Page:Popular Science Monthly Volume 26.djvu/702

684 trunks, and multitudes of epiphytes flourish in their airy crowns, among which we are surprised to see the Clusias, themselves trees, enthroned high upon the topmost limbs. From the height of more than a hundred feet these parasites, called in the country "Scotch attorneys," and "cursed fig-trees," send their rope-like, tufted air-roots clear to the ground, to draw up water and food to their lofty abode, while they establish their mechanical security on the stem of the mother-tree by a close network of holding-roots. Sometimes the Bursera dies in the embrace of the strangler, and its trunk molders away without crumbling up, within its tight envelope, and finally falls, if it is not held up by the vines, bringing its destroyer down with it.

At Laudat, where we are to spend the night, two thousand feet above the sea, we find a better opportunity than we have ever before enjoyed to become acquainted with the structure and habits of the epiphytic phanerogams. At all other places on the island these plants live in the tree-tops, and we have to content ourselves with looking at them through the glass, or to rely for more careful examination upon such specimens as we can bring down with the gun. Here, where the forest has been cleared away for several acres, these plants have come down with the trees, and, finding enough light near the ground, live upon the bushes. They have been quite fully described by A. W. F. Schimper, in the "Botanisches Centralblatt," and we check our own observations by his account. Most of the epiphytes of Landat belong to the families of the orchids, aroids, bromelias, and ferns, while many other families are represented by individual forms.

The peculiar conditions under which these plants live require peculiar adaptations. One of their most general characteristics, and frequently a very prominent one, is the succulent or leathery constituency of their leaves, which, operating to impede transpiration, well adapts them to the dry conditions of their dwelling-place. Some of them are protected by a clothing of hairs. Many epiphytes are characterized by superficial extensions of their organs at relatively small heights above their substratum; quite usual are the arrangement in rosettes of the leaves at the base of the stem, thickenings of the stem into knots, and a creeping or climbing habit—all peculiarities denoting adaptation to the absorption of water and food, and to the gaining of a secure footing on the substratum. In the way of special adaptations, we may, with Schimper, distinguish among the epiphytes four groups, according to the manner in which they take up their food.

Those of one group simply derive their nourishment from the bark to which they are attached, and are in this respect analogous to the ground-plants. Those of the second group send down roots to the ground, besides those by which they adhere to the tree, and thus put themselves as to nourishment in almost precisely the condition of ground-plants. Of these are the Clusia, which we have described, and two plants which were conspicuous at Laudat, by their handsome