1. Department of Experimental Biology, Roswell Park Memorial Institute, Buffalo, New York, and the Department of Medicine (Medical Genetics Unit), State University of New York at Buffalo and Buffalo General Hospital.
2. Roswell Park Memorial Institute, Buffalo, N. Y.
3. State University of New York at Buffalo and Buffalo General Hospital; present address: Sunnybrook Hospital, Toronto, Ontario.
4. State University of New York at Buffalo and Buffalo General Hospital, Buffalo, N. Y.