February 20, 1961

Dr. FP. R. Edwards

Department of Health, Education and Welfare
Public Health Service

Communicable Disease Center

Attenta 22, Georgla

Dear Phi}:

| hardly know better than you what to make of your 3 phase types.
They may be related to the odd ball CDC-137 which proved to be Hy: H,'2
(sic). When you succeed in getting transductions In these stocks you
can at least explore what the homologous replacements are. For example,
| would try say:

S. grumpensis 4:1,7 x Zia: Iw Z

if you get d ——> Iw <—> or more Vikely 1,7: —>lwe—> 7 you can at least
be sure that 2). —> Iw Is not merely a mutation like Hy? —> H,*33. Too
bad you don't have some similar cdd balls In group B.

Bruce Stocker Is visiting us again (till June), but we have very
little Salmonella going on right now. Instead we are trying to work up
Bacillus subtilis along similar tines (flagetier and antigen mutants).

 

Good tuck,

As ever,

Joshua Lederberg
Professor of Genetics

Enc. Nester & Lederberg