AMHERST COLLEGE
Amberst, Massachusetts

DEPARTMENT OF BIOLOGY

January 22, 1948

Dr. Joshua Lederberg

Assistant Professor of Genetics
The University of Wisconsin
College of Agriculture

Madison 6, Wisconsin

Dear Dr. Lederberg:

I had your note, and I will send the glucose-
negative strain of Salmonella shortly. I prefer
to wait a little while longer, however, since

we are still trying to clear up the exact condi~
tions under which this strain does not utilize
sugar. It seems to have some relation to the
character of the salts furnished in basal
medium.

In any case, we appear to be involved in the
oxidation-reduction mechanism of this organism.
We are still mach concerned also about dextrose
and glycerine positive strains which show
specific inhibitions with one or another of the
amino acids. I will see that some of these
are sent to you, also,

With kindest regards,

Sincerely yours,

dS lucy

H. H. Plough
Professor of Biology