BONES AND JOINTS OF THE EXTREMITIES 49 



The motion limited to flection and extension 

 of the foot of a hoofed animal implies the absence 

 of a collar bone and a restrained motion in the 

 shoulder joint ; and thus the naturalist, from the 

 specimen in his hand, has got a perfect notion 

 of all the bones of the anterior extremity ! 

 The motions of the extremities imply a condition 

 of the spine which unites them. Each bone of 

 the spine will have that form which permits the 

 bounding of the stag, or the galloping of the 

 horse, but it will not have that form of joining 

 which admits the turning or writhing of the 

 spine, as in the leopard or the tiger. 



And now he comes to the head : the teeth of 

 a carnivorous animal, he says, would be useless 

 to rend prey, unless there were claws to hold it, 

 and a mobility of the extremities like the hand, 

 to grasp it. He considers, therefore, that the 

 teeth must have been for bruising herbs, and the 

 back teeth for grinding. The socketing of these 

 teeth in the jaw gives a peculiar form to these 

 bones, and the muscles which move them are also 

 peculiar ; in short, he forms a conception of the 

 shape of the skull. From this point he may set 

 out anew, for by the form of the teeth, he ascer- 

 tains the nature of the stomach, the length of the 

 intestines, and all the peculiarities which mark a 

 vegetable feeder. 



Thus the whole parts of the animal system are 



