Aprll 23, 1958

Mr. John Pfaiffer
PLO. Box 197
New Honea, Pennsylvania

pear kre, Poeiffer:

Tusa st sy ning pgople you #lil want to see it is hard to draw
the line. ‘thile yon are in Naples you ought to meet Paul Buchner (see
enclose) “t tha Museo dell’ Iscla d'Isehia, Porto d'Ischis. In Pavia
there Js Cavalli at the denetics Departasnt (right now he is with ms in
Madison but ne #1il return in July); there 49 also Buz-atti-Travesgo who
ds an sccomclisned tvolutionist.

You will already know ebout the Pusteur Institute group in Paris;
you should also met Tphrussi and L'Meritier at the CNRS lab at Gif-sur-
Ivette uxl Teissier at the sorbunne, Toll be in Purls «yuelf (for a
moeting at Royauuont) the last week in July. The microbiology congress
at Stockhola August 4-9 aight interest you. In the U. K. the Ay] character
is of course Crick at Cambridge; he will be away most of the summer after
mid June. You can't afford to mise hin though you might meet him during
your travels. There are a lot of labs in London ~ you aight especially
want to meet Pollock at Mill Hill ani Medawar at University College. Pirie
at Rothamsted is one of the scutest commentators on the origin of life.
Other important evolutionists are Huxley (Julian, T. M.'s grandson);
Danielii, at Kinga College, London; R. a. Fisher (inquire at Cambridge);
Waddington at Edinburgh. You my want to meet the group at Harwell work-
ing on artificial mouse-rat chimaeras.

There is no point enumerating all the biologists in Furope. Paris
and London are obviously the most active centers.

I'm not the man to say much on the astronomical side. You want to
try to catch Hoyle & Co. at Cambridge. Van de Hulst (Leiden) is a world
authority on interstellar matter. I was mich impressed by Dufay's book -
he ia I believe at the Lyon observatory. If there is another astrophysical
collaquium at Liege this summer you'll want to catch it. « biochemical
evolutionist Florkin is also at Liege.

Of course the most active group of theorists on biochemical evolution
has been the dussians ami if you have a chance you ought to include Moscow
(Academician Oparin) in your itinerary.

This should be more than you can possibly manage. If I don't see you
in Europe then perhaps back here in the fall. I am planning to be abroad
(Parise—Stockholm-London-Edinburgh-Montreal) for a circuit of meetings and
Congresses from about July 25 to the end of august.

Best wishes,

Joahua Lederber,
JL, /ew Pyofessor of Medical Usnetics