586 THE DESCENT OF MAN. 



Very few male quadrupeds possess weapons of two dis- 

 tinct kinds specially adapted for fighting with rival males. 

 The male muntjac-deer (Cervulus), however, offers an ex- 

 ception, as he is provided with horns, and exserted canine 

 teeth. But we may infer from what follows that one form 

 of weapon has often been replaced in the course of ages by 

 another. With ruminants the development of horns gen- 

 erally stands in an inverse relation with that of even mod- 

 erately developed canine teeth. Tlius camels, guanacoes, 

 chevro tains and musk-deer are hornless, and they have 

 efficient canines; these teeth being ^' always of smaller size 

 in the females than in the males. ''^ The Camelidae have, 

 in addition to their true canines, a pair of canine-shaped in- 

 cisors in their upper jaws.* Male deer and antelopes, on 

 the other hand, possess horns, and they rarely have canine 

 teeth; and these, when present, are always of small size, so 

 that it is doubtful whether they are of any service in their 

 battles. In Antilope montana they exist only as rudiments 

 in the young male, disappearing as he grows old; and they 

 are absent in the female at all ages; but the females of cer- 

 tain other antelopes and of certain deer have been known 

 occasionally to exhibit rudiments of these teeth, f Stallions 

 have small canine teeth, which are either quite absent or 

 rudimentary in the mare; but they do not appear to be used 

 in fighting, for stallions bite with their incisors, and do 

 not open their mouths wide like camels and guanacoes. 

 Whenever the adult male possesses canines, now inefficient, 

 while the female has either none or mere rudiments, we 

 may conclude that the early male progenitor of the species 

 was provided with efficient canines, which have been par- 

 tially transferred to the females. The reduction of these 

 teeth in the males seems to have followed from some change 



manner in which the short-tusked Mooknah variety attacks other 

 elephants. 



*Owen, " Anatomy of Vertebrates," vol. iii, p. 349. 



f See Ruppell (in " Proc, Zooloff. Soc," Jan. 12, 1836, *p. 3) on the 

 canines in deer and antelopes, with a note by Mr. Martin on a female 

 American deer. See also Falconer (** Palaeont. Memoirs and Notes," 

 vol. i, 1868, p, 576) on canines in an adult female deer. In old males 

 of the musk-deer the canines (Pballas, " Spic. Zoolog.," fasc xiii, 

 1779, p. 18) sometimes grow to tlie length of three inches, while in 

 old females a rudiment projects scarcely half an inch above the 

 gums. 



