September 253 1954

Dr. Werner Braun

NB Division, Cml C Biol Labd.
Camp Yetrick

Frederick, Md,

Dear Werner:

Thank you for your letter of September 23. I have already written
to Devignat, as you see from the enclosed copy. It might help if you
reinforced my lettar with your own message to indicate your interest,
as I suspect a certain shyness or formality on his part.

I am glad to hear of your return (at least in part) to the academic
world, That will you use for a textbook? All joking aside, I am astonished
at your willingness to accept such a large enrolment; {£n your place, I
would have set such standards as would be necessary to ksep it tbthin
reasonable limita. I am sorry we will not see you this December, but
there are bound t be many other opportunities.

Esther will write you soon about the heterogeneous "pretotrophs".
The mein consideration probably was that most of the isolates had
carried along auxctropha (probably mostly from the heavy parental
seeding; possibly some other recombinant auxotrophs alsc), Under
certain conditions, auxotrophs succeed astonishinglybwell in main-
taining their numbers at a small proportion of progotrophic celks
dn colonies oa synthetic medium.

We are just now beginning to run out of reprints of our lysogenicity
paper, in spite of having forwarded many of the requests to you. If the
supply at CampPetrick is still sufficient, would it be possible for us

to get = few dozen more from you? If necessary, we can repurchase them
from other funds.

Yours sincerely,

Joshua Lederberg