Then, above the surface of the waves it nosed its way, grayish white, whalebacked. From a hundred miles distant floated a cigar-shaped mangrove-bud, bobbing vertically, through the ocean, until it chanced to touch the new-risen coral reef. The mangrove, alone of all trees, will sprout and grow in salt water. The mangrove's trunk, alone of all trunks, is impervious to the corrosive action of the sea.
At once the bud set to work. It drove an anchor-root into the reef, then other roots and still others. It shot up to the height of a foot or two, and thence sent thick red-brown roots straight downward into the coral again.
And so on, until it had formed a tangled root-fence for many yards alongshore. After which, its work being done, the mangrove proceeded to grow upward into a big and glossy-leaved shade-tree, making buds for further fences.
Meanwhile, every particle of floating seaweed, every dead fish or animal, all vegetation, etc., which chanced to wash into that fence-tangle, stayed there. It is easier for matter, as well as for man, to get entangled in mangrove roots than to get out again.
The sun and the rain did their work on this decaying stuff. Thus, soil was formed, atop the coral and in the hollows scooped out of its surface by wind or tide.
Presently, a coconut, hurled from its stem in the Bahamas or in Cuba, by a hurricane, set its palmleaf sail-sprout and was gale-driven across the intervening seas, floating ashore on the new-risen land. There it sprouted. Birds, winds, waves, brought germs of other trees. The subtropical island was complete.
Island, key, reef—reef, key, island—with the intervening gaps of azure-emerald water, bridged, bit by bit, by the coral,—to-day a sea-surface, to-morrow a gray-white reef, next day a mangrove hedge, and the next an expanse of spectacular verdure and glistening gray-white sand.
So Florida was born.
So, at least, its southern portion was born, and is still in daily process of birth. And, according to Agassiz and many another, the entire Peninsula may have arisen in this fashion, from the green-blue sea.
Dredge and shovel are laboring hard to guide or check the endless undersea coral growth before bay and channel and lagoon shall all be dry land. The wormlike, lazy, fast-multiplying Anthozoa is fighting passively but with terrific power, to set at naught all man's might and wit.