2o8 EDENTATES. 



pottos among the lemurs, and it is then that they present the most striking 

 resemblance to a lichen-clad knot. They are found usually either in pairs or in 

 small family parties ; and are harmless and inoffensive in disposition. They are 

 most active in the dusk and at night ; and will then wander slowly for consider- 

 able distances through the forest. Their food consists exclusively of leaves, 

 young shoots, and fruits, the moisture contained in which renders drinking 

 unnecessary. Their favourite food is afforded by the large-leaved and milky 

 cecropia trees, which are so abundant in the South American forests ; and it 

 is said that they seldom desert a cecropia so long as it affords them nutriment. 



The sense of hearing in these animals seems but imperfectly developed ; and 

 their small, dull and reddish eyes do not appear capable of very acute vision. 

 Indeed, on first observing a sloth its eyes look so devoid of brightness as to give 

 the impression that the creature must be blind. But a single young is pro- 

 duced at a birth. When it first comes into the world the young sloth is fully 

 developed, having the body thickly clothed with hair, and the claws on the toes 

 of the same proportionate length as in the adult. With these claws it clings 

 fast to the long hair of its mother, clasping its arms around her neck. 



Sloths are capable of enduring deprivation from food for protracted periods, 

 and they are also remarkable for the severe bodily injuries they are capable of 

 sustaining, while they appear to be unaffected by doses of poison which would 

 immediately prove fatal to other animals of larger size. It is related that on one 

 occasion a three-toed sloth kept in captivity at Turin took no food for upwards of 

 a month, and appeared none the worse at the end of its long fast. All these 

 circumstances clearly point to the low organisation of these animals; it being a 

 well-known fact that reptiles exhibit a far greater tenacity of life than the higher 

 mammals. Indeed, as a rule, the lower we descend in the animal kingdom, the 

 greater becomes the power of sustaining injury. 



The Extixct Grouxd-Sloths. 

 Family Mega theriid^e. 



No account of the Edentates would be complete without some reference to the 

 gigantic ground-sloths which were formerly so abundant in South America, as it 

 is by their aid alone that we are able to comprehend the relationship of the true 

 sloths to the ant-eaters. The best known of these creatures is the megathere, 

 which rivalled the elephant in bulk ; while the mylodon and scelidothere were 

 somewhat smaller forms. They may be described as possessing the skulls and 

 teeth of sloths, and the back-bones, limbs, and tails of ant-eaters. The megathere 

 differs from most of the others in having the crowns of the teeth square and 

 divided into wedge-shaped transverse ridges, owing to the variation in the hardness 

 of their constituents ; but in most cases the teeth were subcylindrical, with depressed 

 centres. They agreed with the sloths iu having large and complete collar-bones ; 

 but, as we infer from the conformation of the lower jaw, they approximated to the 

 ant-eaters in the elongation of their tongues. The majority of the ground-sloths 

 were South American : but one species of megathere ranged into North America, 

 while an allied genus, Megalonyx, was apparently exclusively North American. 



