236 SEXUAL SELECTION: MAMMALS. [Part II. 



oped, as Mr. Winwood Reade informs me, in the castrated 

 male ; so that they are affected in this respect like the horns 

 of stags. In some breeds, as in that of North Wales, 

 in which both sexes are properly horned, the ewes are 

 very liable to be hornless. In these same sheep, as I have 

 been informed by a trustworthy witness who purposely 

 inspected a flock during the lambing-season, the horns at 

 birth are generally more fully developed in the male than 

 in the female. With the adult musk-ox ( Ovibos moscha- 

 tus) the horns of the male are larger than those of the 

 female, and in the latter the bases do not touch. 13 In re- 

 gard to ordinary cattle Mr. Blyth remarks : " In most of 

 the wild bovine animals the horns are both longer and 

 thicker in the bull than in the cow, and in the cow-ban- 

 teng (Bos sondaicus) the horns are remarkably small, 

 and inclined much backward. In the domestic races of 

 cattle, both of the humped and humpless types, the horns 

 are short and thick in the bull, longer and more slender 

 in the cow and ox ; and in the Indian buffalo they are 

 shorter and thicker in the bull, longer and more slender 

 in the cow. In the wild-gaour (B. gaurus) the horns are 

 mostly both longer and thicker in the bull than in the 

 cow." 14 Hence with most sheath-horned ruminants the 

 horns of the male are either longer or stronger than those 

 of the female. With the Rhinoceros simus, as I may here 

 add, the horns of the female are generally longer but less 

 powerful than in the male ; and in some other species of 

 rhinoceros they are said to be shorter in the female. 15 

 From these various facts we may conclude that horns of 

 all kinds, even when equally developed in both sexes, 

 were primarily acquired by the males in order to conquer 



13 Richardson, ' Fauna Bor. Americana,' p. 278. 



14 l Land and water,' 1867, p. 346. 



15 Sir Andrew Smith, ' Zoology of South Africa,' pi. xix. Owen, ' Anat* 

 omy of Vertebrates,' vol. ill. p. 624. 



