Page:Natural History, Reptiles.djvu/63

Rh wanting, the teeth are visible when the mouth is closed; hence the animal, even when tranquil, seems grinning with rage. A similar expression is communicated to the visage from the eyes, which are placed obliquely near each other, and have a peculiarly fiery glare.

The compressed and dentelated tail, though from its length and weight it impedes the motions of these animals on the land, is yet an organ of the utmost importance to them in the water, where it is a most powerful instrument of progression, and influences their aquatic habits much more than their webbed hind feet. The latter are indeed used, when the animal is paddling with a slow and gentle action; but in sudden and swift motion, as in escaping from an object of alarm, or in energetic pursuit of prey, alternate strokes with the tail upon the element give the powerful impulse. On land, also, the Crocodile is said to use this organ as an efficient weapon of offence, dashing it from side to side with swift contortions, when its weight, its hard rough surface, and especially its saw-like crests, render its strokes eminently formidable. Like the Turtles, the Crocodiles lay their eggs in the sand, and leave them to be hatched by the heat of the sun. The general number is from eighty to a hundred: their size is about that of a goose's egg, but their form is more oblong.

When we consider the vast bulk of the adult animal, we may affirm that no creature exhibits so great a disproportion between its youth and age. The eggs are covered with a hard calcareous shell, like that of birds' eggs, but more shining, harder, and more brittle.