388 



INTRODUCTION TO ZOOLOGY. 



Skeleton. By far the greater number of the animals be- 

 longing to this class move on the ground by the action of 

 four feet, from which circumstance the name quadruped has 

 been restricted to them. It is occasionally used in a more 

 general sense, as synonymous with the scientific term mam- 

 malia. The outline of the skeleton conveys, in most cases, 

 an idea of that of the body; but occasionally, as in the hump 

 of the Camel (Fig. 289), there exists in the living animals 



Fig. 289. SKELETON OF CAMEL.* 



some peculiarly striking feature, which is not represented in 

 the bony framework. The hump, in the present instance, 

 consists of fatty tissue, and is well known to diminish in size, 

 and nearly to disappear when the animal is exposed to long- 

 continued privation. 



The possession of four feet used for the purposes of loco- 

 motion, though general in the mammalia, is by no means 



* Fig, 239. Skeleton of the Camel on a black ground, exhibiting an outlin. 

 of the animal: vc, cervical vertebrae; vd, dorsal vertebrae; vl, lumbar vertebrae; 

 vs, sacral vertebrae ; vg, caudal vertebrae ; e, ribs ; o, scapula ; h, humerus ; cu 

 bone of fore-arm ; ca, carpus ; me, metacarpus ; ph, phalanges ; fe, femur ; ro, 

 patella; ti, tibia ; ta, tarsus ; mt, metatarsus. In/g. 290, the corresponding parts 

 are indicated by the same letters as in fig. 289. 



