40 INTERNAL SECRETIONS 



always keeps the male plumage. Pezard found the taiJ 

 feathers of the capon to be sometimes better developed, shinier, 

 and brighter in colour than in the normal male. Similar 

 observations were made on the other feathers of the capon by 

 Goodale. From his own observations Goodale says that if it 

 were not for the narrow comb and barbies the capon would 

 have the appearance of a normal cock {Fig. 27). Pezard 

 records a further observation illustrating in a striking manner 

 the absence of dependence of the male plumage upon the 

 sexual glands ; his capons moulted a year after castration, and 

 again acquired a male plumage. 



As regards the growth of the skeleton, Sellheim found that it 

 is influenced by castration in many ways. Pezard found the 

 neck and the body of the capon to be longer than in the normal 

 cock. Goodale also records that the capon is larger than the 

 normal animal. Sellheim states that the body weight of the 

 full grown capon is about 25 % more than that of the cock. 

 But the greater weight of the capon is due mainly to the greater 

 accumulation of fat, which explains the fact that in relation to 

 the weight of the body as a whole that of the internal organs, 

 such as brain and heart, is smaller than normally. The 

 accumulation of fat is recorded also by Foges, and especially by 

 Pezard, who stated that the quantity of fat is very great. 

 Whereas the fat in the abdominal wall, i.e., the fat remaining 

 after the abdominal organs have been taken away, in a normal 

 animal weighs about 10 to 60 gr., the capon's fat weighs about 

 90 to 250 gr. 



The hypophysis of the castrated cock was found by Fichera 

 to be twice as large as in the normal animal. 



The vas deferens seems to undergo a marked atrophy. As 

 a rule Goodale could not find it in the capon; sometimes it is 

 represented by a thin streak of tissue. 



The changes in the psycho-sexual behaviour caused by 

 prepuberal castration of the cock are evidently more marked 

 than in mammals, although the statements of different 

 authors are sometimes conflicting. As a rule the capon 

 does not crow, and he does not fight with cocks; he shows 

 no interest in the hens and does not tread them. So one 

 may say that the capon in a general way loses the psycho- 

 sexual behaviour of the cock. But Sellheim says that the 

 crow of the capon is hoarser, and shorter than that of the 



