[Masculinization of prepubertal and pubertal females of Sphaeroma serratum Fabr., (Crustacea Isopoda Flabellifera) by implantation of an androgenic gland of pubertal male].

In Sphaeroma serratum, the differentiation of the male external sexual characteristics, as a result of an androgenic gland implant, proceeds more easily in females in vitellogenesis than in immature females. On the contrary, the transformation of the gonads is quicker and more obvious in immature females than in mature ones. This transformation which leads, in all cases, to an inversion of the ovary to a functional testicle able to produce spermatozoa, always occurs without any differentiation of an androgenic gland, contrary to what can be observed with Oniscoïds. The details of the external sexual differentiation of the grafted females can be related to the functioning of a protocerebral neurosecretory center having, as in males, an androinhibitory effect on the androgenic gland implant; the activity of this center, which seems to correspond to the center secreting VIH, would be particularly high with immature females and would become very low--or nonexistent--in females in vitellogenesis.