Day after day we steadily pursued our course up the river, which, for the most part, retained the same dreary, monotonous aspect of low, bush- clad, mangrove-lined banks, and practically the same width, save where, at occasional intervals, it widened out and became dotted with islands, some of considerable size.  At length we arrived at a point where the land on the western bank rose into a range of hills some eight or nine hundred feet high, densely clothed with vegetation to their summits. This range of hills extended northward for a distance of about thirty miles before it once more sank into the plain; but before it sank completely out of sight astern more high land was sighted ahead, and two days later we found ourselves navigating among some very picturesque scenery, with high land on both sides of us, some of the peaks being twelve to fourteen hundred feet high.  Late in the evening of the second day after entering upon this picturesque stretch of the river we arrived at a point where the stream forked into two of apparently equal width and depth, one branch striking away to the eastward, while the other continued its northerly course.  Here my savage companions proceeded with the utmost caution, frequently landing and sending one or two of the party away to reconnoitre, and otherwise behaving as though they feared attack; but after a slow and anxious progress of some twenty hours' duration they seemed to consider the danger as past, and once more pressed boldly forward.