As we follow up the rivers from the shore, we see the mangroves breaking their dense wall, while reeds and bambus fill the gaps; until at last mangroves have disappeared, as the rich valleys are reached. And now no one, or two, or six species can claim supremacy. Two trees are, however, prominent, where man has not interfered,—the cohune and the mahogany; both trees of attractive form and size, and both by their presence indicating the richest soil. The unspoiled forest of the river region presents a wonderful variety above the ground; but among its roots the exceptionally rich soil is almost bare, dwarf palms, wild bananas, gingers, and ferns scantily covering its surface. From the trees hang long vines (_vejucos_), some of them of value for cordage, others, as the paullinia (_P. sorbilis_) and zarza (_Smilax sp._), possessed of medicinal properties, while others are full of grateful sap. Endless variety reigns, and on every side the puzzled observer sees different trees. Often the stems are so covered with orchids, aroids, and other parasitic and climbing plants that they can hardly be recognized, and their leaves and flowers are but a part of the fresh canopy some sixty feet or more above the ground. From a mountain ridge this forest looks like a level plain, even as the top of a well-trimmed hedge; its surface is here and there broken by the giant mahogany, or seamed by the river and its affluents. Rosewood, cedar, palo de mulatto, cacao, figs,[48] are all here, and the palms, from the noble cohune to the insignificant chamaedoras, are plentifully scattered among the other trees. During the season of flowers the brilliant yellow of the wild tamarind (_Schizolobium_), the equally bright magenta of the Palo de Cortez, and the white of the plumosa, appear to the observer from above like a rich mosaic, while all this color is invisible to one who is beneath these trees. All vegetation here is not merely luxuriant, it is composite. There are no solitary trees, no hermits, in the vegetable world. Every trunk is but a trellis for vines, some of them, like the matapalo, strangling the fostering tree, or a nest for plants that do not seem able to get up in the forest on their own stems. If I find a branch in blossom, I must make sure that it is of the tree itself, and not part of some mistletoe-like hanger-on. I have seen single trees bearing on their trunk and branches enough orchids and other choice plants to stock a hothouse. The matapalo deserves more than a passing word, for it is the type of a numerous group of plants in the tropics. This vine may start from the ground, but quite as often it germinates in the hollow of a branch, or among the other parasites of the higher branches; in either case it is at first a slender, innocent-looking vine, clinging timidly to the tree for support and protection. Soon the vine grows until its proportions resemble those of a huge serpent, and it has reached the