Another practice of the Aguarunas is making the _tundoy_, or _tunduli_, their jungle signal-service. They hollow a tree-trunk and make three holes in it with red-hot stones, then hang it aloft on a high tree, fastening the lower end securely to the ground. Blows upon it with a wooden mallet reverberate as far as ten miles, and form a code, by their swiftness or slowness and their pitch above, between, or below the holes. As a hundred words suffice for a language, so would three tones for a drum of war. Primitive man in the primeval jungle sending blood-curdling signals to reduce the heads of his enemies! Reverberations whose wave-lengths are intercepted on their echoing passage through the forest by the flight of royal butterflies and challenged by the chatter of antediluvian apes! The weaker tribes are actually, not in name merely, pushed back into the woods. Many traits in us find a literal, physical parallel in them. We speak of “licking the dust;” in the jungle there are tribes of earth-eating savages. A civilized man in the jungle learns their literal ways. He puts gunpowder on the bite of a serpent and cauterizes by igniting it. Having no language adequately to express the venomous thoughts they may feel, they use poisoned arrows. They literally reduce an enemy’s head, and are more humane than we, doing it after death! The Inje-inje represent the Stone Age, both in their tools and language. They come out of inaccessible hiding-places to perform their primeval rites by full moon and are the least known of all the savage tribes. This small tribe of the Inje-inje, whose name is the sum of their language, need only a word to steer their craft through life. As has been said, the development of language from the primitive Inje-inje to the somewhat developed Aguaruna can be studied in this mysterious place. No tribe can count further than ten; most of them use only a movement of the fingers. Though there are hundreds of “languages,” not one Amazonian tribe can write. * * * * * In temperate zones nature is to be relied upon. Roots grow in the ground, branches and leaves in the air, flowers come forth at certain seasons, and fruit follows. Trees give us shade in which no fever lurks. Vegetables do not relieve agony and want, as insects and plants do not cause it. No animals lie in wait to seize us, no snakes to uncurl and engulf us. Rain comes in measurable quantities. We live on a tempered, miniature scale. We can afford to neglect reckoning with nature, for we understand her laws, and we direct her by that understanding.