DEPARTMENT OF BACTERIOLOGY AND IMMUNOLOGY HARVARD MEDICAL SCHOOL 28 SHATTUCK STREET BOSTON 15, MASSACHUSETTS March 25, 1958 Dr. Joshua Lederberg Genetics Building The University of Wisconsin Madison, Wisconsin Dear Joshua: I am very grateful for the copy of your manuscript which you so kindly sent me of your paper with Nossal. I think it is an elegant piece of work, See you next week. Sincerely yours, Chb.T Albert H. Coons