494 CARNIVORES. 
which respect they are markedly different from both the civets and the coatis. 
The general coloration of the dogs varies from grey to a yellowish or reddish- 
brown; the upper-part of the head and back, as well as some portions of the limbs, 
being generally darker than the flanks, while the under-parts are paler. The outer 
surfaces of the ears may be distinctively coloured, and there is often a dark mark 
between the eye and the nose, and another near the tail; but, as a rule, stripes or 
patches differing in hue from the ground-colour of the fur are absent, or ill-defined. 
In spite, however, of this general uniformity of coloration, many of the species are 
subject to an extraordinary amount of either individual or seasonal variation, both 
in respect of colour, and also as regards the length of their fur. In consequence of 
such variations much uncertainty has prevailed as to the number of species. 
Professor Mivart gives the probable number as thirty-five, but he reckons a 
few forms which other writers do not consider entitled to rank as more than 
varieties, while some 
F of the forms which 
it he considers to be 
varieties are regarded 
as species by others. 
fi" 
a a. 
MS G 0 
(G 
Thetotal number may, 
therefore, be roughly 
estimated at a little 
below forty. 
As regards the 
seasonal and in- 
dividual variation in 
the coloration of dogs, 
it may be observed 
that the hue of the 
fur is generally 
in winter 
SKELETON OF WOLF, hghter 
than in summer ; this 
difference attaining its maximum in the Arctic fox, of which the usual winter 
pelage is pure white. Then again, among those species or races inhabiting 
high latitudes or mountains, the fur is considerably longer in winter than in 
summer. Moreover, as with the cats, some species show more or less marked 
tendencies to the development of black individuals. Again, and especially among 
the foxes, the colour of different individuals or races of a single species may 
vary from a greyish, through a yellowish, to a reddish tinge; while, if the general 
colour remains the same, there may be darker or lighter shades. Added to these 
variations in the coloration and length of the fur, there may also be a large 
amount of individual difference in point of size in the same species. 
A peculiar character of many dogs, and one in which they differ markedly 
from the cats, is their habit of associating in large packs for the purpose of 
hunting their prey. In general, such prey is pursued chiefly or entirely by the 
aid of smell, which attains an extraordinary development in some members of 
the group. This keen perception of scent is not, however, accompanied by any 
