Although the pororóca breaks as far up the Araguarý as midway between the Veados and the entrance to the Apureminho, its violence seems to be checked by the narrowing of the stream below the Veados, by the turns in the river, and by the vegetation along the banks.
This vegetation is of a kind against which it seems to be least effective—namely, bamboos. They grow next the stream from near the mouth to the foot of the falls above the colony, and for much of the distance form a fringe to the heavy, majestic forest behind them, than which nothing could be more strikingly-beautiful. The clusters next the stream droop over till their graceful plumes touch the surface of the water, and, as the plants grow older, they droop lower, until the stream is filled with a yielding mesh of canes. I measured a number of these bamboos, and the longer ones, taken at random, were from twenty to twenty-five metres in length and from seven to ten centimetres in diameter. A more effectual protection against the pororóca could hardly be devised.
On Bailique and Brigue I found the forests very different from any I had hitherto seen in the tropics. These islands, like all the others in this part of the country, are flooded at high tide during part of the year, and, as a consequence, they are very like great banks of mud covered with the rankest kind of vegetation. This vegetation varies with the locality. All around the borders the island of Brigue is fringed with tall assai palms, bamboos, and various kinds of tall trees, all of which are hung with a dense drapery of sipós (lianes) and vines, which form an almost impenetrable covering. Inside of these are several palms, the most common being the ubussú (Manicaria saccifera). The next in order are the murumurú (Astrocaryum murumuru), urucurý (Attelea excelsa, the nut of which is used for smoking rubber), and ubim (Geonoma). But, unlike most tropical forests, this one has very little or no undergrowth, except upon the borders. Most of the ground was under from one to six inches of water, while the exposed places were covered with fine sediment deposited by the standing muddy waters of the Amazon. I walked several miles through this forest without finding any palms except the ones mentioned. The little ground above water was covered with the tracks of deer, pacas, cutias, and of many kinds of birds, mostly waders; but the death-like stillness was unbroken, save for the little crabs that climbed vacantly about the fallen palm leaves or fished idly in the mud for a living.
This half-land and half-water condition of the country is common not only in the immediate vicinity of the mouth of the river, but through a very large part of the valley of the Amazon, and is one of the most impressive features of this wonderful region.
