132 TEXT-BOOK OF ZOOLOGY 



ously. In recent years numerous whaling-stations have been established 

 on the northern coasts of Norway and Eussia, whither the animals killed 

 in the neighbourhood are dragged to be cut up. Here the flesh and 

 bones also are converted into a valuable manure. 



ORDER XII. : EDENTATES (EDENTATA). 



TEETH either absent or reduced, destitute of enamel, and without 

 roots. The digits carry long and powerful nails for scraping, or sickle- 

 shaped claws for digging and grasping. 



The Three-Toed Sloth, or Ai (Bradypus tridactylus). 



This animal is an inhabitant of the vast primeval forests of Brazil. 

 Its habits are strictly arboreal. (Compare orang-utan.) By means of 

 its long, sickle- shaped claws it climbs up trees, or hangs for days long 

 on the branches, with its back turned downwards, without appearing to 

 get tired. The articulations of the fore and hind limbs are far apart ; 

 in this way the animal is enabled to grasp branches at a considerable 

 distance. The bones of the fore-limb are very movable, and the soles 

 of the feet turned inward, an arrangement which greatly facilitates 

 climbing. On the ground, however, the sloth is completely helpless; 

 nor does it, except rarely, descend to the ground, since its food, which is 

 always moist, provides it with sufficient water. The neck is extremely 

 movable, allowing the animal, in spite of its suspended position while 

 climbing, not only to look straight in front of it, but also to turn its head 

 right round towards its back. The two first thoracic vertebrae have no 

 ribs, and thus the seven cervical vertebrae which all other mammals 

 possess are increased to nine. It is able to support itself on, and to 

 progress along, branches of extreme thinness a fact which protects 

 it from most of the climbing carnivora. Against the larger birds of 

 prey (eagle) it is protected by the colour of its coat, which consists of 

 long, dry, coarse hairs. An animal suspended at rest from a branch or 

 sleeping in the fork of a tree bears an exact resemblance to a large 

 cushion of dry moss or a bundle of lichens. In correspondence with its 

 usual suspended position, the hairs are directed from the belly towards 

 the back, so as to allow the rain to drain off. In spite of the slowness of 

 its movements, it can always find food in sufficiency, the primeval forest 

 almost placing it within its mouth. 



Related Species. 



The relatives of the peculiar sloths are animals no less peculiar. One 

 of them is the Ant-eater (Myrmecopliaga jubata), which lives in the 



