48 H. D. GOODALE. 



is similar to the loss of power by the castrated stag of renewing 

 the antlers each year. Whether castration of the drake, very 

 early in life, will prevent the assumption of the breeding plumage 

 will be determined later. 



Removal of the ovary, however, has an entirely different re- 

 sult. The female after a time may gradually lose her normal 

 characters and assume those of the male. The results entirely 

 confirm previous observations along this line. Darwin records 

 a duck which in old age assumed the perfect winter and summer 

 plumage of the drake. Korscheldt also records a similar case. 



Similar changes occur in fowls. The capon is well known. 

 He is larger, heavier, "softer" and more sluggish than the normal 

 male. He is said never to crow. Comb and wattles are poorly 

 developed, but the other secondary sexual characters may be fully 

 developed. Shattock and Seligmann, however, appear to have 

 found that this development takes place only when some testicular 

 material remains behind. But the age of the bird when castrated 

 may have an important bearing on this point. Stags when cas- 

 trated very young develop only a very small spike, though the 

 castrated adult retains large antlers. Likewise, a bull, castrated 

 when mature (called a "stag"), differs little from the normal adult. 

 The bull, castrated as a calf, on maturing differs in several 

 respects from the normal adult. Castration of the cockerel, 

 then, has two results. First, it may result in the failure of some 

 of the secondary sexual characters to develop; second, it brings 

 about certain other modifications not associated with secondary 

 sexual characters. There is an interesting peculiarity of the 

 capon. He is said to be capable of being trained to brood and 

 care for chicks. It is doubtful, though, if this is the acquirement 

 of a female sexual character, for he apparently does not become 

 broody, but merely is easily trained to care for the chicks. 

 Poulards are less well known, but may be expected to develop 

 male characters. Waterton records such a case, not resulting, 

 however, from surgical castration (cited by Darwin). 



In mammals the general results seem to be quite similar. The 

 castrated female is commonly supposed to assume male char- 

 acters. The male on the other hand merely fails to develop 

 his secondary sexual characters, which remain in a more or less 



