MAMMALS. 575 



tions we may conclude that the possession of fairly, well- 

 developed horns by the female reindeer is due to the males 

 having first acquired them as weapons for fighting with 

 other males; and secondarily to their development from 

 some unknown cause at an unusually early age in the males 

 and their consequent transference to both sexes. 



Turning to the sheath-horned ruminants: with ante- 

 lopes a graduated series can be formed, beginning with 

 species, the females of which are completely destitute of 

 horns passing on to those which have horns so small as to 

 be almost rudimentary (as with the Antilocapra americana, 

 in which species they are present in only one out of four 

 or five females*) to those which have fairly developed 

 horns, but manifestly smaller and thinner than in the 

 male and sometimes of a different shapef and ending 

 with those in whicli both sexes have horns of equal size. 

 As with the reindeer, so with antelopes, there exists, as 

 previously shown, a relation between the period of the devel- 

 opment of the horns and their transmission to one or both 

 sexes; it is therefore probable that their presence or ab- 

 sence in the females of some species and their more or less 

 perfect condition in the females of other species depends, 

 not on their being of any special use, but simply in inherit- 

 ance. It accords with this view that even in the same 

 restricted genus both sexes of some species, and the males 

 alone of others, are thus provided. It is also a remarkable 

 fact that, although the females of Antilope hezoartica are 

 normally destitute of horns, Mr. Blyth has seen no less 

 than three females thus furnished; and there was no reason 

 to suppose that they were old or diseased. 



In all the wild species of goats and sheep the horns are 

 larger in the male than in the female, and are sometimes 

 quite absent in the latter. J In several domestic breeds of 

 these two animals, the males alone are furnished with 



British Maseum," part iii, p. 220. On the Cervus canadensis or 

 wapiti, see Hon. J. D. Caton, "Ottawa Acad, of Nat. Sciences," May, 

 1868, p. 9. 



* I am indebted to Dr. Canfield for this information; see also his 

 paper in " Proc. Zoolog. Soc," 1866, p. 105. 



+ For instance, the horns of the female Ant. eneJtore resemble those 

 of a distinct species, viz., the A7it. dorcas var. Gorine, see Desmarest, 

 ** Mammalogie," p. 455. 



JGray, "Catalogue Mamm. Brit. Mus.," part iii, 1852, p. 160. 



