280 SEXUAL SELECTION: MAMMALS. [Part IL 



skin rouiul the tail, of a brilliant carmine red, which pe- 

 riodically becomes, as I was assured by the keepers in the 

 Zoological Gardens, even more vivid, and her face is also 

 pale red. On the other hand, with the adult male and with 

 the young of both sexes, as I saw in the Gardens, neither 

 the naked skin at the posterior end of the body, nor the 

 face, shows a trace of red. It appears, however, from some 

 published accounts, that the male does occasionally, or 

 during certain seasons, exhibit some traces of the red. 

 Although he is thus less ornamented than the female, yet 

 in the larger size of his body, larger canine teeth, more 

 developed whiskers, more prominent superciliary ridges, 

 he follows the common rule of the male excelling the 

 female. 



I have now given all the cases known to me of a dif- 

 ference in color between the sexes of mammals. The 

 colors of the female either do not differ in a sufficient 

 degree from those of the male, or are not of a suitable 

 nature to afford her jjrotection, and therefore cannot be 

 explained on this principle. In some, perhaps in many 

 cases, the differences may be the result of variations con- 

 fined to one sex and transmitted to the same sex, without 

 any good having been thus gained, and therefore without 

 the aid of selection. We have instances of this kind with 

 our domesticated animals, as in the males of certain cats 

 being rusty-red, while the females are tortoise-shell col- 

 ored. Analogous cases occur under nature : Mr. Bartlett 

 has seen many black varieties of the jaguar, leopard, vul- 

 pine, plialaiiger, and wombat; and he is certain that all, 

 or nearly all, were males. On the other hand, both sexes 

 of wolves, foxes, and apparently of American squirrels, 

 are occasionally born black. Hence it is quite possible 

 that with some mammals the blackness of the males, es- 

 pecially when this color is congenital, may simply be the 



