286 
SEXUAL SELECTION: MAMMALS. 
Part IL. 
been acquired as ornaments ; and this 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 Nahed Skin , — 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 Didelphis opos- 
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 brigliter than that 
of the female.” Dr. Gray informs me that he 
specified the African squirrels, because, from their un- 
usually bright colours, they best exhibit this differ- 
ence. The female of the Mus minutus of Eussia 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 
OspTiranter rufus, Gould, ‘Mammals of Australia,’ vol. ii. 1863. 
On the Didelphis, Desmarest, ‘ Mammalogie,’ p. 256. 
‘ Annals and Mag. of Nat. Hist.’ Nov. 1867, p. 325. On the Mm 
minutus^ Desmarest, ‘ Mammalogie,’ p. 304. 
J. A. Allen, in ‘ Bulletin of Mus. Comp. Zoolog. of Cambridge, 
United States,’ 1869, p. 207. 
