CHAPTER VI 



THE FOOD OF ANIMALS— CARNIVOROUS AND INSECTI- 

 VOROUS REPTILES 



CROCODILES 



Reptiles exhibit many forms of adaptation to an animal diet. 

 We may fitly begin with the Crocodiles and their allies, which 

 are at the same time the most highly organized and the most 

 formidable members of the class (see vol. i, p. 21 ). 



The well-known Nile Crocodile (Crocodilus Niloticus) will 

 serve as an average illustration. The seizing organ is here 

 constituted by the powerful jaws, with their numerous strong, 

 pointed, and interlocking teeth, which, once having got a firm 

 grip, rarely leave go. Even a large Mammal, when caught, 

 struggles in vain, but is steadily drawn under water and drowned, 

 after which it is devoured by a series of tearing snaps. The 

 Crocodile itself might easily get choked during this drowning 

 process were there not some special provision to prevent it. This, 

 preventive arrangement consists in the extreme backward posi- 

 tion of the internal nostrils, and the upward projection of the 

 top of the windpipe into the hinder part of the nasal passages. 

 Thus the mouth can be kept more or less open under water 

 without any risk of suffocation. We are reminded here of a 

 similar contrivance among the Cetacea, the existence of which 

 is due to a similar reason. Although Crocodiles are capable 

 of fairly rapid progression on land, they are specially adapted tO' 

 swift movement in the water, the laterally-flattened tail acting 

 as the organ of propulsion. This powerful structure can also 

 be used as a flail, by the sudden use of which unwary animals- 

 standing close to the water's edge, as for the purpose of drinking, 

 are swept within the range of the jaws. Much, if not most of 

 the success of the Crocodile as a hunter, is due to his craftiness. 



Floating like a log in the water he is able to approach his prey 



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