Here, then, we seem to be drifting along the road to snake-life, but we must halt and travel first in another direction, upwards to a higher group of animals, which may almost be called gigantic flesh-eating lizards, though they are far more formidable and highly-organised creatures. These are the Crocodiles, and no one looking at them can doubt for a moment that they at least are well armed, so as to have an easy time of it without much exertion. Huge creatures, often more than twenty feet long, with enormous heads and wide-opening mouths, holding more than thirty teeth in each jaw, they look formidable indeed as they drag their heavy bodies along the muddy banks of the Nile, their legs not being strong enough to lift them from the ground. Their whole body is covered with strong horny shields, and under these shields, on the back, are thick bony plates, which will turn even a bullet aside, and quite protect the crocodile from the fangs of wild beasts. Their eyelids are thick and strong, and they have a third skin which they can draw over the eye sideways like birds; their ears, too, have flaps to cover them, and their teeth are stronger and more perfect than any we have yet seen, for they are set in sockets, and new ones grow up inside the lower part of the old ones as they are broken or worn away. [Illustration: Fig. 25. The Nile Crocodile.--(_Tristram._)] But it is in the water that we see them in their full strength; there they swim with their webbed feet and strokes of their powerful tail, and feed upon the fishes and water animals--monarchs of all they survey. Nor is the crocodile content with mere fish-diet. Often he will lie with his nostrils just above the water and wait till some animal--it may be a goat, or a hog, or even a good-sized calf--comes to drink, then he will come up slowly towards it, seize it in his formidable jaws, or sometimes strike it with his powerful tail, and drag it under water to drown. For he himself can shut down his eyelids and the flaps over his ears, and he has a valve in the back of his throat which he can close, and prevent the water rushing down his open mouth; and after a while he rises slowly till his nostrils are just above the water, and he can breathe freely while his victim is drowning, because his nose-holes are very far back behind the valve. Then when it is dead he brings it to shore to tear it to pieces and eat it.