d he told them that one of the best fishing-grounds
for them was off the Woolsner Shoal, some four miles further along the
beach to the eastwards, while another good place was Selsea Bill, more
eastward still.

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 abo