Coral is built by living creatures, near the surface of the water. All that the waves have to do is, firstly, to bring abundance of food to the polyps, when alive, since by reason of their ponderous rock-skeletons they cannot go in search of food; and secondly, after the death of the polyps, to break and grind and heap together the skeleton-remains. We have seen something of ocean “stone-makers,” in the story of Chalk. Here we have the same thing again. As the tiny shells, which go to the building of chalk, are the dead remains of once-living jelly-specks, so these great masses of coral, forming islands and reefs in southern seas, are largely the skeletons of once-living polyps. A coral-polyp, like a jelly-speck, has power to take lime from sea-water. It has power to secrete carbonate-of-lime. It has power to deposit that carbonate-of-lime in solid masses. But whereas the jelly-speck lives inside its shell, putting out tiny temporary limbs through holes for food, the coral-polyp more often lives outside its skeleton, clothing the dry bones with translucent jelly. This is rather more after the fashion in which man clothes his skeleton. Yet because of its make the coral-polyp cannot properly, in the full sense of the word, “secrete” or hide its internal framework. It is hardly fair to speak of “the polyp” and of “it” in this connection. “Polyps” and “they” are more correct. For the coral-polyps live in close communities, in very near fellowship, acting on co-operative principles of the most advanced kind. Each individual may, it is true, have its own mouth, its own tentacles, and even its own small stomach. But the latter at least can hardly be reckoned as personal property, since all are so connected that liquids pass freely from one to another, and the food which is taken in by one polyp helps to nourish its neighbours. And again, while we speak of coral as being “built,” that really is not the right word; unless we may also talk of the “building” of a man’s skeleton, or of an elephant’s framework. “Built” undeniably it is; but the building implies no conscious effort, no deliberate intention, no praiseworthy exertions, on the part of the builder. Coral is simply “secreted”--is unknowingly and without choice put together by the polyps. There _is_ invention; there _is_ plan; there _is_ design. But these belong to a Mind, above and beyond and out of sight; not in anywise to the live jelly which clothes the coral-skeleton, or to the extremely limited understanding of that co-operative jelly-sheet. Not all polyps have stony skeletons. On our sea-shores we have species many, and individuals by tens of thousands, which secrete no coral. They are known to us as Sea-Anemones: and the first-cousins of these dainty flower-like beings, inhabiting British salt-pools, construct miles and miles of coral far off in southern seas.