NOTE-BOOK OF A NATURALIST. 333 



as Providence, for the preservation, or to prevent the extinction of 

 defenceless creatures, hath, in many instances, restrained the 

 devouring appetites of voracious animals by some impediment or 

 other, so this destructive monster, by the close connexion of the 

 joints of his vertebrae, can neither swim nor run any other ways 

 than straightforward, and is consequently disabled from turning 

 with that agility requisite to catch his prey by pursuit. Therefore 

 the} do it by surprise, in the water as well as by land ; for effecting 

 of which Nature seems, in some measure, to have recompensed 

 their want of agility, by giving them a power of deceiving and 

 catching their prey, by a sagacity peculiar to them, as well as by 

 the outer form and colour of their body — which on land resembles 

 an old dirty log or tree ; and, in the water, frequently lies floating 

 on the surface, and there has the like appearance, — by which, and 

 his silent artifice, fish, fowl, turtle, and all other animals, are 

 deceived, suddenly catched, and devoured. 



Catesby also mentions their habit of swallowing stones 

 and other hard substances, not, as he thinks, to help 

 digestion, but to distend and prevent the contraction of 

 their intestines when they are empty. In the greater 

 number of many which he opened, nothing appeared but 

 chumps of light wood and pieces of pine-tree coal, some 

 of which weighed eight pounds, and were reduced and 

 worn so smooth from their original angular roughness, 

 that they seemed to have remained there many months. 



Dr. Buckland, in his Bridgeivater Treatise, well ob- 

 serves, that in the living subgenera of the crocodilian 

 family we see the elongated and slender beak of the 

 gavial constructed for feeding on fishes ; whilst the 

 shorter and stronger snout of the broad-nosed crocodiles 

 and alligators gives them the power of seizing and 

 devouring quadrupeds that come to the banks of rivers 

 in hot countries to drink. As there were scarcely any 

 mammalia during the secondary periods, while the waters 

 were abundant, we might, a 'priori, expect, he remarks, 

 that if any crocodilian forms then existed, they would 

 most nearly resemble the modern gavial. Accordingly, 

 those genera only which have elongated beaks have been 



