While the Captain was giving this little lecture about the crabs and their congeners, Rover was prancing around and barking for some one to pitch in a stick or something for him to fetch out of the sea. Presently, in bringing back a piece of wood which Bob had thrown into the water, Rover dragged ashore a mass of seaweed, a portion of which was shaped somewhat like a lettuce and coloured a greenish purple. The Captain pounced on this at once. "Hullo!" he exclaimed--"why, it is laver." "Isn't that good to eat?" asked Mrs Gilmour. "I fancy I've heard people speak of it in London, or somewhere." "I should rather think it was!" he replied. "It is, too, one of the best sorts, the purple laver, a variety of some value, I believe, in the London market." "I can't say I should like to eat it," said Nellie, squeezing up her nose like a rabbit and making a wry face. "It looks too nasty!" "Wouldn't you?" retorted the Captain. "I can tell you, missy, it is very good when well boiled, with the addition of a little lemon-juice. It tastes then better than spinach." "Do all these sorts of seaweed grow in the sea, Captain Dresser?" asked Bob. "I mean in the same way as plants do in a garden?" "No, my boy," replied the other. "They attach themselves to the rocks at the bottom of the sea, not to draw their sustenance from them in the same way as plants ashore derive their nourishment from the earth through their roots; but, simply to anchor themselves in a secure haven out of reach of the waves, getting all their nutriment from the water, which is the atmosphere of the sea in the same way as air is that of the land. Of course, some of these weeds of the ocean drift from their moorings, like that bladder wrack there with the berries." "Don't they pop jolly!" observed Master Bob, popping away as he delivered himself of this opinion. "Pop! There goes one!" "You are not the only boy who has found that out, or girl either," said the Captain with a smile to Nellie, who was industriously following her brother's example. "But, look here, children, I can now see something stranger than anything we've noticed yet." "What?" exclaimed Bob and Nellie together, stooping down to where the Captain was poking about with the end of his malacca cane in the sandy shingle. "What is it, sir?" "A pholas," he answered. "It is one of the most curious burrowing animals known, and has been a puzzle to naturalists for years, until Gosse discovered its secret, as to how it succeeded with its soft and tender shell in penetrating into the hardest rocks, within whose substance it is frequently found completely buried, so that, like the `Fly in Amber,' one wonders how it ever got there!" "What did you say it was?" asked Mrs Gilmour. "A `fowl,' sure? Faith it's a quare-looken' bird, Cap'en dear!" The Captain smiled, but he was not to be tempted away from his hobby.