Merch 21, 1961

Or. Richard $. Caldecott
Geneticist, Blology Branch
Division of Blology and Medicine
U. S. Atomic Energy Commission
Washington 25, D.C.

REF: BMB: RSC
Dear Doctor Caldecott:

Thank you for referring GK narcovic's station to me for comment.

Dr. Marcovich {s well known as a careful and productive worker In the
radloblology of bacterla. His experimental designs are well calculated to
give fundamental! Information on the mechanism of lethal actlon of radiation-
Information which Is very badly needed both as a problem in basic sclence
and In the assessment of the biological damage Induced by radiations. He
Is credited with perhaps the most useful work In the blological measurement
of the effect of very low doses of radiation in favorable material. if
any Justification Is needed for support of work of this kind in another
country, it should be on the basis of the unique confidence of the Inves-
tigator In a research area of critical Importance. 1! do not know of any
quite comparable Investigations being carried out In this country - If they
are, they must be besed directly on the recent prior work by Marcovich
and Latarjet.

Zé

OL I7ACIA AL

f-/

Yours sincerely, .

Joshua Lederberg
Professor of Genetics

P.S. May | note an error In transcription In your letter - Dr. Trefouel
ts the director of the Pasteur Institute.