xv INTRODUCTION. 



sitiveness of their fingers. When they possess a thumb, which 

 is opposable to the finger for the purpose of seizing minute 

 objects, the power of the hand is greatly increased, and has 

 an immense influence on their dexterity. The opposable power 

 of the thumb exists in the highest perfection in the human 

 hand, the whole of which is free and capable of prehension." 

 It is upon these various combinations, which strictly determine 

 the nature of the different mammals, that Cuvier has divided 

 the whole class of MAMMALIA into the following ORDERS, 

 namely, 



I. BIMANA, consisting of man only, who, in addition to 

 his peculiar privileges, possesses hands at the extremities of 

 his arms alone, the extremities of his legs being designed 

 merely for his support in an erect position. 



II. QUADRUMANA, having hands at all four extremities. 



III. CARNARIA, with the thumb not free, and it cannot 

 be opposed to the anterior extremities. 



*,u* Each of the preceding orders has the three sorts of 

 teeth ; namely, molars, or grinders, canines, and 

 incisors, or cutting teeth. 



IV. RODENTIA, with toes differing but little from those 

 of the third Order, but this has no canine teeth, and the 

 incisors are placed in front of the mouth, and adapted to a 

 very peculiar sort of manducation. 



V. EDENTATA, with toes much cramped, and deeply sunk 

 in large nails, which are generally curved ; they have no incisor 

 teeth, and in some the canine teeth disappear, while others have 

 none of any kind. 



VI. MARSUPIALIA, consists of animals possessing abdo- 



