"There are believed to be a great many of them," answered Arthur, "and it is supposed that new ones are constantly being formed by the labours of the coral insect. A bare ledge of coral first appears, just at the surface; it arrests floating substances, weeds, trees, etcetera; soon the sea-birds begin to resort there; by the decay of vegetable and animal matter a thin soil gradually covers the foundation of coral; a cocoa-nut is drifted upon it by the winds, or the currents of the sea; it takes root, springs up, its fruit ripens and falls, and in a few years the whole new-formed island is covered with waving groves." "Mr Frazer says he has no doubt that these seas swarm with such islands, and that many of them have never been discovered," said Max; besides, here's poetry for it:-- "`O many are the beauteous isles, Unseen by human eye, That sleeping 'mid the Ocean smiles, In happy silence lie. The ship may pass them in the night, Nor the sailors know what lovely sight Is sleeping on the main;' "But this poetical testimony will make Arthur doubt the fact altogether." "Not exactly," answered Arthur, "though I am free to admit that without Mr Frazer's opinion to back it your poetical testimony would not go very far with me." "Hark! There go Mr Frazer's two barrels," cried Max, as two reports in quick succession were heard, coming apparently from the grove, in the direction of the spring; "he has probably come across a couple of `rare specimens,' to be added to his stuffed collection." CHAPTER THREE. THE ALARM AND THE CONFLICT. THE MUTINEERS--THE RACE FOR LIFE--THE CORAL LEDGE--A FINAL EFFORT--A BRIEF WARNING--THE STRANGE SAIL. "Now bend the straining rowers to their oars; Fast the light shallops leave the lessening shores, No rival crews in emulous sport contend, But life and death upon the event depend." The next moment we were startled by a quick, fierce shout, followed immediately by a long, piercing, and distressful cry, proceeding from the same quarter from which the reports of fire-arms had been heard; and before we had time to conjecture the cause or meaning of these frightful sounds, Morton bounded like a deer from the grove, about a hundred yards from the spot where we were standing, and ran swiftly towards us, crying out--"To the boats! for your lives to the boats!"