He rested upon his oars for a minute or two, and perhaps from the reflection of the masses of ferns which fringed the arch of the cavern, and which were repeated in the clear waters, Victor Pradelle's face seemed to turn of a sickly green while one hand grasped the edge of the boat with spasmodic force. "Now then, hold tight," said the rower, as a swell came from seaward, running right in and raising the boat so that by skilful management she was borne forward, right beneath the arch and then away into the depths of the cavern, leaving her rocking upon the watery floor, while it sped on away into the darkness where it broke with a booming noise which echoed, and whispered, and died away in sobs and sighs, and strange hisses and gasps, as if the creatures which made the cavern their lair had been disturbed, and were settling down again to sleep. "There, Vic," cried Harry, "what do you think of this?" Pradelle was holding tightly by the side of the boat, and gazing uneasily round. "Think? Yes: very wild and wonderful," he said huskily. "Wonderful? I should think it is. Goes in ever so far, only it isn't wide enough for the boat." Leslie looked back at the mouth, fringed with the fronds of ferns, and at the lovely picture it frame a of sunny amethystine sea; then at the rocky sides, dripping with moisture, and here of a rich metallic green, there covered with glistening weeds of various shades of olive-green and brown. "Ahoy--oy!" shouted Harry with all his might, and at the same moment he let his oars splash in the water. Pradelle leaped to his feet as there came a strange echo and a whirring rush, and a dozen pigeons swept past their heads from out of the depths of the water cave, and away into the brilliant sunshine. "Oh, if I had a gun," cried Pradelle, to hide his confusion. "What for--to make a miss?" sneered Harry. "Now then, out with those cans. Fill every one, and I'll try and knock off a few anemones for the governor." As he spoke he laid in his oars, picked a hammer and chisel from out of the locker in the forepart of the boat, and then worked it along by the side of the great cave, as from out of the clefts and crannies above and beneath the water he searched for the semi-gelatinous sea-anemones that clustered among barnacles, and the snail-like whorl molluscs whose home was on the weedy rocks. The girls aided all they could, pointing out and receiving in the tins a many-rayed creature, which closed up till it resembled a gout of blood; now, still adhering to the rock which Harry chipped off, a beautiful _Actinia_ of olive-green with gem-like spots around the mouth and amid its fringe of turquoise blue. Duncan Leslie eagerly lent his help; and, not to be behindhand, Pradelle took up the boat-hook and held on, but with the smoothness and care of a sleek tom-cat, he carefully avoided wetting his hands.