MONKEYS. 



437 



tion of their throats, are gifted with voices of tremendous power and volume 

 Their howling, as travellers tell us, may be heard for half a league around! 

 It is more especially at sunrise or sunset, or on the approach of a storm that 

 they make the forest re-echo with their frightful cries, and sometimes,' as it 

 would seem, they have recourse to this howling to drive away their enemies. 

 These monkeys are very common in the great forests of Brazil. 



FIG. 483. HOWLING MONKEY. 



The Spider Monkeys (A teles]* have the thumbs on their fore hands 

 either very minute or entirely wanting. Exclusively arboreal in their habits, 

 the Spider Monkeys move on the ground with a vacillating gait, dragging 

 themselves along by means of their long fore arms, which they use like 

 crutches, the fist being half closed ; or they walk in a crawling position, 

 sustaining themselves on their hind feet only, and balanced by their long 

 arms, and tail extended ready to seize any object which may help progression. 

 But among the branches of the trees their agility is almost equal to that of a 

 bird : the sensitive tip of the long tail lays hold of a bough with the facility 

 and security of a fifth hand, while its grasp is sufficiently powerful to sustain 

 the weight of the body as it swings. 



The Monkeys of the eastern hemisphere differ from the Ameri- 

 can monkeys in their teeth, which are only thirty-two in mumber. 

 Their nostrils are placed close together, separated only by a nar- 

 row partition, and in many species the tail is entirely wanting. 

 They may be divided in accordance with the following table : 



, ateles, imperfect in allusion to their having only rudimentary thumbs. 



