312 INTERNAL SECRETIONS 



sex and inhibited by the secretion of the gonad of the opposite 

 sex." 



It is of great interest to note that the castrated hen or duck 

 can acquire some male characters which depend normally 

 upon the internal secretion of the testicle. Such observations 

 were made by Goodale (hens and ducks), by Pezard (hens) and 

 by Zawadowsky (hens). In the experiments of Goodale the 

 comb developed in castrated hens in varying degrees, becoming 

 very large and male-like in some of them, but remaining com- 

 paratively small in others; there is according to Goodale no 

 clear evidence as to the cause of this difference. The trans- 

 formation of female characters into male ones seems to be 

 related to a transformation of the rudiment of the sex gland 

 on the right side in the female bird. Now Zawadowsky (1922, 

 p. 82) observed a development of male sex characters (comb, 

 wattles, and, to a certain degree also, sexual activity) in 

 castrated hens in which there was no transformation of the 

 right rudiment. One of his castrated hens showed a growth 

 of the comb as in the male. In this bird a regeneration of the 

 left ovary occurred, but no ova were present. After removal 

 of this regenerated gland a regression of the comb took place 

 as in the ordinary "castrate." Zawadowsky concludes from 

 these observations that the ovary may in certain circumstances 

 elaborate male sexual hormones. 



The question arises as to whether the specific hormonic effect 

 characteristic of the testicle or the ovary can be exhibited 

 also by other endocrine glands. It cannot be denied that in 

 every specific hormonic effect produced by the gonads other 

 endocrine glands are actively involved; but there is no ex- 

 perimental evidence that a sex specific action similar to that 

 of the gonad is exhibited by other glands, with the one possible 

 exception of the adrenals. We shall deal with these questions 

 below in the chapter on "Intersexuality." 



C. EXPERIMENTS ON ARTHROPODA. 



Experiments on moths have been performed by Meisen- 

 heimer (1909) and Kopec (1912). Meisenheimer castrated the 

 male Lymantria dispar at the caterpillar stage and implanted 

 ovaries. The latter developed quite normally, but the animals 

 never showed any transformation of the sex characters. The 

 vasa deferentia, the vesicles, the accessory glands and the 



