610 THK DESCENT OF MAN. 



the male is generally brighter than that of the female."* 

 Dr. Gray informs me that he specified the African squir- 

 rels, because, from their unusually bright colors, they best 

 exhibit this difference. The female of the Mus mimitus 

 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 

 female, f 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 ser- 

 viceable 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 pardalis), however, is exceptional, for the colors of 

 the female, compared with those of the male, are '^moins 

 apparentes, le fauve, etant plus terne, le blanc moins pur, 

 les raies ayant moins de largeur et les taches moins de 

 diametre."J; The sexes of the allied i^eZis mitis also differ, 

 but in a less degree; the general hues of the female being 

 rather paler than in the male, with the spots less black. 

 The marine Carnivora or seals, on the other hand, some- 

 times differ considerably iu color, and they present, as we 

 have already seen, other remarkable sexual differences. 

 Thus the male of the Otaria nigresceiis of the southern 

 hemisphere is of a rich brown shade above ; while the 



* " Annals and Mag. of Nat. Hist.," Nov., 1867, p. 325. On tlie 

 Mus minutiis, Desmarest, "Mammalogie," p. 304. 



f 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. 



!: Desmarest. " Mammalogie," 1820, p. 220. On Felis Mitis, Reng- 

 ger, ibid, s. 194. 



