Our Indians were all well armed and frequently took long shots at some of the creatures that ventured to show themselves in the early mornings or just before dark. They were expert archers and even shot large birds on the wing as the flocks passed overhead. Occasionally an otter appeared, always a hundred yards or more away, swimming rapidly with only the head showing above the water. These animals were favorite targets, and from my seat in the middle of the canoe I had an unobstructed view of the arrows in flight as they left the bow of the man in front; he did not aim at his prey, but quite some distance above it. At the twang of the bow the arrow sped into the air, ascending slightly at first, and then dropping as it approached the mark; it described a curve exactly like a bullet fired from a rifle, and remained in a perfectly horizontal position during the entire flight. When making camp on a sand-bank the Indians stuck their bows and arrows in the ground, near the shelters; this prevented their being stepped on and broken. In damp or rainy weather the arrows warped badly, but it was only a few minutes’ work to heat them near a fire and bend them back into alignment. Tropical rivers are noted for their treachery. One can never be certain of their actions or character, even a few hours hence. We had a striking example of this on the Chimoré. Camp had been made on an extensive sand-bank one day at noon, as we planned to spend a few hours hunting and fishing in the neighborhood. The sun shone brightly and there was nothing to indicate a change of conditions in any manner whatever; but scarcely had the canoes been unloaded and a fire built over which we intended to do the cooking when we were startled by a dull roar that grew louder with each passing second; before we had time to hurriedly gather our belongings and throw them into the canoes a foam-capped, seething wall of water was upon us, sweeping down the river and carrying away everything in its path. As the tidal wave, several feet high, dashed over the sand-bank, the imprisoned air shot up from the great cracks and rents in the sun-baked earth, and set the raging mass of muddy water to hissing and boiling. In a few minutes only the higher mounds of sand projected above the roaring inferno, and against these hungry tongues of water lapped greedily until their bases were undermined. Then the whole mass crumbled and disappeared in the seething flood. Where our peaceful camp had stood but a few minutes before there was now a sea of agitated water. The explanation of this phenomenon is simple: A heavy rain had fallen in the mountains where the tributaries of the river rise, and the torrent of water dashing down the precipitous slopes had rushed into the lowlands. After this the water was so muddy that it was unfit for use without special preparation. In order to secure a supply for drinking and cooking we boiled a quantity of it; the sand was quickly precipitated to the