MAMMALS. 617 



marked colors and other ornamental characters of male 

 quadrupeds are beneficial to them in their rivalry with 

 other males, and have consequently been acquired through 

 sexual selection. This view is strengthened by the dif- 

 ferences in color between the sexes occurring almost ex- 

 clusively, as may be collected from the previous details, in 

 those groups and sub-groups of mammals which present 

 other and strongly marked secondary sexual characters; 

 these being likewise due to sexual selection. 



Quadrupeds manifestly take notice of color. Sir S. 

 Baker repeatedly observed that the African elephant and 

 rhinoceros attacked white or gray horses with special fury. 

 I have elsewhere shown* that half-wild horses apparently 

 prefer to pair with those of the same color, and that herds 

 of fallow-deer of different colors, though living together, 

 have long kept distinct. It is a more significant fact that 

 a female zebra would not admit the addresses of a male ass 

 until he was painted so as to resemble a zebra, and then, as 

 John Hunter remarks, "she received him very readily. 

 In this curious fact, we have instinct excited by mere 

 color, which had so strong an effect as to get the better of 

 evsrything else. But the male did not require this; the 

 female being an animal somewhat similar to himself, was 

 sufficient to rouse him." f 



In an earlier chapter we have seen that the mental 

 powers of the higher animals do not differ in kind, though 

 greatly in degree, from the corresponding powers of man, 

 especially of the lower and barbarous races; and it would 

 appear that even their taste for the beautiful is not widely 

 different from that of the Quadrurnana. As the negro of 

 Africa raises the flesh on his face into parallel ridges " or 

 cicatrices, high above the natural surface, which unsightly 

 deformities are considered great personal attractions;"! as 

 negroes and savages in many parts of the world paint their 

 faces with red, blue, white or black bars so the male man- 

 drill of Africa appears to have acquired his deeply furrowed 

 and gaudily colored face from having been thus rendered 



*."The Variation of Animals and Plants under Domestication." 

 1868, vol. ii, pp. 102, 103. 



f " Essays and Observations by J. Hunter," edited by Owen, 1861, 

 vol. i, p. 194. 



JSir S. Baker, "Tlie Nile Tributaries of Abyssinia," 1867. 



