Chap. XVIII. 
EQUAL TEANSMISSION. 
299 
mionus, the domestic cow, two species of antelopes, the 
musk-deer, the roe, the elk, and reindeer. The roe, 
for instance, has a red summer and a greyish-white 
winter coat ; and the latter may perhaps serve as a 
protection to the animal wdiilst wandering through the 
leafless thickets, sprinkled with snow and hoar-frost. 
If the above named animals were gradually to extend 
their range into regions perpetually covered with snow, 
their pale winter-coats would probably be rendered, 
through natural selection, whiter and whiter by de- 
grees, until they became as white as snow. 
Although we must admit that many quadrupeds have 
received their present tints as a protection, yet with a 
host of species, the colours are far too conspicuous and 
too singularly arranged to allow us to suppose that they 
serve for this purpose. We may take as an illustra- 
tion certain antelopes: when we see that the square 
white patch on the throat, the white marks on the fet- 
locks, and the round black spots on the ears, are all 
more distinct in the male of the Portax ^icta, than in 
the female; — when we see that the colours are more 
vivid, that the narrow white lines on the flank and 
the broad white bar on the shoulder are more distinct 
in the male Oreas Derby anus than in the female; — 
when we see a similar difference between the sexes 
of the curiously-ornamented Tragelaphus scriptus (fig. 
68), — we may conclude that these colours and various 
marks have been at least intensified through sexual 
selection. It is inconceivable that such colours and 
marks can be of any direct or ordinary service to these 
animals ; and as they have almost certainly been inten- 
sified through sexual selection, it is probable that they 
were originally gained through this same process, and 
then partially transferred to the females. If this view 
be admitted, there can be little doubt that the equally 
