Abstract
Heterotransplantation of human foetal testicular and ovarian tissue from five human foetuses was performed on a total of 9 mice of the nude mutant. the grafts were inoculated subcutaneously and were accepted by 3 mice with testicular tissue and 2 mice with ovarian tissue. After 4 to 8 weeks the grafts were removed and prepared for light microscopy. in the testicular tissue both undifferentiated Sertoli cells and gonocytes were shown in the seminiferous tubules, and the gonocytes were present in 73 to 90 per cent of the tubular sections. in the ovarian tissue the structure was preserved and a mixed population of oogonia and oocytes was found.