572 TSE DESCENT OF MAN. 



engaged with the English horse, while the other was driv- 

 ing away the mares, and had already separated four from 

 the rest. The capitan settled the matter by driving the 

 whole party into the corral, for the wild stallions would not 

 leave the mares." 



Male animals which are provided with efficient cutting 

 or tearing teeth for the ordinary purposes of life, such as 

 the carnivora, insectivora, and rodents, are seldom furnished 

 with weapons especially adapted for fighting with their rivals. 

 The case is very different with the males of many other 

 animals. We see this in the horns of stags and of certain 

 kinds of antelopes in which the females are hornless. With 

 many animals the canine teeth in the upper or lower jaw, 

 or in both, are much larger in the males than in the 

 females, or are absent in the latter, with the exception 

 sometimes of a hidden rudiment. Certain antelopes, the 

 musk-deer, camel, horse, boar, various apes, seals, and the 

 walrus, offer instances. In the females of the walrus the 

 tusks are sometimes quite absent.* In the male elephant 

 of India and in the male dugoug \ the upper incisors form 

 offensive weapons. In the male narwhal the left canine 

 alone is developed into the well-known, spirally-twisted, so- 

 called horn, which is sometimes from nine to ten feet in 

 length. It is believed that the males use these horns for 

 fighting together; for *^an unbroken one can rarely be got, 

 and occasionally one may be found with the point of 

 another jammed into the broken place."! ^^^^ tooth on 

 the opposite side of the head in the male consists of a rudi- 

 ment about ten inches in length, which is embedded in the 

 jaw; but sometimes, though rarely, both are equally devel- 

 oped on the two sides. In the female both are always rudi- 

 mentary. The male cachalot has a larger head than that 



* Mr. Laraont ("Seasons with the Sea-Horses," 1861, p. 143) says 

 that a good tusk of the male walrus weighs four pounds, and is 

 longer than that of the female, which weighs about three pounds. 

 The males are described as fighting ferociously. On the occasional 

 absence of the tusks in the female, see Mr. R. Brown, " Proc. Zool. 

 Soc," 1868, p. 429. 



f Owen, ' Anatomy of Vertebrates," vol. iii, p. 283. 



tMr. R. Brown, in "Proc. Zool. Soc," 1869, p. 553. See Prof. 

 Turner, in " Journal of Anat. and Phys.," 1872, p. 76, on the homo- 

 logical nature of these tusks. Also Mr. J. W. Clarke on two tusks 

 being developed in the males, in " Proc. Zoolog. Soc.," 1871, p. 42. 



