Its last two great tributaries are the Tapajos, six times the length of the Thames, and the Xingu, twice that of the Rhine; while further east a narrow channel unites it with the River Para, into which flows the broad stream of the Tocantins. This river, rising in the Minas-Geraes, six hundred miles from Rio Janeiro, is one thousand six hundred miles long, and ten miles wide at its mouth. Opposite to Para is the large island of Marajo; and if Professor Agassiz is right in supposing that the continent once extended much further to the east than it now does, this island may properly be considered in the centre of the mouth of the river, and the River Para might then properly be called one of its true embouchures. But only a few of the streams which feed the Amazon have been named. Numberless other rivers swell its waters, united to it by countless channels which form a wonderful network throughout the whole region, joining also many of the main rivers together, with the intricate navigation of which the natives alone are acquainted. These curious water-paths, or igarapes, as they are called, are often so narrow that the branches of the lofty trees meet overhead, enabling the traveller in his canoe to proceed for miles together sheltered from the noonday sun. Here and there a glimpse of the sky can be discovered through the umbrageous foliage overhead, while birds of gay plumage flit to and fro, or sit perched on the branches uttering their strange and varied cries. In the intervals, or sometimes forming the termination of the water-path, numerous pools of various sizes exist--some a few yards across, others expanding into lakes--filled mostly by the overflowing of the main river during the rainy season. They are the habitations of a great variety of fishes. Here several species of turtles and alligators swarm in vast numbers; electric eels, too, abound in them, as well as many of the other curious water-creatures of that region. Water-fowl and various other aquatic birds dwell on their banks, while on the surface of their placid waters float the wide-spreading leaves and magnificent blossoms of the Victoria Regia, as also of other lilies and water-plants. SCENES ON THE AMAZON.