1518 THE STORY OF THE UNIVERSE 



in order that inequalities may always exist on the 

 crown of these teeth, it is also requisite that their 

 substance be composed of parts of unequal hardness, 

 so that one may wear away faster than others. 



Hoofed animals are necessarily herbivorous, and 

 have flat-crowned grinders, inasmuch as their feet 

 preclude the possibility of their seizing a living prey. 



Animalswith unguiculated fingers were susceptible 

 of more variety; their food is of all kinds, and in- 

 dependently of the form of their grinders, they differ 

 greatly from each other in the pliability and delicacy 

 of their fingers. There is one character with re- 

 spect to this which has immense influence on their 

 dexterity and greatly multiplies its powers; it is the 

 faculty of opposing the thumb to the finger for the 

 purpose of seizing minute objects, constituting what 

 is properly called a hand, a faculty which is carried 

 to its highest perfection in man, in whom the whole 

 anterior extremity is free and capable of prehension. 



These various combinations which strictly de- 

 termine the nature of the different mammalia have 

 given rise to the following orders: 



Among the unguiculated animals, the first is Man, 

 who, in addition to privileges of other descriptions, 

 possesses hands at the anterior extremities only, the 

 posterior being designed to support him in an erect 

 position. 



In the order next to man, that of the Quadrumana, 

 we find hands at the four extremities. 



In another order, that of the Carnivora, the thumb 

 is not free, and can not be opposed to the anterior 

 extremities. 



