INFLUENCE OF OVARIAN EXTRACT UPON THE SEX DIFFERENTIATION OF TERMINAL CREST IN THE TESTIS OF TRITURUS PYRRHOGASTER (BOIE)

Abstract

Crude extract of ovaries of Triturus pyrrhogaster was implanted into the testis of the adult male and observations were made on the histological differentiation of terminal crest at the apex of the testis. In the control animal pellets of a mixture of crystalline estrogenic substance and starch were grafted into the testis in a similar way as in the 1st group.
The implantation of ovarian extract brought about a striking suppression of development of seminal tubules in the terminal crest followed by the differentiation of oviform germ cells. These feminized germ cells appeared outside the seminal tubules and each of them was individually enveloped within the follicle cells derived from the walls of the seminal tubules. The modification of sex differentiation was observed not only in the terminal crests of the operated lobes but also in those which lie far from the site of implantation.
Crystalline sex hormone, on the other hand, exerted a severe destructive influence upon the germ cell differentiation in the testis but the differentiation of primordial seminal tubules was less conspicuously affected and oviform germ cell differentiation was detected only in a single specimen in which 2 cells accompanied by several small spermatogonia were formed in a common follicular tissue derived from the cells of the wall of seminal tubules.
These results, taken together with those of previous experiments, show that the ovary of T. pyrrhogaster produces an inductive substance which affects the sex differentiation of the terminal crest in a manner different from that of estrogenic hormones already known.