THE UNIVERSITY OF WESTERN ONTARIO FACULTY OF MEDICINE 375 SOUTH STREET, LONDON, GANADA DEPARTMENT OF BACTERIOLOGY AND IMMUNOLOGY THE HAMILTON KING MEEK MEMORIAL LABORATORY April 18th, 1952 Dr. Joshua Lederberg Department of Genetics University of Wisconsin Madison, Wis. Dear Lederberg: I enclose reprints of the work that we did on Micrococcus antibiotics. We have not done any further work on them and these papers summarize most of what we have observed. It is rather sketchy; the usual situation when deal- ing with unstable products or with products in- soluble in anything but water. Some of the characteristics resemble active materials from coliforms studied by the Oxford "group" but I do not think that we could relate then. We look forward to seeing you at Boston. Yours sincerely RM:ns R. GE. MURRAY, M.D. Professor