FAMILY TARDIGRADA ; SLOTHS. 275 



lies buried in the long wool which covers those parts, and is thus 

 protected during sleep from the myriads of insects which would 

 otherwise attack it. 



242. Although the Sloths might appear to be totally unpro- 

 vided with the means of defence, and liable to fall an easy prey 

 to their enemies, yet this is really very far from being the case ; 

 since their structure is no less adapted for their defence from 

 attacks, than it is for their peculiar dwelling-place and supply of 

 food. In the first place, their long shaggy hair defends them from 

 the insects, which in that climate are so troublesome ; its texture 

 is very peculiar, more resembling dry hay, or grass shrivelled 

 and withered by the sun, than the hair of ordinary quadrupeds ; 

 and its appearance so much resembles that of the bark and moss 

 of the branches on which the Sloth lives, as to prevent the animal 

 from being easily detected, except when it moves. Its usual 

 position places it above the reach of ordinary carnivorous quad- 

 rupeds ; but its powerful claws, and the peculiarly enduring 

 strength of its long arms, make them very efficient weapons of 

 defence. When attacked on the ground, the Sloth throws himself 

 on his back, fixes his claws on his adversary, and grasps him 

 with enormous power ; in this manner he has been known to 

 strangle a dog, holding him all the while at arm's length ; and 

 in the same mode he grapples with snakes of large size, which, 

 in his natural residence, are probably his chief enemies. 



243. The teeth of the Sloths are not fitted to grind down 

 their food, on account of the absence of the ridges of hard enamel 

 which we find in the molar teeth of other herbivorous quad- 

 rupeds ; but they are adapted merely to bruise it, or break down 

 the tender structure of the buds and leaves. This deficiency is 

 compensated by the complex structure of the stomach, which 

 somewhat resembles that of the Ruminants ( 98). In the Two- 

 toed Sloth, the stomach is almost completely divided into two 

 cavities, of which the first is again partially subdivided into 

 three others ; four chambers are thus formed, which are obviously 

 analogous to the four stomachs of the Ruminantia ; but there is no 

 reason to think that anything like actual rumination takes place. 



244. We next proceed to a family entirely consisting of huge 

 fossil animals, which have entirely passed from the surface of the 



T2 



