THE UNIVERSITY OF CHICAGO
CHICAGO 37° ILLINOIS

INSTITUTE OF RADIOBIOLOGY AND BIOPHYSICS

1155 Bast 57th Street
Chicago 37, Illinois
December le, 1951

Dr. Joshua Lederbérg
Department of Genetics
Univer sity of Wisconsin
Madison, Wisconsin

Dear Lederburg,

I am writing to say that both Novick and I were very much
pleased with Zinder's visit. After we had talked to him for two days, we asked
a few people to came over and listen to him giving a seminar, We wanted just a
few people but apparently word gets around on the Campus and Zinder spoke before
a distinguished audience which filled the seminar room, His talk was very good
both in substance and in delivery, and the people were quite impressed with his
maturity.

I looked through the draft of Zinder's manuscript which I
understand he has not yet shown to you, It seems to me that it contains the
nucleus of an historically very important paper, and because this is so, it
might be wrth while to give same thought to its organization and also to the
place where it may be published. I believe tmt if the paper is properly or-
ganized and all extraneous matter left out of it, such as references to the
possible connection of the phenomena with L-forms, for which I could not see any
real evidence presented, the paper could be quite short and lucid, amd if it
were short and lucid you might consider having it submitted to the Proceedings

of the National Academy of Sciences where it would have a much broader audience

than in any of the more specialized journals.
Dr. Joshua Lederbérg -2- | December 12, 1951

As to organization of the paper, it seems to me that if the
paper started out by telling the story of the discovery; i.e. by explaining what
was attempted, and how the "contraceptive experimmt" gave a startling result, and
if this were then followed by clearly setting out what the subsequent experiments

in the author's opinion have established, it would then be much easier to under-
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stand the individual experimmts that are described and ie sonia @ (of which
are consistent with the conclusions presented at the outset of the paper. The
presentation of tna/ paper is, of cowse, entirely a matter of individual taste
but I find that unless I know in advance what the author thinks he has proven or
made plausible, I have to read the pa~er twice instead of only once, for until I
know what the author thinks he has proven it is not possible to read with the proper
critical attitude the individual experiments which are listed in support of the
author's contention,

As to the substance of the matter, what I would be most eager
to know is the following: Could it be that the transducing agent, which is of
course of bacterial origin, is somehow incorporated in a phage particle which is ative
from the donor bacterium, and tmt this phage particle acts as a vehicle of trans-
mission? This would of course mean tmt the phage released by the donor strain
must in all cases be absorbed by the strain which is transduced even though this
phage need not grow in the strain which is transduced. Zinder tells me that typhi
which is transduced is not susceptible to the phage of the donor strain, but the
question still remains whether it absorbs the donor strain.

One of the reasons why this question appears to me as having some
urgency is the sad fact that if indeed the phage should act as a vehicle of trans-
mission, thn further investigation of FA will necessarily remain a much more re~

stricted field than it would be otherwise. So for setting out a general plan for
Dr. Joshua Lederb&g -3- December 12, 1951

the investigation of this field, the question which I am raising here is a rather

a?
crucial one // 1 told Zinder that we would like to have him in Chicago and that we
Le
shall see what we can do about this, awd that he should in the meantime not neglect
aust

other opportunities which he may have, mt just keep us informed of how his plans
develop and what opportunities he thinks he may have elsewhere.

I had a letter from Mr. Pomerat of the Rockefeller Foundation
about the Klieneberger-Nobel plans for a visit to America, I assume that he wrote
you also but if not I shall forward you his letter after it has been answered,

With kind regards,

Sincerely yours,
4 7 “ ;
a wo ae
Leo Szilard