After dark our men indulged in a curious native dance which I had never seen before in South America; they collected a great heap of wood and soon after supper had a roaring bonfire going; then they formed a circle, with one man in the centre who began to sing in a high, strained voice, and after each line the whole chorus answered with a wail that sounded something like “_oh-tee-oh-tee-ah_.” The centre man bowed and hopped about on one foot in a most ridiculous manner and made frequent sudden charges into the surrounding company, and if he succeeded in knocking one of them down that man took his place in the middle of the ring. The whole performance looked very much like an imitation of a cock-fight. Some of the onlookers had rattles made of small calabashes full of pebbles stuck on a short piece of bamboo, which they shook in rhythm with the singing; they seemed perfectly insatiable of this form of amusement, and the dancing and howling lasted far into the night. Below São Feliz we found another small launch towing a _batelão_, which in the course of a day took us to a camp called Tabajara. We had not gone more than a few miles the next morning when further progress was again barred by rapids. After a short walk we crossed a branch of the river in small dugouts and then started on a two-mile portage through the flooded forest. Another launch was waiting below the rapids, but within twenty minutes after weighing anchor we again heard the roar of troubled waters ahead of us; the river raced between high, rock-strewn banks. In the distance we could see flecks of foam dotting the surface, while a cloud of mist hung over the river; but from beyond the veil that obstructed our further view came the ominous roar of a great cataract, growing in intensity as we drew near. The landing was about a hundred yards above the brink of the first fall, but the current proved to be too strong for the launch’s little engine, and we were in danger of being swept past; the moments that followed were exciting, but fortunately we managed to reach the bank. This same thing had occurred but a short time before, but the result had been disastrous; the boat was swept over the falls, and, of the thirty-one men aboard, twenty-seven were never seen again. The portage around these rapids, called São Vicente, was about a mile and a half in length and led over gently undulating country, all heavily forested. In many places the bed-rock had been uncovered by the torrential rains. This consisted of fine-grained, dark granite; usually there was a shallow layer of sand on the rock, with a thick covering of rich black mould. From the top of a high knoll we had a fairly good view of the falls and of the rapids below; after leaping over a twenty-foot ledge the river rushes through a narrow rock-filled gorge; enormous boulders tower out of the channel like so many black, unvanquished monarchs. Tongues of spray leap to a