THE TROPICAL FOREST 111 



to permit them to pass from one tree to another shows 

 that their natural habitat is the dense forests where 

 tree is bound to tree by lianes. 



Among the special features we may note the nature 

 of the coat, the individual hairs having a fluted surface, 

 on which algae lodge, and so give the animals the 

 appearance of a Hchen-covered branch. The fingers 

 are converted into mere hooks, the tail is a stump, 

 a common feature in such arboreal animals as have 

 not prehensile tails, or do not require to use the tail 

 as a balancing organ after the fashion of squirrels and 

 tree-shrews (cf. bears, anthropoid apes, &c.). We have 

 already spoken of the elongation of the foreUmbs in the 

 sloths (p. 95) . The food consists of leaves and fruits and 

 the animals do not drink. The usual position is hang- 

 ing back downwards from the branches of trees, and the 

 animals sleep roUed up in a ball with the head tucked ^ 

 between the arms. Like many helpless forms they are 

 active only at night (see Fig. 32). 



The South American ant-eaters are also forest animals, 

 the large form called Myrmecophaga jvhata being strictly 

 terrestrial, while the little two-toed ant-eater (Cyclo- 

 turus didactylus) is arboreal, and except that it has 

 a prehensile tail and Hves upon insects, has a curious 

 adaptive resemblance to a sloth, both in the struc- 

 ture of its limbs and in appearance. The hairy ant- 

 eaters of South America are replaced in India and 

 Africa by the scaly ant-eaters or pangohns (Manis), but 

 though some of these are partially arboreal, most are 

 found in rocky country, where they burrow in the 

 ground. 



Not a few of the marsupials have acquired arboreal 

 habits. Thus the tropical forests of New Guinea and 

 Queensland are inhabited by tree kangaroos, which have 



