INDIANA UNIVERSITY
BLOOMINGTON, INDIANA

DEPARTMENT OF BACTERIOLOGY

December 12, 19:7

Doctor J. Lederberg
Depertment of Genetics
University of Wisconsin
Madison, Wisconsin

Dear Lederberg:

I have not answered your letter earlier because I hoped I
could soon take up the ma*ter you mentioned. It is clear, how-
ever, that I will simply not have time to study the mutational
pattern of your bacterial strain for quite a times On the
other hand, I would hasitate very mich to decide what are
simple and what are complex mtants without a thorough study
of the mutational pattern, particularly without a study of the
presence in the complex mutants of exactly the same correlated
characters as in the simple mutantse This would require lots
of work and careful analysis. Maybe after January I may be
able to get around to doing something along these lines. I
would suggest that if you isolate large numbers of mutant
resistents tc different phages and compare their range of
sensitiveness, vou may hit rather easily on some complex
mutants «

I am looking forward to sseinr you in Chicago.

Best regards,
rr a

S. B. Luria

SEL:pr