INDIANA UNIVERSITY

BLOOMINGTON, INDIANA

DEPARTMENT OF ZOOLOGY August 30, 1946

Mr, Joshua Lederberg
Osborn Botanical Laboratory
Yale University

New Haven, Conn.

Dear Mr. Lederberg:

I was very glad to receive your interesting letter and to hear about
the new evidence for,sexual phase in E. Coli. I should certainly appreciate
having a note from you once in a while keeping me up to date on your latest
discoveries.

Do you remember the arrangement I mde with Dr. Dienes at C.S.H.? He
promised to send me his data so that I ry to find out whether the
"mating types" in his bacteria follow a breeding system comparable to any
other system known in lower organisms, I sent him a reminder after I re-
turned to Bloomington but have heard nothing further from him. Do you know
whether anyone has seen his data?

The questions you raise about the differentiation of mting types
in Paramecium bursaria is easy to answer. I,have seen no paper on this
since Jennings' paper of 1942. There is, of course, a superficial resem-
blance to the problem of phase variation,as Kimball suggests. How deep
the analogy goes, however, I cannot even guess because I lack the detailed
knowledge of the situation in bacteria on which to base a sound judgment.

So far as the serological aspects of mting types are concerned, you
now have at Yale a man who knows as much about thjs as anyone, and I strongly
urge you to get in touch with him. This is Dr. C, B. Metz who spent last |
year here as a National Research Fellow and who is starting in now as an
Instructor in the Osborn Zoological Laboratory. I think you will find he
has some very interesting things to tell you.

Cordially yours,

Witéve—rfo——

T. M Sonnebom