Still rarer, though if possible yet more formidable, is a small brown viper (_Echidna ocellata_), which infests the Peruvian forests. Its bite is said to be able to kill a strong man within two or three minutes. The Indian, when bitten by it, does not even attempt an antidote against the poison, but stoically bids adieu to his comrades, and lays himself down to die. The ill-famed wide-extended race of the rattlesnakes, which ranges from South Brazil to Canada, belongs exclusively to the New World. They prefer the more elevated, dry, and stony regions, where they lie coiled up in the thorny bushes, and only attack such animals as come too near their lair. Their bite is said to be able to kill a horse or an ox in ten or twelve minutes; but, fortunately, they are afraid of man, and will not venture to attack him unless provoked. When roused to anger they are, however, very formidable, as their fangs penetrate through the strongest boot. One of the most remarkable features of their organisation is a kind of rattle terminating the tail, and consisting of a number of pieces inserted into each other, all alike in shape and size, hollow, and of a thin, elastic, brittle substance, like that of which the scales are externally formed. When provoked, the strong and rapid vibratory motions imparted to the rattle produce a sound which has been compared to that of knife-grinding, but is never loud enough to be heard at any distance, and becomes almost inaudible in rainy weather. [Illustration: RATTLESNAKE.] Naturalists distinguish at least a dozen different species of rattlesnakes, the commonest of which are the Boaquira (_Crotalus horridus_), which frequents the warmest regions of South America, and the Durissus (_C. durissus_), which has chosen the United States for its principal home. The chief enemy of this serpent is the hog, whom it dreads so much that on seeing one it immediately loses all its courage, and instantly takes to flight. But the hog, who smells it from afar, draws nearer and nearer, his bristles erected with excitement, seizes it by the neck, and devours it with great complacency, though without touching the head. As the hog is the invariable companion of the settler in the backwoods, the rattlesnake everywhere disappears before the advance of man, and it is to be hoped that a century or two hence it will be ranked among the extinct animals. The American Indians often regale on the rattlesnake. When they find it asleep, they put a small forked stick over its neck, which they keep immovably fixed to the ground, giving the snake a stick to bite, and this they pull back several times with great force, until they perceive that the poison-fangs are torn out. They then cut off the head, skin the body, and cook it as we do eels. The flesh is said to be white and excellent.