A Qualitative Indicator for the Testis Hormone. ∗

Abstract

Lack of progress in the study of the organs of internal secretion has often been due to the fact that sufficiently dependable, easily read indicators for the products of their activity, were not available. In the mammals this is especially true of the gonads, for these can be removed without causing death of the animals or exceptionally striking changes. In time, of course, certain changes occur that are of importance; in the male there is a diminution in size of the prostate, penis, and seminal vesicles when present, and in the female the reproductive tract undergoes retrogression. The psyche of copulation is often independable, for with the guinea pig I have noted males vigorously inclined to the female despite the fact they were castrated months before, and at an age of thirty days. It has likewise been reported that eunuchs, castrated at an early age, retain for years a persistent inclination to, and a degree of satisfaction in, the association with the female.

The work of Stockard and Papanicolaou 1 on the guinea pig, Long and Evans, 2 Allen, 3 and others on the mouse and rat has developed a dependable method for indicating the female hormone by using the vaginal smear as an indicator. The activity cycle of the female rat shown by the work of Wang, Wang, Richter, and Guttmacher 4 likewise gives promise as a dependable test for the female hormone. On the male side, however, the only promising qualitative test that can be relatively quickly applied to mammals is that of the “Activity” record developed along lines as indicated 4 which has been recently applied by Hoskins. 5 How safe an indicator this will finally prove to be is yet to be demonstrated.