War is their only object lesson, so quite naturally their only preëminence is in the art of killing. The chief cause of war is stealing of women; some are worth as much as a hatchet, some only the price of a knife. In times of fighting the savages howl through a giant reed in blood-curdling discord. They shoot with parrot-feathered cactus-arrows dipped in famous poisons, or thrust through an enemy with a _macana_--a wooden sword as sharp as steel--or fell him with a club of wood like iron. Then they make drums of his skin to serve as warning to his friends. They protect themselves with a shield of creeping plants interwoven, covered with a tapir skin and edged with the feathers of parrots. The only amicable exchanges between tribes are the poisons done up in reeds into which they will dip the arrows used each against the other. Some poisons, made by women and old men, can kill an animal without injuring his flesh for the use of man. Some make him merely wither away. Some do not take effect until three days after the wound is inflicted. The whole history of man, beginning with the Stone Age, could be studied among the wild tribes of Amazonian Peru. The largest tribe numbers nearly twenty-five thousand, many but a few families, and one tribe has now not a single member left. Differing each from the other, they are similar only in that they all represent the first steps of human development. A savage of the jungle perforates his face to insert feathers and shells; he gouges it with sharp flints and rubs in indelible color. He slashes his lips both within and without and stretches his ear-lobes as far as the shoulder. Then he inserts knobs of _chonta_-palm wood. He paints his face yellow and suspends a red bean from his nose. Or he paints his face in the four quarters, blue, yellow, red, and black, and dyes his hair red with _achote_, his body orange with _armatto_, staining it in design with dark juices. The Prios color their teeth; others leave their teeth unstained and wear a long, yellow mantle. The Conibo flattens his head, or that of his child, between boards into fantastic shapes, leaving holes through which the cranium can develop. He leaves single locks of hair on conspicuous promontories. Toucans’ feathers are stuck to them with wax. On days of celebration he dances in ropes of iridescent birds strung through the bills, his bead girdles of barbaric design hung with humming-birds as tassels. He knows no fashion but personal caprice. There is no limit to the vagaries of the world about him, neither are any suggested for his own decoration. Cross-wise over his shoulders he slings long scarfs of brilliantly colored birds hung at the end of chains made of their little leg-bones, along with boxes of poison for his arrow-heads. His necklaces are of the teeth of jaguars, wildcats, and monkeys, or of the curling teeth of the white-lipped peccary. From his anklets and wristlets of heavy,