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Show 248 SEXUAL SELECTION : MAMMALS. PART lJ. rhinoceros they are said to be shorter in tho femulc. 15 From these various facts we may conclude that horns of all kinds, oven when they are equally developed h1 both sexes, were primarily acquired by the mules in order to conquer other males, and have boon transferred more or less completely to tho female, in relation to the force of the equal form of inheritance. The tusks of the elephant, in the different species or races, differ according to sex, in nearly the sumo manner as tho horns of ruminants. In India and Malacca tho males alone aro provided with well-developed tusks. ':rhe elephant of Ceylon is considered by most naturalists as a distinct race, but by some as a distinct species, and here " not ono in a hundred is found with "tusks, the few that possess them being exclusively "males." 16 The African elephant is undoubteJly 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 mces 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 Antilope bezoartica- tho presence of two tusks in some few male narwhals- tho complete absence of tusks in some female walruses;are all instances of the extreme variability of secondary sexual characters, and of their extreme 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 for other purposes. The elephant uses his tusks 15 Sir Andrew Smith, ' Zoology of S. Africa; pl. xix. Owen, 'Anatomy of Vertebrates,' vol. iii. p. G24. 16 Sir J. Emerson Tennent, 'Ceylon,' 1859, vol. ii. p. 27-:l:. F or Malacca, 'Journal of Indian Archipelago,' vol. iv. p. 357. '"(;uAr. XVII. LAW OF BATTLE. 249 in attacking tho tiger; according to Bruce, he SC'ores the trunks of trees until they can be ttsily thrown ·down, and he likewise thus extracts tho fari111weonR cores of palms ; in Africa he often uses one tusk thiH being always the same, to probe the ground and' thuR to a certain whether it will bear his w ight. 1'ho common bull defends the herd with his horns; and the el~\: in Sweden has been known, according to Lloyd, to stnke a wolf dead with a single blow of his gl'cat horns. 1\Iany similar facts could be given. One of the m~st curious scc?ndary uses to which the horns of any ammal ar occasiOnally put, is that ob erved uy Oa]!taiu H~1tton 17 with the wild goat (Capra mgagrus) of tho Himalaya , and as it is said with the ibex, 11amely, that when the male accidentally falls from a height ho bends inwards his head, and, by alighting on his massive horns, breaks the shock. The female cannot thus use her horns, whieh are smaller, but from her more quiet disposition she does not so much need this strange kind of shield. Each male animal uses his weapons in his own peculiar i~1 hion. The common ram makes a charae and butts with such force with the bases of his horns~ that I ha:e seen a powerful man knocked over as ea~ily as a child. Goats and certain species of sheep, for instance the Ovis cycloceros· of Afghanistan/8 rear on their hind legs, and then not only butt, but "make a cut down "and a jerk up, with the riuued front of their scimitar" shaped horn, as with a sabre. \\hen tlw 0. cycloceros " attacked a large domestic ram, who was a noted "bruiser, he conquered him by the sheer novelty of his 11 'Calcutta Journal of Nat. Hibt.' vol. ii. 184.3, p. ;J2G. 18 l\~r. Blyth, in 'Land aud Water,' 1\IarclJ, IHG7, p. 131, on the nulhonty of Capt. Hutton owl otherl:l. For ih ~ wild l)cmbmkcslJiro goats see the ':Field,' 1bG(J, p. 150. |