"When I was a very young man," the professor explained, embarrassed, "I attained a certain amount of proficiency with the bowie-knife."

"I'll say you did!" exclaimed Jud, as he worked the knife out of the tough bark. "Any cannibal that comes within fifty yards of this party is liable to be chopped an' stabbed an' broken an' shot—to say nothin' of Hen's machete at close quarters."

Pinto had watched these various performances in silence.

"This evening," he said at last, "I show you a gun that kills without any noise."

Borrowing Joe's hatchet, he disappeared into the woods, to come back half an hour later with a nine-foot stick of some hard, hollow, light wood about an inch in diameter, straight as an arrow, and with a center of soft pith. Laying this down on a hard stump, Pinto, with the utmost care, split the whole length into halves. Then, fumbling in his belt he pulled from it one of the sharp teeth of the paca, that curious reddish rodent which is half-way in size and appearance between a hog and a hare and which is equally at home on land and in water, and whose two-inch cutting-teeth are among the favorite ready-made tools of all South American Indians. With one of these Pinto carefully hollowed out each section of the stick, smoothing and polishing the concave surface until it was like glass. Then, fitting the two halves together, he wound them spirally with a long strip of tape which he made from the tough, supple wood of a climbing palm, waxed with the black wax of the stingless bees. When it was finished he had a light, hollow tube about nine feet long. At one end, which he tapered slightly, he fixed, upright, the tiny tooth of a mouse, which he pressed down until only a fleck of shining ivory showed as a sight above the black surface of the tube. At the other end he fitted in a cup-shaped mouthpiece, chiseled out of a bit of light, seasoned wood.

By noon it was finished, and Jud and the boys saw for the first time the deadly blow-gun of the Mundurucu Indians. For arrows, Pinto cut tiny strips from the flinty leaf-stalks of palm-leaves. These he scraped until the end of each was as sharp as a needle. Then he feathered them with little oval masses of silk from the seed-vessels of silk-cotton trees, whose silk is much fluffier and only about half the weight of ordinary cotton. In a short time he had made a couple of dozen of these arrows, each one of which fitted exactly to the bore of the blow-gun, and also fashioned for himself a quiver of plaited grasses, which he wore suspended from his shoulder with a strip of the palm tape.

Late in the afternoon he made another trip into the forest, returning with a mass of bark scraped from a tree called by the Indians mavacure, but which the white settlers in South America have named the poison tree. This bark he wet in the river, and then pounded it between two stones into a mass of yellowish fibers, which he placed in a funnel made of a plantain-leaf. Under this he set one of the aluminum cups which each of the party carried fastened to his belt. This done, he poured in cold water and let the mass drip until the cup was full of a yellow liquid, which he heated over a slow fire. When it thickened he poured in some of the milky juice of another near-by tree, which turned the mixture black. When it had boiled down to a thick gummy mass, Pinto wrapped it up carefully in a palm-leaf, after first dipping every one of his arrows into the black compound.

So ended the making of the famous urari arrow-poison, which few white men indeed have ever seen brewed. When it was safely put away, Pinto carefully fitted one of the tiny arrows into the mouthpiece and raised the blow-gun to his mouth, holding it with both hands touching each other just beyond the mouthpiece, instead of extending his left arm, as a white man would hold a gun. Even as he raised the long tube, there came a crashing through the near-by trees, and the party looked up to see a strange sight. Rushing along the branches came a pale greenish-gray lizard, marked on the sides with black bars and fully six feet in length. Along its back ran a crest of erect spines. Even as its long compressed tail whisked through the foilage, a reddish animal, which resembled a lanky raccoon, sprang after it like a squirrel, following hard on its trail.

"It's an' ol' coati chasin' a big iguana," muttered Hen, as the pair went by. "They're both mighty fine eatin'."

At first, the pursued and the pursuer seemed equally matched in speed. Little by little, the rapid bounds of the mammal overtook the swift glides of the reptile, and in a tree-top some fifty yards away the iguana turned at bay. In spite of its size and the threatening, horrible appearance of its uplifted spines, the coati made short work of it, worrying it like a dog, and finally breaking its spine. Even as its long bulk hung lifeless from the powerful jaws of the animal, Pinto drew a deep breath and, sighting his long tube steadily toward the distant animal, drove his breath through the mouthpiece with all his force. There followed a startling pop, and a white speck flashed through the air toward the coati. A second later, the latter, still holding the dead iguana, gave a spring as if struck by something, and started off again through the tree-tops, the great body of the dead lizard trailing behind. Suddenly the coati began to go slower and slower and then stopped short. Its head drooped. First one paw and then another relaxed, until, with a thud, the coati and iguana struck the ground together both stone-dead. The boys rushed over and found Pinto's tiny, deadly arrow embedded deep in the coati's side. Less than a minute had passed since it had been struck, but the deadly urari had done its work. Fortunately, this poison does not impair the food value of game, and later on, over a bed of coals, Hen made good his words about their eating qualities. The coati tasted like roast 'possum, while the flesh of the giant lizard was as white and tender as chicken.