2S6 
SEXUAL SELECTION: MAMMALS. 
Part ‘ 
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 Shin . — I "'ill 
first give briefly all the cases known to me, of imd e 
quadrupeds differing in colour from the females. With 
Marsupials, as I am informed by Mr. Gould, the sexe s 
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 .” 19 In the Didelphis opos- 
sum of Cayenne the female is said to be a little more 
red than the male. With Rodents 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 .” 20 Dr. Gray informs me that h e 
specified the African squirrels, because, from their un- 
usually bright colours, they best exhibit this diff e,v 
enee. The female of the Mus minutus of Russia is 
a paler and dirtier tint than the male. In some f«" 
bats the fur of the male is lighter and brighter than 
in the female . 21 
The terrestrial Carnivora and Insectivora rarely eX ' 
hibit sexual differences of any kind, and their colon 
are almost always exactly the same in both sexes. The 
19 Osphranter rufn s, Gould. ‘Mammal- of Australia.’ vcl. ii. 1 8 ° 3 ' 
On tlic Didelphis, D< smnrost, * Mumnmlogie,’ p. 250. 
20 ‘Annals and Mag. of Nat. IIi»t.’ Nov. 1867, p.':l25. On the M* 1 
minutus, Desmarest, 1 Mammalogie,’ p, 604. 
21 J- A. Allen, in ‘ Bulletin of Mus. Comp. Zoolog. of Cambridge- 
United States,’ ISO!), p. 207. 
