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THE PUBLIC HEALTH RESEARCH [NSTITUTE
OF THE City OF NEw YorK, INC.

Foot OF EaAsT 15TH ST., NEW YORK 9, N. Y.

TEL. OREGON 7-4411

January 20, 1958

Dr. Joshua Lederberg
Professor of Medical Genetics
The University of Wisconsin
School of Medicine

Madison 6, Wisconsin

Dear Joshua:

Thank you very much for your invitation to the symposium, which
I am pleased to accept. Unfortunately, the animal virus genetic field is
not moving forward very rapidly and I shall have very little that is new
to contribute. We have some results with Newcastle Disease virus, which
fails to show recombination down to a fairly low level, but with influenza
I have been mainly concerned with getting the virus to behave well ina
plaque-forming system and I am determined to do this before trying any
more genetic experiments. I think it will work out but it is a very
delicate system.

I was very much surprised to find that you had familiarized
yourself with what I consider to be a very messy situation with respect
to influenza virus recombination. I agree with you completely as to the
probable explanation of the difference between our results and those of
Sir Mac on the Melbourne WS experiments. I should be much interested in
hearing any further details you may have about discussing phenotypic mixing
with Sir Mac. I have always felt that he was unconvinced that there was
such a phenomenon but he never discussed it directly with me.

I am enclosing the reprints which you requested.

I also want to take this opportunity to say how much I enjoyed
your recent Harvey lecture and I am looking forward to seeing you in
Madison in April.

With kind regards,

Sincerely yours,

Splendid M4
T*1l be glad to talk to you about it in April. “ a

i

Burnet may (or may not)be there too. He's leaving ~ \

in about a month for a semester atvVanderbilt,

les
irol,.

George K. Hirst

I think he is gradually straightening out
his interpretation of phenomixing, though
every now and then there is some allusion
to recombination or heterozygosis in a contaxt that
surprises me, But he has many references to anomalous
neutralization, e.g., in the 1953 CSH and in papers in the Australiam J....
= his book (p. 418) he gratuitously adds "and, in all probability, carry
wo or more sets of genetic determinants. He just thinks so: I've tried to argue
@ point, J

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