ON SOMATIC SEX-CHARACTERS 105 



He claims by transplantation of the gonads in young 

 rats and guinea-pigs to have feminised males and 

 masculised females. The females are smaller, and 

 have finer, softer hair than the males. The testes 

 were removed and ovaries implanted in young males. 

 The animals so treated grew less than the merely 

 castrated specimens, and therefore when full-grown 

 resembled females in size. In the young state both 

 sexes have fine, soft hair, the feminised males had the 

 same character, like the normal females. They also 

 developed teats and milk glands like the females, 

 and were sought and treated as females by the normal 

 males. When the implanted ovaries are able to 

 resist the influence of their new surroundings, the 

 female interstitial gland, which Steinach calls the 

 puberty gland, develops so much that an intensifica- 

 tion of the female character takes place : the animals 

 are smaller than normal females, the milk glands 

 develop and secrete milk, which can be easily 

 pressed out, and if young are given to them they 

 suckle them and show all the maternal instincts. 



Why the ovary in normal circumstances only 

 when in the gravid condition calls forth this per- 

 fection of f emaleness is to be shown in a later publica- 

 tion. By acting with Rontgen rays on the region 

 where the ovaries lie, Steinach and his colleague 

 Holzknecht brought about all the symptoms of 

 pregnancy, development of teats and milk glands, 

 secretion of milk, and great growth of the uterus in 

 all its layers. 



Masculising of females was much more difficult 

 than feminising of males because the testicular tissue 

 was less resistent, and could not be grafted so easily. 

 When it succeeded, however, degeneration of the 



