UNIVERSITY OF CAMBRIDGE DEPARTMENT OF PHYSICS

M.R.C. Unit
TELEPHONE CAVENDISH LABORATORY
Campripce 54481 FREE SCHOOL LANE
CAMBRIDGE

1 April 1958

Dear Josh,

I don't think you can turn the bases over easily,
with the exception of adenine. They tend to foul the sugar
if you do. Of course it can happen occasionally, but it
must be a rare event. I don't understand your sentence
about "above or below" the Ci of the deoxyribose. I should
have to see a model.

As to the summer, I shall be around the East Coast
(for a Gorden Conference) from about mid June till early
July, then back to Cambridge. After that the phage meeting
in France and in early September the International Bio-
chemical Congress in Vienna. It would be very nice to see
you and Esther here, but in any case we shall meet at
Royaumont. oe

We have proteins without genes and genes without
proteins, but hopes are high, and everybody is working like
mad, except Seymour who is on holiday. 7

Give my love to Esther,
Yours ever,
— ‘
flaws —

F.H.C. Crick

Professor J. Lederberg,
Department of Genetics,
University of Wisconsin,
Madison 6, Wisconsin,
U.S.A.