ORDER SAURIA. 185 



almost ominous pace concurs to the general effect which they 

 produce on the imagination. Yet they are ferocious only 

 when pressed by necessity, and a crocodile satiated with food 

 is an enemy whom the weakest have no cause to fear. This 

 was well known to the ancients, and has been long ago re- 

 marked by Aristotle. The ancients believed, and the modems 

 have repeated the assertion, that the upper jaw of the croco- 

 dile alone was moveable. But it has been for some time 

 clearly ascertained that this is an error, and that in the 

 crocodile, as in all other animals, it is the lower jaw only 

 which is in this predicament. The origin of this opinion is, 

 that the crocodiles having the centre of movement in the jaws, 

 situated beyond the cranium, they cannot open them without 

 raising the head. From the same cause they are unable to 

 masticate their food : they can only break or crush, and 

 then swallow it. 



With the exception of the summit of the head, the entire 

 body of the crocodile is covered with scales. The crocodiles 

 can therefore only be wounded in those parts where the scales 

 are separated, that is, at the junction of the thighs with the 

 body, in the eyes, or mouth. 



The brain of the crocodile is remarkably small, the oeso- 

 phagus very ample, and capable of great dilatation. They 

 have no bladder, and their organs of generation are internal, 

 near the anus ; above the jaws, two glands are observable, 

 which contain an oily matter of a strong musky odour. 



Of the osteology of the crocodiles we have already treated 

 pretty much at length, in our account of the fossil remains, 

 and shall therefore say nothing about it in this place. 



Spring is the period in which the sexes seek each other. 

 Concerning all that has relation to the reproduction of these 

 animals, little is known with any degree of certainty. The 

 crocodiles lay two or three times in the year, but at short 

 intervals, about twenty eggs at least, and sometimes many 



