Graph showing the status of the seminiferous epithelium (most advanced germ cell type) as percentage of all tubular structures in the grafts. 8I, Intact recipients with eight newborn hamster testis grafts; 8HC, hemicastrated recipients with eight newborn hamster testis grafts; 8C, castrated recipients with eight newborn hamster testis grafts; 2I, intact recipients with two newborn hamster testis grafts; 2HC, hemicastrated recipients with two newborn hamster testis grafts; and 2C, castrated recipients with two newborn hamster testis grafts; Ghosts, remnant of a seminiferous tubule containing no seminiferious epithelium; SCO, Sertoli cell only; SG, spermatogonia; PL/Z, preleptotene/zygotene spermatocytes; RS, rounds spermatids; ES, elongated spermatids.