September 19, 1952

Dr. M. Delbruck
Blology

Caltech

Pasadena 4 California

Dear Maxt

Thank you for the hectographed notea which have just arrived. Does
Dr. Vogt intend to publish her findings in the proximate future?

Some time ago, Weigle asked for a copy of the Sex Compatibility ms.
I was unable to send this to him at the time, as I had only oy own
single copy. The proof has just now been corrected, so that a copy is
available. A few minor corrections have since been made, and I seem to
recall that there may be a misplaced + for - somewhere in it, but hope
this will not be confusing. May I address this to you, as I am not certain
of Weigle's immediate whereabouts. Possibly he has had an opportunity to
discuss the work with Cavalli more directly.

Tom Nelson has just arrived to work here for a year, and we are planning
more precise quantitative experiments to cover some of the obvious weak
points mentioned in the ms. The results with Hfr have been very encouraging.
We have not yet seen mating, but have seen individual cells (of essentially
normal appearance) which were proved later to have been zygotes. Some answer
to the problem of the morphological basis of the mating should be available
I hope within the hext year or two.

Cavalli and we are
ration on this problem. sincerely ne our ccollabo~

Joshua Lederberg
_

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