SPIDER MONKEYS 19 



would be so great that fatigue would soon oblige him to relin- 

 quish his hold. 



The thumb of a gibbon's hand, being useful neither for grasping 

 nor for climbing, is therefore quite small and unimportant. That 

 of the hinder foot, however, is very large and powerful, for in it 

 great strength of grasp is required. If our own feet were formed 

 like our hands we should be able to climb very much better than 

 we can now, although we could not walk so well upon level ground. 

 But the bodily frame of every animal is always most wonderfully 

 suited to the life which it has to lead; and as the gibbon lives 

 almost entirely in the trees, its feet are more formed for climbing 

 among the branches than for walking upon the ground, though it 

 walks more upright than any of the other apes. 



The gibbons are the smallest of these man-like apes, the largest 

 gibbons being barely over three feet, while most of them are 

 under two-and-a-half feet. 



SPIDER MONKEYS 



None of the gibbons inhabit any part of the American continent; 

 but their place in the New World is taken by another very inter- 

 esting group of " monkey acrobats ". These are usually known as 

 Spider Monkeys, because their long, slender limbs and hairy 

 bodies give them very much the appearance of overgrown spiders. 

 Unlike the gibbons, all the members of this group are furnished 

 with long prehensile tails — that is, tails that can be twisted tightly 

 round a branch or other object, and employed as a sort of 

 additional hand. 



When a spider monkey is climbing about in a tree, he never 

 seems to feel quite secure unless the tip of his tail is firmly grasp- 

 ing a branch. Occasionally, of course, he finds it necessary to 

 walk along a bough which has no smaller branches growing from 

 it, so that this "fifth hand", as it has often been styled, can find 

 no hold. Even in this case, however, it is not permitted to remain 

 idle, but is held over the back, curled into the shape of the letter 



