“Good-morning, Professor.”

“Good-morning,” replied the Crab as they swam past. Just then a curious-looking little creature covered all over with little prickly spikes called out rudely,—“Yah! old Professor Crab—who caned the Oyster?” and scuttled away behind some seaweed.

“That,” said the Crab, “is one of the Sea Urchins; they are very rude and ill behaved. I do not allow my scholars to associate with them.”

“Are you really a Professor?” asked Boy, who felt greatly impressed with the Crab’s importance.

“I’m afraid I am,” said the Crab. “All schoolmasters are, you know—whether they admit it or not.”

“What do you mean?” exclaimed Boy. “I don’t think my schoolmaster is a Professor; at any rate he does not call himself one.”

“Ah, that’s his artfulness,” said the Crab. “A professor,” he explained, “is one who professes to know more than he really does, and all schoolmasters do that more or less, whether they admit it or not—they are obliged to; however, let’s change the subject; it is a painful one.”

Boy was greatly surprised at this admission on the part of the Crab, but he was too much interested in his strange surroundings to think much about it.

They were walking along a roadway with great seaweeds planted at regular intervals on either side, and in the distance Boy could see the outlines of some great buildings.

“Why, there are some houses!” he exclaimed in surprise.