REPRODUCTION 23 



If the young male is castrated, the external appearance 

 of the animal undergoes a gradual change. The whole 

 aspect becomes less masculine. The shoulders, neck 

 and crest develop relatively to a much less extent. The 

 hind quarters are relatively better developed in the 

 castrated animal. The temperament and disposition 

 undergo radical changes. The bull castrated before 

 puberty fails to develop the heavy head and horns, curly 

 hair and protruding eye characteristic of this animal. In 

 swine, castration prevents the development of the shoulder 

 plates and tusks. The horns of sheep are very greatly 

 dwarfed, though the same effect is not so marked in cattle. 

 The removal of the testicles also influences the physiolog- 

 ical constitution of the animal. It is well known that 

 oxen grow larger and heavier than the uncastrated bulls. 

 The same result is observed in capons which often grow 

 to a much greater weight than the normal male. The 

 castration of old boars results in the disappearance of 

 the strong odor characteristic of the flesh, and their food 

 value is thereby increased. 



The removal of the ovaries (spaying) of the female 

 is followed by phenomena similar to those observed in 

 the castrated male. The spayed female loses her feminine 

 appearance and approaches the male in general char- 

 acter. Like the male, the disposition becomes quieter 

 and the general physiological condition of the animal 

 favors more rapid laying on of fat. 



At the Massachusetts Experiment Station, Goodale 1 

 castrated a brown Leghorn cockerel at twenty-four days 

 old. At the same time the fresh ovaries of two brood 

 sisters were cut in several pieces and placed under the 

 skin of the castrated cockerel. The bird developed in 



1 Goodale, "Science," Vol. 40 (1914), p. 549. 



