MAMMALIA 357 



of other animals, which they catch by cunning, by chasing, or 

 by stealthily creeping up upon them and pouncing on them, 

 whereupon they bite and tear them in pieces. Here we find 

 another striking illustration of the adaptation of structure to 

 habits. They must be fitted to attack and destroy other ani- 

 mals. Their five or four toes are armed with sharp claws, which, 

 in the cat, are retractile into a sheath by which they are pro- 

 tected when not in use. The teeth are adapted for seizing, 

 biting, holding or cutting, in contrast to the nibbling or grind- 

 ing teeth of the herbivores. The usually six incisor teeth are 

 small. The canines are long, strong, and conical, fitted for 

 tearing, and the premolar in the upper jaw and the first molar 

 in the lower jaw, called the " carnassial teeth," are developed 

 into thin, sharp, three-pointed fangs, shutting down past one 

 another like scissor-blades, while the cusps of the molars form 

 more or less angular and sharp ridges. 



The stomach is simple, and the cecum small or wanting. 

 The clavicle is reduced, the radius and ulna well developed. 

 As to manner of walking, there are several gradations from the 

 plantigrade bears, which walk on the soles of their feet, to the 

 digitigrade cats, which walk on the tips of their toes. The 

 coloration is varied to conform to their habits. Some are 

 spotted, others striped, while many adults are quite modest in 

 their plain, uniform colors. The brain is large and well convo- 

 luted, and the sense organs well developed, giving them a high 

 degree of intelligence. 



This provision of nature, wherein some animals feed upon 

 vegetable matter and others feed upon animals — for every living 

 thing, from the microscopic algse in the water to large animals 

 like the deer and horse, becomes food for some animal — is a 

 wise one. For thus the vegetation of the earth supports not only 

 the herbivorous animals feeding directly upon it, but the carniv- 

 orous animal has his food very largely prepared for him by the 

 vegetable-feeding animals. But the carnivorous animal also 

 aids the herbivorous survivors in their struggle for existence, for, 

 was not the number kept within bounds, the rapidly multiply- 

 ing herbivores would soon absolutely destroy the vegetation of 

 the world. 



These animals are usually clothed in dense, soft hair, and 



