February 27, 1956

Dr. Herman Kalekar
National Institutes of Health
Bebhesda, Maryland

Dear Herman:

I am sorry that wo heave taken so long about developing the %. coli
Gai- outunts for you. However, Lt seemed 4mportant to reduce them as
far os posulble to u uniform genetic background, and this has taken a
few weeks of transductive “back-crossing". The straine are just abont
ready; it would be aimplest perhapa if I gave them over in person,

Vig expect to visit Maushington March 10-12, arriving Saturday aidaf-
ternoon. if possible, we would like to spend Saturday evening with you,
as this would be the pest tima to discuss the posathilities of handling
““s Goli and its autunts. If this is quite impossible for you, then we
might make a date for Sunday night. We will be staying at the Lafayette
Hotel, or can be reached Bla Vernon Bryson at the NSF, if you have to
communicate with us after’ wa leave Madison (Saturday AM).

Hank Lardy said you had some ideas about gametic selection. I would
be very interested tu discuss this with you too. I think most geneticists
have been unduly impressed by results from Drosophila: the equal trans-
mission of gamtes carrying very large chromosomal deficiencies has implied
to them that there is no genetic expression in the gametes themselves, that
they are determined entirely br the ertire diploid parent from which they
arise. Bat the fact thet the primary sex ratio in man deviates 30 markedly
from the meddelian retio is eneugh evidence for me that this conception
is lacomplete.

See you in a couple of weeks,
Sinc ekway,

4
+

Joshua Lederberg