MAMMALS-ORNAMENTAL COLORS. 52!) 



of hair were gained as ornaments; and this I know is the opinion 

 of some naturalists. If this be correct, there can be little doubt 

 that they were gained or at least modified through sexual selec- 

 tion; but how far the same view may be extended to other mam- 

 mals is doubtful. 



Color of the Hair cmd of the Naked Skin.— I will first give 

 briefiy all the cases known to me, of male quadrupeds differing 

 in color from the females. With Marsupials, as I am informed 

 by Mr. Gould, the sexes rarely differ In this respect; but the 

 great red kangaroo offers a striking exception, "delicate blue 

 "being the prevailing tint in those parts of the female, which 

 "in the male are red."" In the Didelphls opossum of Cayenne 

 the female is said to be a little more red than the male. Of the 

 Rodents Dr. Gray remarks: "African squirrels, especially those 

 "found in the tropical regions, have the fur much brighter and 

 "more vivid at some seasons of the year than at others, and the 

 "fur of the male is generally brighter than that of the female."^" 

 Dr. Gray informs me that he specified the African squirrels, be- 

 cause, from their unusually bright colors, they best exhibit this 

 difference. The female of the Mus minutus of Russia is of a paler 

 and dirtier tint than the male. In a large number of bats the 

 fur of the male is lighter than in the female.^ Mr. Dobson also 

 remarks, with respect to these animals: "Differences, depending 

 "partly or entirely on the possession by the male of fur of a much 

 "more brilliant hue, or distinguished by different markings or 

 "by the greater length of certain portions, are met only, to any 

 "appreciable extent, in the frugivorous bats in which the sense 

 "of sight is well developed." This last remark deserves attention, 

 as bearing on the question whether bright colors are serviceable 

 to male animals from being ornamental. In one genus of 

 sloths, it is now established, as Dr. Gray states, "that the males 

 "are ornamented differently from the females — that is to say, 

 "that they have a patch of soft short hair between the shoulders, 

 "which is generally of a more or less orange color, and in one 

 "species pure white. The females on the contrary, are destitute of 

 "this mark." 



The terrestrial Carnivora and Insectivora rarely exhibit sexual 

 differences of any kind, including color. The ocelot (Felis par- 



i» Osphranter rufus, Gould, 'Mammals of Australia,' 1863, vol. ii. On 

 the Didelphis, Desmarest, 'Mammalogle,' p. 256. 



™ 'Annals and Mag-, of Nat. Hist.' Nov. 1867, p. 325. On the Mus 

 minutus, Desmarest, 'Mammalogie,' p. 304. 



21 J. A. Allen, in 'Bulletin of Mus. Comp. Zoolog-. of Cambridge, 

 United States,' 1869, p. 207. Mr. Dobson on sexual characters in the 

 Chiroptera, 'Proc. Zoolog. Soc' 1873, p. 241. Dr. Gray on Sloths, ibid. 

 1871, p. 436. 

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