THE CATS. a 
upper jaw, from which the whole of the teeth have disappeared. 
On the other hand, in the Cats the object has been to produce 
a type of dentition adapted for seizing and holding a living prey, 
and afterwards devouring it by tearing and cutting off the flesh 
and sinews from the bones, without attempting to crack the 
bones themselves. Consequently, we find that the three pairs 
of incisor teeth in each jaw, characteristic of the older types of 
Mammals, have been retained, and have assumed a pincer-like 
form ; while the tusks, or canines, have been greatly developed, 
‘and project far in advance of the level of the crowns of the 
other teeth. On the other hand, the pre-molar and molar 
teeth, constituting the cheek-series, have been greatly re- 
duced in numbers, their whole strength being, indeed, con- 
centrated on a single pair in each jaw—the carnassial, or 
sectorial teeth—which bite against one another with a scissor- 
like action. 
Assuming it to be a fact that all Mammals have been derived 
from a common ancestral stock, presenting none of the special- 
ised features respectively characteristic of the Antelopes and the 
Cats, these two groups present us the extreme modification 
of which the original stock was susceptible in two opposite 
directions, according to the exigencies of a particular mode of 
life. Before passing on to the consideration of the distinctive 
structural features of the group before us, it may be mentioned 
that the Cats and Antelopes are alike characterised by the pre- 
valence of tawny and rufous hues in their general coloration. 
Moreover, in both groups the ornamentation of the pelage 
takes the form of either spots or stripes ; although among the 
Cats many species have a kind of clouded marking, somewhat 
intermediate between the other two types of coloration. Where- 
as, however, among the Cats, dark transverse stripes are of 
common occurrence, among the Antelopes this kind of orna- 
mentation is met with only in the Zebra-Antelope and the 
B.2 
