NATIONAL COLLECTION OF TYPE CULTURES (MEDICAL RESEARCH COUNCIL) CENTRAL PUBLIC HEALTH LABORATORY, Telephone : COLINDALE COLINDALE AVENUE 6041 and 4081. LONDON, N.W.9 14th July, 1954 Dear Dr. Lederberg, Dr. Felix tells me that you have been inquirying for details of the origin of NCTC nos. 122 and 123. Unfortunately our information is very meagre and all we know is that both strains were in the original collection taken over by my predecessor from the Lister Institute in January, 1920. The strain names of the cultures suggest that their origins were quite distinct; 122 is named Hueppe and 123 St. Georges, St. Georges being the name of a hospital in London. All those likely to have handled the cultures when they were first received at the Lister Institute are dead and I do not think we shall be able to trace their origin with any degree of certainty. Yours sincerely, L -T. Cowan, Curator. Prof. J. Lederberg, Department of Genetics, University of Wisconsin, Madison 6, Wisconsin, U.S.A.