Quite near to the lion house, on the other side, is the reptile house, where live snakes, crocodiles, and lizards, and all sorts of curious animals. The most interesting are the enormous snakes, called boa-constrictors, with bodies nearly as thick as a child's, and many yards in length. They are not in cages, but in glass houses, like glass boxes. The glass is very thick and strong, and the snake does not dash himself against it to get out. He would not take the trouble to do that, for he moves slowly, and when you see him at the Zoo you would think him very lazy. There he lies, with his oily body, covered with little scales, hanging round the branch of a dead tree which has been put into his house, or perhaps lying coiled up on the gravel floor in rings and rings, so beautifully neat that you wonder how he can take the trouble to fold himself up so nicely before he goes to sleep. He certainly would not get crumpled if he lay anyhow, as your clothes would get crumpled if you did not fold them up. Watch him very closely. You can see he breathes, and perhaps he glances up and winks with one eye, or darts out a wicked little tongue. How can a creature like that, so big and so slow, ever get any food? Well, he can go fast enough at times, and he does not often want a meal, because he eats so much at one time that it lasts him for many days. He writhes his great body along the ground in the thick woods of his native country, and lies so still that you might tread on him without seeing him. He lives in Brazil and other parts of South America. Perhaps a young deer comes down to drink, all unconscious of the hideous beast lying in watch. He stoops his pretty head, then, with a writhing movement, the boa is upon him. The deer struggles frantically, but the great folds of the snake close ever tighter and tighter round him with a strength that breaks his delicate bones and squeezes the life out of him. When the animal, crushed and breathless, ceases to struggle, the boa opens his gaping mouth, and bit by bit the whole animal--it may be still palpitating--is forced into that awful throat. The snake cannot tear his prey; he has no hands or feet, no claws or hoofs. He can only swallow it whole. It would seem impossible sometimes that he could get that mass into his comparatively narrow throat; but his muscles are elastic. He stops half-way through his horrid meal and lies still to rest, then another swallow and another. In the meantime, his teeth, like little sharp saws bent backwards, covering all the roof of his mouth as well as the jaws, are firmly fixed into the victim, so that it cannot draw back. When the disgusting meal is done the great snake lies helpless and swollen, and has to wait until his food is digested before he can get about comfortably.