Sterilization by Cryosurgery: A Report of Animal Fertility Studies*,*Supported by grants from the Rockefeller Foundation and from the United States Agency for International Development.†,†Performed in collaboration with the Reproductive Physiology Laboratories of the Division of Animal Sciences, North Carolina State College at Raleigh, North Carolina.‡‡Reprint requests, J. F. Hulka, M.D., Room 402A, School of Public Health, University of North Carolina at Chapel Hill, North Carolina 27514.