The Jane Coffin Childs Memorial Fund for Medical Research 333 Cedar Street - New Haven 11 - Connecticut - October 9, 1952 Dr. J. Lederberg Department of Genetics University of Wisconsin Madison, Wisconsin Dear Doctor Lederberg: Thank you for sending us fifteen copies of the following article, which acknowledges aid from this Fund: Lederberg, J., Lederberg, E. M., Zinder, N. D., and Lively, E. R. Recombination analysis of bacterial heredity. Cold Spring Harbor Symposia on Quantitative Biology, 1951, 16, 413-443. Sincerely yours, Lh Guatece ‘Elfzabeth M. Mester Secretary