MAMMALIA QUAUIiUMANA. 471 



comprehending the Monkey and the Lemur tribes, 

 which are characterized by having the inner toe 

 quite distinct from the others, like the human 

 thumb, and which appear, therefore, as if they had 

 four hands. 



The Quadrumana present the nearest approxi- 

 mation to the human structure : they are naturally 

 inhabitants of the forest, and their conformation is 

 adapted to the actions of climbing upon trees, of 

 grasping the branches, and of springing from the 

 one to the other, with precision and agility. It 

 is here that they are at home ; it is here that 

 they gather the food which is most suited to their 

 nature ; it is here that they engage in successful 

 combats with serpents and other enemies ; retain- 

 ing their positions in perfect security on the moving- 

 branches, or sportively swinging by their extremi- 

 ties in the air. Both the feet and the hands are 

 formed for this species of prehension ; and many 

 are farther provided with a strongly prehensile 

 tail, which is an instrument admirably adapted to 

 all these purposes. Hence the attitude most natural 

 to these animals is neither the horizontal one of 

 quadrupeds, nor the erect posture of man, but an 

 intermediate or semi-erect position. 



This view of the living habits of the quadru- 

 mana will afford the key to most of the peculia- 

 rities of structure they present to our observation. 

 The head, being no longer suspended at the end of 

 a horizontal, or recurved neck, is, in the usual atti- 

 tude of the animal, supported chiefly by the cer- 

 vical vertebrae. The greater developement of the 

 brain, and more especially of its posterior lobes, 

 creates a necessity for an extension of the occipital 



