YALE UNIVERSITY
OSBORN BOTANICAL LABORATORY
NEW HAVEN, CONNECTICUT

June 18, 1948

Professor Joshua S. Lederberg
Department of Genetics
College of Agriculture
University of Wisconsin
Madison 6, Wisconsin

Dear Josh:

Thanks for your letter of June 5th. I was interested
to learn of your Salmonella mutant which requires isoleucine and valine.
You might send it to me since it might work into the general problem
of this interrelationship.

Regarding exchanging cultures: I suspect in the long
run it would be best for you to form your own collection of cultures,
{ should very much appreciate knowing of my interesting strains that
you may turn up. Until such time as you have lyophilizing apparatus,
I shall be glad to have your strains lyophilized and stored here, to
be sent on to you when you are in a position to mintain your own
apparatus, There may be a slack period of about a month this summer
when we will be doing very little lyophilizing since I have not as yet
hired a person to care for the stocks and keep cultures lyophilized.
I-should be able to lmndle a batch sometime in August.

Hegarding the course in gmetics and microorganisms,
we haven't drawn up detailed outlines of the legtures as yet. I suspect
your lecture period would fit in best late in Senesmber or early in
November. We have many people in mind for the lectures. Those who have
agreed to come at the present time are: Sonneborn, Luria, Stackman,
Weston, and others I have undoubtedly forgaten. We have in mind getting
Hershey and Horowitz but arrangements concerning them are not fiml.
Winge has been invited but again we have not yet heard from him as to
whether he would be willing to come.

Sirerely,

/ Best regards to you and your wife,

N

a ine

David Bonrer
{ ‘hey Associate Professor of Microbiology

4L4 han,