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 Zodélogical 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 
