BOARD OF TRUSTEES EXECUTIVE COMMITTEE

CARL LAMANNA, R. E. BUCHANAN CARL LAMANNA, CHAIRMAN
SOCIETY OF AMERICAN BACTERIOLOGISTS R. E. BUCHANAN
HK. HM. MCKINNEY
H. H. MCKINNEY

AMERICAN PHYTOPATHOLOGICAL SOCIETY

a scouta AMERICAN TYPE CULTURE COLLECTION
AMERICAN ASSOCIATION OF 2029 M STREET. N. W. CURATOR
PATHOLOGISTS AND BACTERIOLOGISTS WASHINGTON 6. D. C. FREEMAN A. WEISS

WR. P. HALL

AMERICAN SOCIETY OF ZOOLOGISTS AESISTANT CURATOR

R. W. DAVIDSON R. LLOYD PHILLIPS
MYCOLOGICAL SOCIETY OF AMERICA
NR. SMITH TES BOEDIN, Bacreniovosisr
AMERICAN INSTITUTE OF BIOLOGICAL SCIENCES . ,
R. D. COGHILL, G. W. IRVING, JR. SECRETARY-MANAGER
NATIONAL RESEARCH COUNCIL KATHERINE ALVORD

May 15, 1953

Dr. Joshua Lederberg
Department of Genetics
University of Wisconsin
Madison, Wisconsin

Dear Doctor lederberg:

We have a request for a uracil-requiring mutant of B. coli
#550-460, but heve been unable to find a reference to a strain
bearing this number, On the chance that it may be one of your
strains of B. coli I am writing to inquire. In case you heave it
we would like to receive a culture. If you don't, please write

*no* on this letter and return.

In any event, thanks,

Sincerely,

Freeman A. Weiss
Curator

FAaW/ap