In other words, according to these Roman traditions here poetized, the heat dried up the rivers of Europe, Asia, and Africa; in short, of all the known world. Ovid continues: "All the ground bursts asunder, and through the chinks the light penetrates into Tartarus, and startles the infernal king with his spouse." We have seen that during the Drift age the great clefts in the earth, the fiords of the north of Europe and America, occurred, and we shall see hereafter that, according to a Central American legend, the red rocks boiled up through the earth at this time. "The _ocean, too, is contracted_," says Ovid, "and that which lately was sea is a surface of parched sand, and the mountains which the deep sea has covered, start up and increase the number of the scattered Cyclades" (a cluster of islands in the Ægean Sea, surrounding Delos as though with a circle, whence their name); "the fishes sink to the bottom, and the crooked dolphins do not care to raise themselves on the surface into the air as usual. The bodies of sea-calves float lifeless on their backs on {p. 160} the top of the water. The story, too, is that even Nereus himself and Doris and their daughters _lay hid in the heated caverns_." All this could scarcely have been imagined, and yet it agrees precisely with what we can not but believe to have been the facts. Here we have an explanation of how that vast body of vapor which afterward constituted great snow-banks and ice-sheets and river-torrents rose into the air. Science tells us that to make a world-wrapping ice-sheet two miles thick, all the waters of the ocean must have been evaporated;[1] to make one a mile thick would take one half the waters of the globe; and here we find this Roman poet, who is repeating the legends of his race, and who knew nothing about a Drift age or an Ice age, telling us that the water _boiled_ in the streams; that the bottom of the Mediterranean lay exposed, a bed of dry sand; that the fish floated dead on the surface, or fled away to the great depths of the ocean; and that even the sea-gods "hid in the heated caverns." Ovid continues: "Three times had Neptune ventured with stern countenance to thrust his arms out of the water; three times he was unable to endure the scorching heat of the air." This is no doubt a reminiscence of those human beings who sought safety in the water, retreating downward into the deep as the heat reduced its level, occasionally lifting up their heads to breathe the torrid and tainted air. "However, the genial Earth, _as she was surrounded by the sea_, amid the waters of the main" (the ocean); "the springs dried up on every side which had hidden themselves in the bowels of their cavernous parent, burnt up, lifted up her all-productive face as far as her neck, and [1. "Science and Genesis," p. 125.] {p. 161}