556 SWALE VINCENT 



transplanted 'tissue, followed by atrophy of the uterus. The rate of 

 degeneration varies with the site of implantation; the more vascular the 

 site, the longer the persistence of the graft. Degeneration takes place first 

 in the cells of the corpus luteum, as evidenced by hyaline changes and 

 leucocyte infiltration. The follicles show cystic degeneration. The in- 

 terstitial cells persist much longer than the follicles, and they appear 

 to control the nutrition of the uterus, as atrophy takes place when these 

 cells are degenerated, and no atrophy when they are present without any 

 trace of follicles. These experiments were carried out on rabbits and 

 guinea pigs. The longest experiments were not continued more than two 

 hundred days. Marshall and Jolly, as we have seen, found a transplanted 

 ovary normal after fourteen months. 



Transplantation experiments have been utilized for the study of the 

 relation between ovary and mammary gland. It has been shown by 

 Steinach that, if ovaries are transplanted into young male guinea pigs, 

 the mammary gland develops and forms acini and may even secrete milk. 

 This author believes that the ovarian interstitial cells are responsible for 

 this effect. Athias has confirmed the results of Steinach, though he is not 

 so definite in his opinion as to which constituent of the ovary is responsible 

 for the changes observed. He believes, however, that it is not the corpus 

 luteum which is so responsible. 



An interesting paper by Lipschiitz (&) (1917) gives an account of 

 Steinach' s work and some further experiments of a like character, tending 

 to prove that the internal secretion of the sexual glands acts in a sex specific 

 manner, i. e., the male gonad furthers the development only of male 

 sex characters and inhibits the development of female sex characters, 

 whereas the female gonad furthers the development of female sex char- 

 acters and inhibits the development of male sex characters. From ex- 

 periments of Goodale (e) and Pezard (b) (c. ), Lipschiitz concludes that the 

 development in birds of the male plumage and the spurs does not depend on 

 stimulation by the male sexual gland, whereas the female sexual gland 

 transforms a male plumage into a female one and inhibits the growth of 

 the spurs. lie considers that the male plumage and the spurs are evolved 

 out of the characters of the hypothetical non-sexual embryonic form, 

 without any influence of the sexual glands. The male plumage and the 

 spurs become male sex characters, not because they result from an action 

 of the male sexual gland on the non-sexual soma, but because the de- 

 velopment of these non-sexual characters is influenced in the female by the 

 internal secretion of the female sexual gland. So that Lipschiitz groups 

 the sex characters of the vertebrata in the following manner : 



1. Sex characters not dependent on the "puberty gland" (Steinach) 

 or evolved characters of the non-sexual embryonic form. 



2. Sex characters dependent on the "puberty gland," which evokes 



