480 THE TROPICAL WORLD. 



travel at a good-round pace when he has branches to cling to, 

 there is nothing to prevent him making a considerable way 

 before the sun sinks, and the wind goes down. 



During night, and while reposing in the daytime, the sloth 

 constantly remains suspended by his feet, for his anatomy is 

 such that he can feel comfortable in no other position. In this 

 manner he will rest for hours together, expressing his satis- 

 faction by a kind of purring, and from time to time his dismal 

 voice may be heard resounding through the forest, and awaken- 

 ing at a distance a similar melancholy cry. 



The colour of the sloth's hair so strongly resembles the hue 

 of the moss which grows on the trees, that the European finds 

 it very difficult to make him out when he is at rest, and even 

 the falcon-eyed Indian, accustomed from his earliest infancy to 

 note the slightest signs of forest life, is hardly able to distin- 

 guish him from the branches to which he clings. This no 

 doubt serves him as a protection against the attacks of many 

 enemies ; but, far from being helpless, his powerful claws and 

 the peculiarly enduring strength of his long arms, make very 

 efficient weapons of defence against the large tree snakes that 

 may be tempted to make a meal of him. 



The sloth possesses a remarkable tenacity of life, and with- 

 stands the dreadful effects of the wourali poison of the Macushi 

 Indians longer than any other animal. Schomburgk slightly 

 scratched a sloth in the upper lip, and rubbed a minimum of the 

 venom in the wound, which did not even emit a drop of blood ; 

 he then carried the animal to a tree, which it began to climb, 

 but after having reached a height of about twelve feet, it sud- 

 denly stopped, and swinging its head about from side to side, 

 as if uncertain which way to go, tried to continue its ascent, 

 which, however, it was unable to accomplish. First it let go 

 one of its fore-feet, then the other, and remained attached with 

 its hind-legs to the tree until, these also losing their power, it 

 fell to the ground, where, without any of the convulsive motions 

 or the oppressive breathing which generally mark the effect of 

 the wourali, it expired in the thirteenth minute after the poison 

 had been administered. 



The sloths attain a length of about two feet and a half, and 

 form two genera — the Unaus. with two-toed fore-feet and 



