At the very moment he did so, and touched the ground underneath, another great wave, curling resistlessly behind him, caught him up on its crest, whirled him heavenward like a cork, and then dashed him down once more, a passive burden, on some soft and yielding substance, which he conjectured at once to be a beach of finely powdered coral fragments.  As he touched this beach for an instant, the undertow of that vast dashing breaker sucked him back with its ebb again, a helpless, breathless creature; and then the succeeding wave rolled him over like a ball, upon the beach as before, in quick succession.  Four times the back-current sucked him under with its wild pull in the self-same way, and four times the return wave flung him up upon the beach again like a fragment of sea-weed.  With frantic efforts Felix tried at first to cling still to Muriel—­to save her from the irresistible force of that roaring surf—­to snatch her from the open jaws of death by sheer struggling dint of thews and muscle.  He might as well have tried to stem Niagara.  The great waves, curling irresistibly in huge curves landward, caught either of them up by turns on their arched summits, and twisted them about remorselessly, raising them now aloft on their foaming crest, beating them back now prone in their hollow trough, and flinging them fiercely at last with pitiless energy against the soft beach of coral.  If the beach had been hard, they must infallibly have been ground to powder or beaten to jelly by the colossal force of those gigantic blows.  Fortunately it was yielding, smooth, and clay-like, and received them almost as a layer of moist plaster of Paris might have done, or they would have stood no chance at all for their lives in that desperate battle with the blind and frantic forces of unrelenting nature.

No man who has not himself seen the surf break on one of these far-southern coral shores can form any idea in his own mind of the terror and horror of the situation.  The water, as it reaches the beach, rears itself aloft for a second into a huge upright wall, which, advancing slowly, curls over at last in a hollow circle, and pounds down upon the sand or reef with all the crushing force of some enormous sledge-hammer.  But after the fourth assault, Felix felt himself flung up high and dry by the wave, as one may sometimes see a bit of light reed or pith flung up some distance ahead by an advancing tide on the beach in England.  In an instant he steadied himself and staggered to his feet.  Torn and bruised as he was by the pummelling of the billows, he looked eagerly into the water in search of his companion.  The next wave flung up Muriel, as the last had flung himself.  He bent over her with a panting heart as she lay there, insensible, on the long white shore.  Alive or dead? that was now the question.

Raising her hastily in his arms, with her clothes all clinging wet and close about her, Felix carried her over the narrow strip of tidal beach, above high-water level, and laid her gently down on a soft green bank of short tropical herbage, close to the edge of the coral.  Then he bent over her once more, and listened eagerly at her heart.  It still beat with faint pulses—­beat—­beat—­beat.  Felix throbbed with joy.  She was alive! alive!  He was not quite alone, then, on that unknown island!