Читать книгу The Circle of Knowledge: A Classified, Simplified, Visualized Book of Answers - Various - Страница 276

These inhabitants of the rivers and estuaries of tropical regions are somewhat lizard-like in appearance, but in structure they are in many ways much more specialized. They have a scaly, tough skin on the back, four powerful feet, and a long tail. They live chiefly in the water, and only go to the banks to bask in the sun. The jaws are armed with powerful interlocking teeth, which constitute a deadly trap. The valvular nostrils are so situated that the animal can drift along with most of its body submerged, and at the same time breathe quite easily.

Alligator (Alligator mississippiensis) is found in the southern states of North America. It is as voracious as it is bloodthirsty. Should it perceive an unfortunate mammal drinking or browsing on the edge of the bank, it sinks below the surface, and rapidly swims toward the victim by strokes of its powerful, flattened tail. Then comes a sudden snap, aided, perhaps, by a lash of the tail; should the attempt prove successful, the prey is held under water till it is drowned, if too large to be forthwith swallowed. No bullet will pierce the hide on its back. It deposits its eggs in a kind of nest, which it builds with grass and mud on the banks, and defends with great fierceness. It deposits about one hundred eggs in this nest. The alligator is captured in various ways, but there is danger in hunting it.

Crocodile (Procœlia) is found in both hemispheres, but especially in Africa; they swarm on the Upper Nile. The crocodile of the Nile is a well-known species, not now found farther north than Thebes, but occurring abundantly farther south and east. Some two or three score of eggs, with delicate, rough, limy shells, about the size of those of geese, are laid in sandy cavities in the bank. The crocodile is now hunted for the perfume of its musk-glands, and also for its skin and fat.

The alligators have a covering of horny plates, and terrible jaws and teeth. These teeth are frequently renewed, new ones forming in place of those worn out. Alligators are, in this respect, more fortunate than human beings. In America alligators are protected part of the year, because they kill things which damage the crops.