The Relation of the Scrotum to Germ Cell Differentiation in Gonad Grafts in the Guinea Pig

Abstract

Testes transplanted from one guinea pig to another persist for months. In subcutaneous or intraperitoneal grafts only slight indications of spermatogenesis are found, whereas grafts made by transplanting the testes onto the walls of the empty scrotal pouch have been recovered 5 1/2 months after transplantation in an active and completed spermatogenesis; seminiferous tubules showing all stages of spermatogenesis and metamorphosed spermatozoa proves that differentiation continues and is initiated after transplantation since these transplanted testes were obtained from animals long before the onset of sperm production. The scrotum is a local thermoregulator, perceptibly reducing the temperature of the abdomen, and in the scrotal environment germ cell production continues in successful testis transplantation. Data at hand indicate that ovaries, normally subjected to the higher abdominal temperatures, are not hindered in their activity by the reduced scrotal temperatures. Ovarian grafts removed from the scrotum some months after transplantation were in essentially the same state as subcutaneous grafts; follicular development continues as follicles of all stages of development were present.