All this passed before his eyes, as it might have done in the first days of the world. From the submarine depths, the central fire throws up a dome or cone, which opens, and its lava forms a circular crater. But the volcanic strength becomes exhausted, and the cooling lava becomes covered with a living jelly, an animal multitude, whose perpetual exudation of mucus continually raises the circle higher and higher, to low water mark; no higher, or they would be dry; no lower, because they would lack the light. If they have no special organ with which to perceive the light, it circumfuses, penetrates, permeates their whole being. The glowing sun of the tropics, which traverses right through their transparent little frames, seems to have for them all the irresistible attraction of magnetism. When the tide ebbs and leaves them uncovered, they, nevertheless, remain open, and drink in the vivid light. Dumont d'Urville, who so often coasted among their little isles, says:--"It is a real pain to see, so near by the peace of that interior basin, and to see all around shallow waters, beneath which are the shelving rocks, tenanted by the coral insects, in perfect security, while we are enduring all the shocks of a raging tempest." But this amiable community and its edifice are a shoal, a terrible lee shore, scarcely hidden by the shallow waters; touch upon that shoal and you will be crushed. Trust not to anchors among those peaked and jagged rocks; your cables, however good, would soon wear and snap. The seaman's anxiety is extreme, in those long nights when the Southern surges drive him among these shoals, at once so rugged and yet as cutting as razors.