80 INTERNAL SECRETION 



may develop and secrete milk. It seems likely that the 

 interstitial cells are responsible for this effect. 



Lipschiitz concludes that the secretion of the gonads acts in 

 a " sex specific " manner, that is, the male gland aids the 

 development of male sexual characters only while it inhibits 

 the female characters, whereas the female gland promotes the 

 growth of female sexual characteristics, at the same time 

 inhibiting male characters. In birds the development of the 

 male plumage and the spurs does not depend on the male 

 sexual gland, while the ovary converts a male plumage into a 

 female one and inhibits the growth of spurs. The male 

 plumage and the spurs are evolved out of the characters of the 

 hypothetical non-sexual embryonic form, without any influ- 

 ence of the sexual glands. (See however p. 68.) The plumage 

 and spurs become male sexual characters, not because of any 

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

 the development of these non-sexual characters is influenced 

 in the female by the internal secretion of the ovary. Accor- 

 dingly Lipschiitz classifies the sex characters as follows : 



1. Those non-dependent on the " puberty gland " (Steinach) 

 or " interstitial gland." 



2. Those dependent on the puberty gland, which calls forth 

 the characters by acting on the non-sexual embryonic form in 

 the direction of augmentation or inhibition. 



Sand asserts that, by simultaneous transplantation of both 

 ovary and testis into a castrated animal, he has succeeded in 

 obtaining a true experimental hermaphroditism (somatic and 

 psychic). 



The results of ovarian transplantation in the human subject 

 with the object of reducing the symptoms of the artificial 

 menopause after ovariotomy seem to be encouraging. But 

 if the uterus has also been removed, the retention of ovarian 

 tissue is of little benefit. 



Extracts of ovary do not contain any substance of special 

 clirinical or physiological interest. The pharmacodynamical 

 effects of ovarian extracts are found to be the same as those of 

 i '\ tracts from organs and tissues generally, viz., a temporary 

 depression of the arterial blood-pressure brought about by 

 dilatation of arterioles throughout the body. The substance 

 nr -ubstances which produce this effect are not known. They 

 are soluble in alcohol and in ether, as well as water. It has 



