“All serpents dart back and forth between their lips, with extreme rapidity, something that looks like a black thread, of great flexibility and ending in a fork. Many persons believe this to be the reptile’s weapon, the sting, as they call it, whereas in reality it is nothing but the tongue—a quite inoffensive tongue, which the creature uses for catching insects to feed upon, and also for expressing in its own peculiar fashion the passions that agitate it. This last it does by shooting the tongue swiftly in and out between the lips. All serpents without exception have a tongue, but in our country it is only the viper that possesses the terrible apparatus for injecting venom. “This apparatus is composed, first, of two fangs or long, sharp teeth, situated in the upper jaw. Unlike ordinary teeth, these fangs are not fixed firmly in their sockets, but can at the creature’s will stand up for attack or lie down in a groove of the gum and remain there as harmless as a stiletto in its sheath. In this way the viper runs no risk of wounding itself. The fangs are hollow and pierced near the point with a very small opening through which the venom is discharged into the wound they give. Finally, at the base of each fang is a small pocket or sac filled with a venomous liquid. It is to all appearance a perfectly harmless liquid, odorless and tasteless, so that you would take it for nothing but water. When the viper strikes with its fangs, the venom sac discharges a drop of its contents into the tiny channel perforating the fang, and the liquid is injected into the wound. It is by mixing with the blood that the venom produces its terrifying effects.” “I remember all that very well,” said Jules, “and also what you said must be done to prevent the mixing of the venom with the blood in general that circulates through the body.” “And I also told you that the viper haunts by preference warm, rocky hills; it lurks under stones and in underbrush. In color it is brown or reddish, with a dark zigzag stripe along the back and a row of spots on each side, each spot fitting into one of the angles made by the zigzag stripe. Its stomach is slate-color and its head rather triangular in shape, being broader than the neck and running to a blunt point at the mouth. The viper is timid by nature and attacks man only in self-defense. Its movements are abrupt, irregular, and sluggish.” “What does it live on?” Jules inquired. “Does it eat nothing but little insects that it can catch with its tongue?”