December 20, 1954

Dear Dr. Garven:

I will be happy to send you the reprints you asked for.

You should write to Dr. Evelyn WitHin, Biolagical Labs. ,

Cold Spring Harbor, LI.,N.Y¥. concerning the Microbial Genetics
Bulletin.

I am happy to learn of your interest in EF. coli genetics. If
you have occasion to visit Melbourne, you may find it congenial and
profitable to talk with Professor Rubbo, who spent a few months

here last spring, and who is expanding an intresting program of
teaching and research.

I don't know precisely what you had in mind by way of studies
on "pathogenin" EB. coli, but you probably will be interested to know
that Dr, Aleck Bernstein (on leave from the PHLS, Gt.Brit.) has been
spending the pastsand will be here anothersyear to work on recombination
in "055, Olll, 026 etc." strains. Only a very few of them have proved
to be fertile, and Dr. Bernstein is in the midst of preparing avuxo-
trophic mutants in then now, the better to proceed with intercrossing
experiments. xmxduustema immediate objective is to clarify their
immunogenetics, e.g. to learn whether the O ahd B factors are separable.
There does not seem to be any practicable way to examine their patho-
genicity, for lack of suitable experimental animals, and we had no hopes,
therefore,of going into this aspect of it. Please let us know if we can

give you any more detailed information that would be helpful to the
planningof your own program.

Aith best wishes of the season,

Joshua Lederberg
Professor of Genetics

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