MAMMALS 95 



habit of lighting with the head. Thus the aucesters of the 

 reindeer may have had antlers before those of typical deer, 

 and the species may therefore be now in a more advanced 

 stage of evolution, the stage in which the female has inherited 

 the antlers, or rather in which the hereditary tendency latent 

 in the female has manifested itself in the actual development 

 of the antlers. Thus, according to my view, the three stages 

 in the evolution of antlers, and of horns too, are (1) the ex- 

 crescences entirely absent, (2) present in the male only, (3) 

 present in both sexes. 



The evidence concerning the effects of castration on the 

 reindeer is a little uncertain. It is discussed by Caton. 

 The Laplanders castrate their male reindeer at the age of 

 three years, and one whom Caton questioned supposed that 

 the antlers were cast off and renewed after castration as 

 usual. Owen states that this was the case with two cas- 

 trated males at the Zoological Gardens in London. Caton 

 points out, however, that the Laps do not remove the testes, 

 but crush and bruise them, and thinks that the castration is 

 imperfect, and therefore the effect on the antlers is compara- 

 tively slight. He has overlooked the importance of the fact 

 that the female reindeer has antlers. Castration of the male 

 in this species might be expected to reduce the male only 

 to equality with the female, and this probably explains 

 why the effects of castration are less marked than in other 

 species. A character which has been inherited by the female, 

 can no longer be entirely dependent on the functional 

 activity of the male organs of generation. For this reason 

 more exact observations on the effects of castration in male 

 reindeer would be of great importance. 



Another peculiarity of stags is their voice. The roar or 

 bellow of the rutting stag is very deep and loud, and is used 

 chiefly as a challenge to rival stags, but there is no evidence 

 that it lias any importance as a call to the female. Here I 



