Jhap. XVII. Mammals — Law of Battle. 507 



condition of the horns in some early progenitor of* eacli species. 

 But why castration should lead to the reappearance of an early 

 condition of the horns cannot be explained with any certainty 

 Nevertheless, it seems probable, that in nearly the same manner 

 as the constitutional disturbance in the offspring, caused by a 

 cross between two distinct species or races, often leads to the 

 reappearance of long-lost characters ; 19 so here, the disturbance 

 in the constitution of the individual, resulting from castration, 

 produces the same effect. 



The tusks of the elephant, in the different species or races, 

 differ according to sex, nearly as do the horns of ruminants. In 

 India and Malacca the males alone are provided with well- 

 developed tusks. The elephant of Ceylon is considered by most 

 naturalists as a distinct race, but Ly some as a distinct species, 

 and here " not one in a hundred is found with tusks, the few 

 " that possess them being exclusively males." 20 The African 

 elephant is undoubtedly distinct, and the female has large well- 

 developed tusks, though not so large as those of the male. 



These differences in the tusks of the several races and species 

 of elephants — the great variability of the horns of deer, as 

 notably in the wild reindeer — the occasional presence of horns 

 in the female Antelope bezoartica, and their frequent absence in 

 the female of Antilocapra americana — the presence of two tusks 

 in some few male narwhals — the com plete absence of tusks in some 

 female walruses — are all instances of the extreme variability of 

 secondary sexual characters, and of their liability to differ in 

 closely-allied forms. 



Although tusks and horns appear in all cases to have been 

 primarily developed as sexual weapons, they often serve other 

 purposes. The elephant uses his tusks in attacking the tiger ; 

 according to Bruce, he scores the trunks of trees until they can 

 be thrown down easily, and he likewise thus extracts the fari- 

 naceous cores of palms ; in Africa he often uses one tusk, always 

 the same, to probe the ground and thus ascertain whether it will 

 bear his weight. The common bull defends the herd with his 

 horns; and the elk in Sweden has been known, according to 

 Lloyd, to strike a wolf dead with a single blow of his great 

 horns. Many similar facts could be givem One of the most 

 curious secondary uses to which the horns of an animal may 

 be occasionally put, is that observed by Captain Hutton 2 ' with 



M I have given various experi- 20 Sir J. Emerson Tennent, ' Cev- 



<nents and other evidence proving ion,' 1859, vol. ii. p. 274. For 



that this is the ca-e, >n my ' Varia- Malacca, 'Journal of Indian Archi- 



ticn of Animals and Plants under pelago,' vol. iv. p. 357, 



Domestical ion,' vol. ii., 1868, pp. 39 21 'Calcutta Journal of Nat. Hist. 



-47. -col. ii. 1843, p. 520. 



