But whatever the form of the tree trunks may be, the shallow soil upon the hills and the marshy soil in the lowlands, has taught them that there is greater safety and stability in a broad foundation than in a deeply penetrating one, and so almost without exception the tree roots spread out widely, on, or near, the surface. Beneath the protecting shelter of these patriarchs, as completely protected from scorching sun and rushing wind as if in a conservatory, grow innumerable varieties of palms, young trees destined some day to be giants themselves, and others which never attain great size. Still lower down, luxuriate smaller palms, tree ferns, and dense underbrush, and countless vines. These latter, however, are by no means confined to the underbrush, many of them climb to the very tops of the tallest trees, cling about their trunks and bind them to other trees and to the ground with the toughest of ropes. With one or two exceptions these vines are an unmitigated nuisance. To them more than to anything else is due the impenetrableness of the tropical thicket. Of all sizes and all as tough as hemp lines, they creep along the ground, catching the traveler's feet in a mesh from which release is possible only by cutting. They bind the underbrush together in a tough, elastic mat, which catches and holds on to every projection about the clothes, jerking revolvers from belts, and wrenching the rifle from the hand, or, hanging in trap-like loops from the trees, catch one about the neck, or constantly drag one's hat from the head. The one exception noted above is the _bejuco de agua_ or water vine. This vine, which looks like an old worn manilla rope, is to be found hanging from or twined about almost every large tree upon elevated ground, and to the hot and thirsty explorer it furnishes a most deliciously cool and clear draught. Seizing the vine in the left hand, a stroke of the _machéte_ severs it a foot or two below the hand, and another quick stroke severs it again above the hand; immediately a stream of clear, tasteless water issues from the lower end and may be caught in a dipper or _á la native_ directly in the mouth. A three-foot length of vine two inches in diameter will furnish at least a pint of water. The order of cutting mentioned above must invariably be adhered to, otherwise, if the upper cut be made first, the thirsty novice will find he has in his hand only a piece of dry cork-like rope.