The Biology of the Crocodilia 39 



then remain motionless as a statue. Such is the 

 average crocodile an active, vicious and, above 

 all, treacherous brute." Ditmars says again, in 

 the same book: "When the keepers of the reptile 

 house of the New York Zoological Park clean out 

 the big pool of the crocodilians, they actually walk 

 over the backs of some of the big 'gators, so tame 

 are these. They never become unduly familiar 

 with the crocodiles, finding it necessary to pen the 

 latter behind heavily barred gates and in the pro- 

 cess the men are often chased from the enclosure." 



In contrast to this ferocious aggressiveness in 

 captivity the American crocodile is said to be very 

 timid and retiring when in its native habitat. 



Young animals are greenish with black marking ; 

 as they become older they are of an olive color, 

 and old specimens are dull gray. 



THE ORINOCO CROCODILE, C. intermedius 



This is a species with a very narrow snout that is 

 not quite so large as the preceding. It is said to be 

 abundant in the Orinoco River and its tributaries. 



Besides the two above mentioned there is a 

 small species, C. rhombifera, found only in Cuba 

 and hence known as the Cuban crocodile. 



THE AFRICAN OR NILE CROCODILE, C. niloticus 



This well known and much feared species is 

 found throughout the continent of Africa, and is 



