178 JUNGLE ISLAND 



it looks even more like a mossback and is hard 

 to see. This one that we saw had a darker 

 pattern on its back, like a dead leaf, which would 

 camouflage it very well from below. The sloth 

 bestirs itself occasionally to eat green leaves, and 

 sometimes it is found asleep, curled up like a 

 bird's nest, in the top of a tall tree. 



Although the sloth seems like a collection of 

 misfits, he is suited well enough to the simple 

 life he leads, which would be stupid for a more 

 active animal. He possesses also the valuable 

 quality of being almost impossible to injure fatally 

 by ordinary methods. He does not have to move 

 out of the way of poisonous snakes, for snake 

 bites do not poison him. And for ordinary wounds 

 of any kind he cares as little as the lizard minds 

 losing his tail. 



The large animals found on Barro Colorado 

 are of the kinds found all through the American 

 rainy tropics. The northern line of this part of 

 the world is shown on the first map in the book, 

 running up into Mexico. A much greater share 

 of the warm rainy countries is in South America. 

 The Isthmus has served for a land bridge between 

 Central America and South America. The Canal 

 with its constant traffic will cut this bridge apart, 

 though it is too early to tell what effect this 

 will have on the large animals living on either 

 side. We shall have to wait and see if it makes 

 any difference. 



