42 INTERNAL SECRETIONS 



As concerns postpuberal castration of cocks, Poll (1909) 

 described an atrophy of the comb and wattles, but no change 

 in plumage. Pezard (1912, 1918, pp. 57-82) made similar 

 statements (Fig. 28) and studied the atrophy of the comb in 

 the piostpuberally castrated cock from an exact quantitative 

 point of view. If the castration is a complete one, the results 

 of the operation may be observed after a few days. For 

 details the original papers of Pezard may be referred to (1919, 

 1920, 1921). Besides the atrophy of the erectile organs, the 

 capon ceases to crow and loses its sexual instincts. i\s with 

 the plumage, there are also no changes in the spurs. If the 

 castration was an incomplete one, atrophy of the sexual 

 characters does not occur. 



? 



Fig. 29. — Ovariotomized pullet. Male plumage and 

 spurs. Compare with Fig. 27; great similarity 

 between castrated cock and castrated hen. — 

 Reproduced from a coloured plate of Goodale's. 



In view of the intimate relation between the sexual characters 

 and the sexual glands in mammals it may seem difficult to 

 explain why some of the sexual characters such as the plumage 

 and the spurs develop independently of the sexual glands. 

 But this can be understood if we compare the castrated cock 

 with the castrated hen. 



Goodale (1913, 1916) castrated Brown Leghorn hens at an 

 age of four weeks to four months. These hens acquired a male 

 plumage. The plumage was more like that of a capon than 

 that of a normal cock, the feathers being longer. Spurs were 

 developed. So the castrated hen is in her external appearance 



