TELEPHONE PADoincton 1662 THE WRIGHT-FLEMING INSTITUTE OF MICROBIOLOGY,
ST. MARY’S HOSPITAL MEDICAL SCHOOL,
PADDINGTON, LONDON, W.2.

20th June, 1956.

Professor J. Lederberg,
Department of Genetics,
University of Wisconsin,
Madison 6,

Wisconsin,

U.S.A.

Dear Dr. Lederberg,

Thank you for your letter about the
penicillin sensitive mutants of E. coli. I am
very much afraid that we no longer have these
cultures. We ourselves lost interest in them
and nobody else seemed to want them.

Yes, I was sorry not to be able to
call on you on my recent trip to the U.S. I
would like to see Tom Nelson again and also,
of course, to meet you. I hope to be over
again next year, so perhaps we will remedy the
omission then.

Sorry that I cannot be of any help.

Yours sincerely,

Derrick Rowley.