April 25, 1952

Dear Dr. Boulgakov:

Thank you very mich for the reprints which were received
some time ago, an@ for the package of bacterial and bacteriophage
cultures received just yesterday.

I am writing simply to acknowledge that these have arrived
in good condition. In preliminary tests, however, the phage
samples marked " Sertic-Boulgakov 1936" did not behave as expected:
this phage lysed both the 0-901 and OH-901 S. typhi (Felix), and
gave strong lysis. The other samples, marked VIII-113 passage
strain 372, appear to be specific for the OH-901, and presumably
correspond to the published description of the faagellotropic
phage. Would you suggest that this discrepancy is worth investi-
gating?, or should we simply discard the "1936" sample?

Dr. B. A. D. Stocker, who I understand has also written to you
about flagellar phages, will be coming to this laboratory in a few
weeks, and I expect we shall be working togéther on them. We shall
communicate any interesting developments.

May I express my sincere appreciation for your kindness in
sending this gaterial.

Yours truly,

Joshua Lederberg
Associate Professor of Genetics