height of forty feet, and clouds of vapor rise in a constant stream. With the exception of the Salto Bello of the Rio Sacre and Utiarity Falls of the Papagaio, we had seen nothing to compare with São Vicente during our entire journey across Brazil. That night we reached the first settlement, a small village named Doze de Novembro. We arrived tired and wet, for it had rained the greater part of the afternoon, but we congratulated ourselves upon having performed a remarkable day’s work. The place was overrun with ants, not the comparatively harmless _carregador_ ants, which are content to carry away your clothing piecemeal while you sleep, but with endless armies of the fierce black carnivorous species that prey upon every living being. These ants are one of the scourges of the tropics; whether in the fever-stricken Chocó on the west coast of Colombia, at the base of Duida on the Orinoco, or in the wilds of Matto Grosso, the ravaging hordes seemed always the same. One moment they hurry along in solid formations, the next side-lines have been thrown out in all directions, covering many square yards of ground. Not one leaf or crevice escapes the alert scouting-parties, which ascend even to the top of the tallest tree. When a victim is discovered the news in some mysterious way is flashed to the main column, and battalions of reinforcements immediately rush to the encounter, charging the prey and clinging with vise-like mandibles to any part of its body that offers a hold. Usually the approach of the devastating host is preceded by a swarm of panic-stricken insects, crawling, hopping, and flying in their endeavors to escape destruction; large, hairy tarantulas crawl to the tops of bushes and leap from leaf to leaf, only to be discovered and routed, until in despair they spring to the ground, which by this time is one surging mass of ants, where they are despatched in short order. I have seen scorpions and centipedes eight inches long suffer a similar fate; no living thing seems to escape the avalanche of destruction. Flocks of ant-birds usually follow in the wake of the army, feeding upon the ants and upon the insects that have been driven from their hiding-places. One of the questions that naturally arises in this connection is how the callow young of birds escape from the ants, as caged birds are not immune from their attacks, and dead or wounded birds placed near the army’s line of march are quickly discovered, torn to shreds, and carried away. While in British Guiana I had been watching the nest of an ant-wren containing two helpless young, placed in the crotch of a tree a few feet above the ground, for several days; one morning the whole region was swarming with ants and the nest was empty; however, not long after, and also on subsequent days, both parent birds were seen contentedly carrying food into a thicket fifty yards away. A casual search failed to reveal the new nest, but to my