THE cats. 3 



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 ? 



