FUNCTIONS OF QUADRUPEDS. 5 



those which do not extend so far as the sternum are called 

 false ribs. 



The limbs 9 or extremities, are each divided into four 

 parts. Those which belong to the anterior extremities are 

 the shoulders, the arm, the fore-arm, and the hand; and 

 those which belong to the posterior extremities are the hip, 

 the thigh, the leg, and the foot. The shoulder consists of 

 the scapula, or blade-bone, which is placed against the 

 back ; and the clavicle, or collar-bone, attached to the ster- 

 num. In several of the quadrupeds the latter is wanting; 

 but it is always found in those which occasionally use their 

 fore-feet as hands. The scapula, however, is indispensable 

 in all, since the shoulder bone is articulated into a hollow in 

 its anterior angle. The arm, which extends fromJiie 

 shoulder joint to the elbow, is composed of one bone only ; 

 but the fore-arm, which extends from the elbow to the 

 wrist, has two. The hand varies with respect to the num- 

 ber of its bones, in the different species of animals; but the 

 bones which exist in it always form a wrist, the body of the 

 hand, and the fingers. This organization prevails even in 

 birds, which have their ringers enveloped in a skin covered 

 with feathers. It likewise prevails in the amphibious 

 quadrupeds, and the cetacea, in the latter of which the 

 whole of the anterior extremity is reduced externally to the 

 shape of an oar or fin. 



The fore-legs and feet of quadrupeds, besides being instru- 

 ments of motion, are of use to them in several other respects. 

 The predatory species employ them in seizing and retaining 

 their prey ; the monkeys and most of the Glires in conveying 

 food to their mouth ; the Moles and other subterraneous 

 kinds, in digging habitations under the surface of the 

 ground ; and, by means of a thin membrane which connects 

 the greatly elongated fingers, and extends round the hinder 

 part of their body, the bats are enabled to rise into, and flit 



B 3 through 



