Basis of Sex Determination 227 



secondary sexual male characters. On the contrary, 

 Steinach was able to show that the growth of the 

 penis was directly inhibited by the ovary, since in the 

 feminized males this organ remained smaller than in 

 the merely castrated animals. On the other hand the 

 infantile uterus and tube when transplanted into the 

 young male with the ovaries grow in a normal way, 

 and Steinach thinks that pregnancy in such feminized 

 males is possible if sperm be injected into the uterus. 

 In some regards the feminized males showed the mor- 

 phological habitus of females. Soon after the trans- 

 plantation of ovaries into a castrated male the nipples 

 of its mammary glands begin to grow to the large size 

 which they have in the female and by which the two 

 sexes can easily be discriminated. In addition the 

 stronger longitudinal growth of the body in the male 

 does not occur in the feminized specimens, the body 

 growth becomes that of a female; and likewise the fat 

 and hair of the feminized male resemble that of a real 

 female. 



While the castrated males show an interest in the 

 females, the feminized males are absolutely indifferent 

 to females and behave like them when put together 

 with normal males ; and, what is more interesting, they 

 are treated by normal males like normal females. The 

 sexual instincts have, therefore, also been reversed 

 in the feminized males by the substitution of ovaries 

 for testes. 



