(Marine Biol Lab
Woods Hole, Mass)

August 8, 1954

Dr. 38. T. Cowan

National Collection of Type Cultures
Central Public Health Laboratory
Colindale Avenue,

London NW 9, England

Dear Dr. Cowan:

Thank you for your letter ef July 14 on the E. cold nos.
122 and 123. I am sorry to learn of the obscurity of thelr origin,
but am obligated to your for your trouble and interest.

Yours sincerely,

Joshua Lederberg
Professor of Genetics