Page:Evolution of Life (Henry Cadwalader Chapman, 1873).djvu/33

Rh or foot, to the rock on which it lives. It has the power of slowly changing its position by a gliding movement, but does not often do this. The free end, with the mouth in the centre, is surrounded by a wreath of arms (tentacles), which contain multitudes of minute vesicles, with coiled threads, which are often projected, and serve to paralyze or entangle living prey. These tentacles are hollow and pierced with small holes. Each tentacle leads into, or is the prolongation of, the general cavity of the body upwards; so when the Anemone shuts itself up, the water which filled it is ejected through the tentacles, making as many little fountains as the Anemone has arms. The stomach, consisting simply of two fold (Figs. 15, a, a), open below, and suspended from the mouth, is held in position by folds, called mesenteries, running to the walls of the body. (Fig. 16.) Hanging to these folds are seen the eggs, which, dropping into the general cavity of the body, come out of the mouth. The general cavity of the body is at once the common system by which the food is digested, and carried to different parts of the body, and the effete matters got rid of There are no intestines, no arteries, veins, gills, or lungs; no separation into organs; little of that division of labor which is so striking in the economy of the higher animals. The curious stones called " brain stones" are constructed by animals allied to the Anemone in structure, as are also the beautiful rocks of madrepore. The coral reefs as large as islands, indeed, often the rocks on which the island verdure has grown, are the results of the unseen, untiring work through countless ages of these minute and beautiful beings. There is nothing which gives one a more profound appreciation of the lapse of ages, of immense periods of time, than the formation of the parts of the earth constructed by such agencies.

Suppose the chambers of an Anemone to contract into canals, that this modified Anemone loosens itself, turns