September 8th. The quantity of water in the river had now become so considerable as to impede our descent along the bed; but the valley was narrow, and so filled with close and entangled forests, and the uplands so broken and rugged, that no other path appeared to remain for us. We therefore continued to make our way, though with great difficulty, and found our horses much incommoded by being kept almost constantly in the water, as we were compelled to do to cross from the point of a sand-bar on one side the river, to the next on the other. Quicksands also occurred, and in places where we least expected it, our horses and ourselves were thrown to the earth without a moment's notice. These sudden falls, occasioned by sinking in the sand, and the subsequent exertion necessary to extricate themselves, proved extremely harassing to our jaded horses, and we had reason to fear that these faithful servants would fail us almost at the end of our journey. {27} Above the falls, the width of the river, that is of the space included between its two banks, varies from three hundred yards to two miles; below it is uniformly narrower, scarce exceeding four hundred yards. The beaches are sloping, and often covered with young cotton-wood or willow trees. In the Missouri, Mississippi, and to some extent in the Arkansa and its tributaries, the islands, sand-bars, and even the banks, are constantly shifting place. In the progress of these changes, the young willows and cotton-wood trees which spring up wherever a naked beach is exposed, may be supposed to have some agency, by confining the soil with their roots, and arresting the dirt and rubbish in times of high water. On the Missouri, the first growth which springs up in these places, is so commonly the willow, that the expressions "willow-bar" and "willow-island" have passed into the language of the boatmen, and communicate the definite idea of a bar, or an island recently risen from the water. These willows become intermixed with the cotton-wood, and these trees are often almost the exclusive occupants of extensive portions of the low grounds. The foliage of the most common species of willow (S. angustata) is of a light green colour, and, when seen under certain angles, of a silvery gray, contrasting beautifully with the intense and vivid green of cotton-wood.[84] Within a few yards of the spot where we halted to dine, we were so fortunate as to find a small log canoe made fast on shore. From its appearance we were assured it had been some months deserted by its rightful owner; and from the necessity of our situation, thought ourselves justified in seizing and converting it to our use. Our pack-horses had become much weakened, and reduced by long fatigue; and in crossing the river, as we had often to do, we felt that our collections, the only valuable part of our baggage, were constantly exposed to the risk of being wetted. We accordingly made prize of the