Dr. E. B. Chain
Istituto Superiore di Santta
Viale Regina Margherita, 299

Roma, Italy.

Dear Dr. Chain:

I have not had an occasion, as yet , to thank you in person for
your invitation to contribute to the Symposium on chemtherapy. I hope
the detulled and roundwbout iavestigations will not have embarrassed yoy;
they wers, I supposs, Inevitable in view of theme- the participation of
four people at widely separated places. However, the main reason for
delay must rest on me: I was away from campus for a good part of January
and rebruary, and was unable to devote myself to my part of the ms.
until some brief time after my return. Meanwhile, Dr. Cavalli has speek
spoken with full authority for both of us, and I asaume £6 will help to min#-
mize any further confusion if we continue this arrangement. I hasten
to add that the adjunction of Dr, Cavalli to this venture has been absolutely
indispensable, and that whatever merit comes from it will be a result of
the collaboration. I am indeed pleased that your assent craated the occasion
for a continuance of our cooperation.

IT have just been able to forward my immediate part of the ms. to Cavalli,
and hope that I will have left him enough time to fulfill his commitment to
you. As this 1s in a sense a double paper, I hope you can give him double
consideration in providing time for its completicn.

Yours cordially,

Joshua Lederberg

Associate Professor cof Genetics