RESULTS OF CASTRATION 43 



mistakably similar to a castrated cock {Fig. 29). A more or 

 less marked change to apparent maleness was observed by 

 Goodale in 25 castrated hens. Similar results were obtained 

 by Pezard (1914, 19 15, 19 18) in hens castrated when a few 

 months old. The spurs of these birds about a year after the 

 operations were 2.3 cm. long, i.e., they grew with the same 

 rapidity as in a normal cock. At the time of moulting a 

 change in plumage occurred, the castrated hen acquiring the 

 plumage of a cock (Fig. 30). The characteristic feathers of the 

 neck, the back and the tail were present. And as Goodale and 



^ 



Fig. 30. — Hen castrated four months previously. Male plumage 

 (feathers of neck, back and tail) and spurs. — From a 

 photo of Pezard 's. 



Pezard point out, a castrated hen differs externally from a 

 normal cock only in the smaller comb and in the wattles and 

 barbies. If one does not know the history of such a bird, one 

 cannot decide upon its external appearance whether it is a 

 castrated hen or a castrated cock. Goodale quotes also ex- 

 periments of Guthrie (1910), in which the castrated hen likewise 

 acquired a male plumage. The oviduct was always found by 

 Goodale in the castrated hen. He stated that the oviduct 

 was larger than in the young chick, corresponding in its dimen- 

 sions to the increased size of the bird, but was otherwise 



