difco is considering putting out the indicator agar that
I devised and has made some experimental lots, I believe that
they will send samples for trial to people that I suggest. Would
you like a batch for trial?

I haven't yet been able to pick a date for a trip to
visit you. Classes are just starting for Helvise and Margaret
and in a couple of weeks things will settle down.

AS ever,

M. L. Morse, Ph.D.