ORDER CARN1VORA ; GENERAL CHARACTERS. 



205 



to be plantigrade. The Cats are an example of the first ; the 

 Bears of the second. The conformation of the extremities in the 

 Seals offers a third variety ; for their bones are flattened and 

 shortened, but spread out from one another, so as to give support 

 to the fin- like expansion of the skin, that envelopes and connects 

 them nearly to their extremities. In all instances the phalan- 



geal bones are terminated by 

 claws, which are both strong 

 and sharp, and are usually 

 curved. This is especially 

 the case in the Cat tribe; 

 in which there is also a very 

 remarkable provision for en- 

 abling the animal to project 

 them only when they are 

 required, keeping them drawn 

 in at other times. The last 

 phalangeal bone, to which 

 the claw is attached, has a 

 rotatory movement upon the 

 preceding one; this move- 

 ment is effected in one direc- 

 tion by a powerful muscle, 

 which draws the bone down- 

 wards and causes the claw to project ; whilst there is a ligament 

 composed of elastic fibrous tissue ( ANIM. PHYSIOL., 29), which 

 draws the bone in the other direction, and retracts the claw 

 within a kind of sheath. When the animal is walking, running, 

 or leaping, the claws are thus drawn in, without any exertion on 

 the part of the animal, by the simple elasticity of the ligament ; 

 and they are thus secured, either from receiving injury by wear 

 against the ground, or from impeding the movements of the 

 animal by becoming entangled in the inequalities of its surface, 

 or in the vegetation that covers it. In this state of the claws 

 the animal bears upon a number of soft cushions, one beneath 

 each toe ; which enable it to steal with noiseless steps upon its 

 prey, and thus, by surprising them, to vanquish animals whose 



FIG. 101. LEG AND CLAW OF LION. 



