THE SLOTH 251 



Many an arboreal animal is furnished with a prehen- 

 sile tail, but the tail of the sloth is quite rudimentary. 

 Being thus deprived of one mode of prehension, it is 

 necessary that its other means of clinging should be all 

 the more trustworthy. And nothing could be more 

 trustworthy than those of the sloth, which consist 

 only of its hands and feet, each one of which is so 

 modified as to be, practically, but a somewhat movable 

 hook. This is due to the fact that the fingers and toes 

 of each hand and foot are so closely bound together 

 that they cannot be separated ; while each finger and 

 toe is furnished with an enormously long and very 

 strong nail greatly curved. When at rest, the hands 

 and feet are so bent that each thus forms a strong 

 hook, and it requires an effort on the part of the animal 

 to unhook either a hand or foot from the branch it 

 clasps. Thus it is that the sloth can sleep suspended 

 from a branch, and remain so after death. But the fore 

 paws can grasp and carry to the mouth, fruits, twigs with 

 leaves or other objects, so that these paws do answer the 

 purpose of hands in spite of their fingers being so closely 

 bound together. 



We have hitherto spoken of " the sloth," as if there 

 was but one kind. There are however several kinds 

 which form two distinct groups or " genera." The first 

 genus contains the species known as the unau, or two- 

 toed sloth, because it has only two fingers, fully developed 

 and with long claws, to each hand ; these two fingers 

 answer to the index and middle fingers of the human 

 hand. In captivity, the unau will eat bread and milk, 

 vegetables and fruits, either cooked or raw. Its voice 

 has been compared to the bleat of a sheep, but is seldom 

 heard. It will also snort violently when seized. 



The sloths are very exceptional with respect to the 



