286 SEXUAL SELECTION : MAMMALS. Part IL 



been acquired as ornaments ; and tliis I know is the 

 opinion of some naturalists. If this view be correct, 

 there can be little doubt that they have been acquired, 

 or at least modified, through sexual selection. 



Colour of the Hair and of the NaJced SJdii. — I will 

 first give briefly all the cases known to me, of male 

 quadrupeds differing in colour from the females. With 

 Marsupials, as I am informed by Mr. Gould, the sexes 

 rarely differ in this respect ; but the great red kan- 

 garoo' offers a striking exception, "delicate blue being 

 " the prevailing tint in those parts of the female, 

 " which in the male are red." ^^ In the I)idel]jh{s ojoos- 

 sum of Cayenne the female is said to be a little more 

 red than the male. With Eodents Dr. Gray remarks : 

 " African squirrels, especially those found in the tropi- 

 '• cal 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, because, from their rni- 

 usually bright colours, they best exhibit this differ- 

 ence. The female of the Mus minidus of Kussia is of 

 a paler and dirtier tint than the male. In some few 

 bats the fur of the male is lighter and brighter than 

 in the female.^^ 



The terrestrial Carnivora and Insectivora rarely ex- 

 hibit sexual differences of any kind, and their colours 

 are almost always exactly the same in both sexes. The 



^^ Osphranter rufiis, GonltL 'Mammals of Australia,' vol. ii. 1863. 

 On the Diclelpliis, Desmarest, ' Mammnlogie,' p. 256. 



20 ' Annals and Mag. of Nat. Hi>t.' Nov. 1867, p. 325. On the Mus 

 minutus, Desmarest, ' Mannnalogie,' p. 304. 



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

 United States,' 1869, p. 207. 



