74 INFLUENCE OF HORMONES 



I have quoted the evidence concerning the effects 

 of castration on stags in my Sexual Dimorphism and 

 in my paper on the ' Heredity of Secondary Sexual 

 Characters.' ^ When castration is performed soon 

 after birth a minute, simple spike antler is de- 

 veloped, only two to four inches in length : it 

 remains covered with skin, is never shed, and 

 develops no branches. When the operation is 

 performed on a mature stag with antlers, the latter 

 are shed soon after the operation, whether they have 

 lost their velvet or not. In the following season new 

 antlers develop, but these never lose their velvet or 

 skin and are never shed. 



Castration in Fowls 



The removal of the testes from young cocks has 

 been commonly practised in many countries, e.g, 

 France, capons, as such birds are called, being 

 fatter and more tender for the table than entire 

 birds. The actual effect, however, on the secondary 

 sexual characters has not in former times been 

 very definitely described. The usual descriptions 

 represent the castrated birds as having rather fuller 

 plumage than the entire birds ; but the comb and 

 wattles are much smaller than in the latter, more 

 similar to those of a hen. It is also stated that the 

 capon will rear chickens, though he does not incu- 

 bate, and that they are used in this way in France. 



The most precise of the statements on the subject 

 by the earlier naturalists is that of William Yarrell ^ 

 (1857), who writes as follows : — 



' The capon ceases to crow, the comb and gills do 



* ArcJbiv fiir Entwicklungsmechanik, 1908. 

 2 Proc. Linn, Soc, 1857. 



