Page:Popular Science Monthly Volume 55.djvu/209

Rh bringing the business end, neck and all, a few feet nearer; the bead "points," like a leveled rifle, then darts forward with electric swiftness, guided by an unerring instinct for the selection of the least-protected parts of the body.

And the vindictive brute is ready to repeat its bite. For a moment it rears back, trembling with excitement, and, if felled by a blow of its victim's stick, will snap away savagely at stumps and stones, or even, like a wounded panther, at its own body.

A very curious adaptation of means to ends in the modification of the virus is its swiftly fatal effect on birds. A stricken child, though half crazed with fear, may run a distance of three miles before paralysis begins to impede its motions; a squirrel will escape to its nest in the top of the tree, only to come forth again and topple down



in its delirium; but a bird drops as if he had swallowed a dose of prussic acid. Serpent virus is specifically a bird poison; in other words, it acts instantaneously in cases where a few moments' delay would defeat the purpose of the snap bite. Wounded rodents will not run very far and can be relied upon to come out of their holes; but a bitten bird, unless promptly paralyzed, would fly out of sight and drop in distant thickets, beyond the ken of its destroyer. And of all bird-killing reptiles the fer-de-lance is the most destructive. The Spaniards have varied its bill of fare by importing the wherewithal of an occasional rabbit stew, but during the preceding ages it had to subsist on poultry, like a popular circuit preacher—the hutia rat having developed a talent for avoiding its haunts.

The alleged horror naturalis of serpents is perhaps not more deep-rooted than the aversion to cats; at all events, the West Indians have overcome it sufficiently to prefer rat-killing snakes to tabbies.