YALE UNIVERSITY SCHOOL OF MEDICINE 333 CEDAR STREET ‘ NEW HAVEN - CONNECTICUT DEPARTMENT OF PHYSIOLOGICAL CHEMISTRY STERLING HALL OF MEDICINE May 29, 1952 Dr. Joshua Lederberg Department of Genetics College of Agriculture University of Wisconsin Madison 6, Wisconsin Dear Josh: Thanks for the cultures and the reprint. Both arrived in good condition. As was to be expected, two days after I sent the reprint request, Dave gave me the copy you'd left. With best regards to Esther, Yours sincerely, RY Sofia S onds SS mb