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Show 282 SEXUAL SELECTION : MAMMALS. T'ART 11. when a thin and narrow crest runs along the whole lcno-th of the back· for a crest of this kind would 0 ' afford scarcely any protection, and the ridge of the baek is not a likely place to be injured; nevertheless such crests are sometimes confined to the males, or are much more developed in them than in the fema1es. Two antelopes, the T1·agelaphus scriptus 13 (see fig. 68, p. 300) and Portax picta, may be given as instances. The crests of certuin stags and of the male wild goat stand erect, when these animals are enraged or terrified ;14 but it can hardly be supposed that they have been acquired for tho sake of exciting fear in 'their enemies. One of the above-named antelopes, the Portax picta, has a large well-defined brush of black hair ~n the throat, and this i.s much larger in the male than m the female. In tho Ammot1•agus tragelaph'us of North Africa, a member of the sheep-family, tho ii-ont-legs arc almost concealed by an extraordinary growth of hair, which depends from the neck and up1Jer halves of the legs; but Mr. Bartlett does not believe that this mantle is of the least use to the male, in whom it is much more developed than in the female. Male quadrupeds of many kinds differ from the females in having more hair, or hair of a different character, on certain parts of their faces. Tho bull alone has curled hair on the forehead. 15 In three closely-allied sub-genera of the goat family, the males alone possess beards, sometimes of large size ; in two other sub-genera both sexes have a beard, but this 13 Dr. Gray,' Gleanings from tho Menagerie at KnowolC'y,' pl. 28. 14 Judge Caton on the wapiti, 'Transact. Otlawa Acad. Nut. Sciences,' 1868, p. 3G, 40 ; Blyth, 'Land and Water,' on Cct]J7'a a:ga· ·grus, 18G7, p. 37. H 'Hunter's Essnys and Observations,' edited by Owen, 1861, vol. i. p. 236. Cn.A.r. XVIII. DEVELOPMENT OF HAlll. 283 disappears in some of the domestic breeds of the common goat; and neither sex of the Hemitragus has a beard. In the jbex the beard is not developed during the summer, and is so smalL at other seasons that it may be called rudimentary.16 With some monkeys the beard is confined to the male, as in the Orang, or is Fig. 66. l'ltheciu Sutuuus, 11111le (from 13rehm). much larger in tho malo than in the female, as in the Mycetes ca1·aya and Pithecia satanas (fig. 66). So it is with the whiskers of some species of l\Iacacus/7 and, as we have seen, with the manes of some species of baboons. 16 Sec Dr. Grny's 'Cat. of 1\Iammai:a in BriLish 1\Iuscum,' part iii. 1852, p. IH. 17 Rengger, 'Sliugcthierc,' &c., s. H:; Desmarcd, '1\Tammalogie,' p. ·G6. |