4 TYPES OF ANIMAL LIFE 



dazzling sunshine, borne up on columns which tower 

 through the obscurity of the vast space beneath, wherein 

 a second growth of what would elsewhere seem noble 

 crees finds a congenial home. Beneath these, again, there 

 may yet be another similar but smaller growth, while 

 lycopods and a multitude of humbler herbs clothe the 

 .soil. Evidently, if adaptation to surrounding conditions 

 takes place anywhere among animals, special adaptations 

 to forest life may be looked for here ; and here they are 

 found. Many a bird and beast which elsewhere exists 

 in plains or in woods of relatively small extent, has here 

 its emphatically arboreal representative, as the fowl 

 seems to be represented by the curassow and the goose 

 by the horned screamer. For animals which cannot fly, 

 but have to pass their lives amid such an ocean of forest, 

 it is especially needful that they should be supplied with 

 all possible means of avoiding a fatal fall. 



Thus the sloth, which passes its life hanging beneath 

 the branches, has its hands and feet changed into what 

 seem mere hooks,which remain bent over when at rest and 

 need an effort to unclasp. By this means the animal 

 can sleep securely while hanging, back downward, within 

 its leafy bower. Monkeys, as we all know, have the feet 

 modified into prehensile organs acting like hands, the 

 great toe grasping powerf ully in opposition to the other 

 four. This modification wonderfully adapts them for 

 tree life. There is, however, one further possible 

 adaptation, and only one, and it is just that very adapta- 

 tion which is to be found in the monkeys of American 

 forests. It is an adaptation which supplies them with 

 what is practically a fifth hand. In the spider monkeys, 

 the woolly monkeys and the howling monkeys, the 

 under-surface of the terminal portion of the tail is 

 naked, so that it can be very closely applied to any 



