248 
SEXUAL SELECTION- : MAMMALS. 
Part 
rhinoceros they are said to be shorter in the female. 15 
From these various facts we may conclude that hor» s 
of all kinds, even when they are equally developed & 
both sexes, were primarily acquired by the males & 
order to conquer other males, and have been tra» s ' 
f erred more or less completely to tiie female, in relation 
to the force of the equal form of inheritance. 
4 he tusks o( the elephant, in the different species ,a * 
races, differ according to sex, in nearly the same man |ier 
as the horns of ruminants. In India and Malacca tl> 0 
males alone are provided with well-developed tusk* 
4he elephant of Ceylon is considered by most 11 a ” 
tuialists as a distinct race, but by some as a distiu*^ 
species, and here “ not one in a hundred is found 
“tusks, the few that possess them being exclusive!/ 
“ males.” 16 The African elephant is undoubtedly ^ 
tmet, and the female has large, well-developed tusk* 
though not so large as those of the male. These d#' 
feiences in the tusks ol the several races and species 
elephants— the great variability of the horns of deed 
as notably in the wild reindeer — the occasional p re ' 
seuce of horns in the female Antilope lezoartica—^ 0 
presence of two tusks in some few male narwhals-'* 0 * 3 
complete absence of tusks in some female walruses,"' 
are all Instances of the extreme variability of second a 1 '/ 
® e * ual . chai ' a<; ters, and of their extreme liability t0 
differ m closely-allied forms. 
Although tusks and horns appear in all cases to h llV0 
been primarily developed as sexual weapons they ol* e ° 
serve for other purposes. The elephant uses his tusks 
15 Sir Andrew Smith, ‘ Zoology of S. Africa,’ pi. xix. Owen, ‘A 119 ' 
tomy of Vertebrates,’ vol. iii. p. 624. 
18 Sir J. Emerson Tennent, ‘Ceylon,’ 1S59, vol. ii p. 274. 
Malacca, ‘Journal of Indian Archipelago,’ vol. iv. p. 357. 
