290 



INTERNAL SECRETIONS 



shorter and narrower than that of an ordinary "castrate." 

 But having examined in the last three years a great many 

 castrated guinea pigs, I now see that the proportions of the 

 penis after castration depend on the age at which castration 

 was performed (Bormann, 1922); there is also great individual 

 variation. So I am now rather inclined to the view that the 

 question of an inhibitory action of the ovary in the mammal 

 is not yet definitely settled, although such an action is more 

 than probable. 



Fig. 114. — Influence of ovarian transplantation on the teats of the castrated maU 

 guinea pig. — Photo of Steinach. 

 A. Normal male. 



Steinach implanted in one case into a castrated male, to- 

 gether with the ovaries, the uterus and the tubes ; the latter 

 developed. Rudimentary organs of the male, such as the teats 

 and the mammary glands, develop in the male organism under 

 the influence of the implanted ovary, and become finally like 

 those of a normal female {Fig. 114 A, B). In the first weeks after 

 birth there is no difference between the teat of the male and 

 that of a female guinea pig. The teats and the mammary 

 glands begin to grow in the female at about the age of two 



