sn't that interesting?" asked the Merboy when he had finished. "Very," returned Jimmieboy. "But I don't see how it proves that the Porpoise knew any more than the Professor. Did he know why men have chins and why boys are noisy?" "I don't suppose he did," returned the Merboy; "but even if he didn't his ignorance wasn't any greater than that of the Professor, while the Professor had to admit that there wasn't anything he could tell the Porpoise that the Porpoise hadn't heard before. That proved that the Porpoise knew quite as much as the Professor did; and the fact that the Porpoise knew how to get the Professor home while the Professor didn't, showed that the Porpoise knew more than he did. That simply proves what I have already said, that sea creatures know more than land creatures--even Porpoises, and they know less than any other kind of fish." "It looks true," said Jimmieboy. "But I hardly believe it, though." "Well, you'd better," retorted the Merboy. "Why, people of your kind say themselves that fish is good for their brains. Why should this be so if fish weren't what I've said they are?" "That's so!" Jimmieboy answered, convinced at last. "But it seems queer." "That's because you don't understand it," said the Merboy, patronizingly. "If you were a fish you'd understand it, but being a boy you can't be expected to. It's simple enough. You people on land are kept so busy all day long earning your living that you don't have time really to study. On the other hand, we sea people don't do anything but swim about all day and think. Didn't you ever notice me up there in the aquarium lying perfectly motionless in the water with my eyes gazing off on both sides of me with a far-away look in them?" "Often," said Jimmieboy. "And I've wondered every time what you really were doing. Were you always thinking at those times?" "Always," said the Merboy. "Always studying out something." "And did you ever find out anything?" queried Jimmieboy. "Yes," said the Merboy. "I've found out everything; but," he added, hastily, "don't ask me to tell you everything now because these Dolphins are a little skittish, and I've got to keep my mind on them or we'll be upset." Here one of the Dolphins, to show how skittish he could be when he tried, stood erect on his tail, and then took a header deep down into the water, and in a moment Jimmieboy found himself clinging in alarm to the Merboy's arm. "Don't do that!" cried the Merboy, "or you'll surely upset us." "I was afraid he'd drag us under," panted Jimmieboy, releasing his hold. "Drag us under?" repeated the Merboy. "Why, my dear boy, we are under. We've been driving under water for ten minutes now. In ten more we shall be on the ocean's bottom."