"One of 'em's dried up. Here's the other."

He handed Ned a queer-looking fish, almost black, about eight inches long, very slender, and very singularly shaped.

"See," he said; "its jaw protrudes in so queer a way that I can't make out which side of the creature is top and which bottom. Turn either side you please up, and it looks as if you ought to turn the other up instead; and then the thing has a sort of match-lighter on top of his head, or on the bottom--I don't know which it is. Look."

He pointed to the creature's head. There was a flat, oval figure there, made by a ridge in the skin, and the flat s.p.a.ce enclosed within this oval line was crossed diagonally by other ridges, arranged with perfect regularity. The whole looked something like the figure on the opposite page.

[Ill.u.s.tration]

"Now, what I want to know," said Jack, "is what sort of fish this is, which side of him belongs on top, and what use he makes of this match-lighter."

"I'm afraid I can't help you much," said Ned. "A year ago I would have told you at once that the fish is a shark's pilot, so called because he follows ships as sharks do, and the sailors think he acts as a pilot for the sharks. But now I don't know what to call it."

"Why not?" asked Charley.

"Because I don't know. I've been reading up in the cyclopaedias and natural histories and ichthyologies about our fishes down here, and have found out that whatever I know isn't so."

"Why, how's that?"

"Well, take the whiting, for example. When I began reading up to see if there was any sort of cousinship between him and the dolphin, I soon found that the whiting isn't a whiting at all, but I couldn't find out any thing else about him. The whiting described in the books is a sort of codfish's cousin, and he lives only at the North. Neither the pictures nor the descriptions of him at all resemble our whiting, so I don't know what sort of fish our whiting is. I only know that he isn't a whiting, and isn't the remotest relation to the dolphin, because he is a fish and has scales, while the dolphin is a cetacean."

"What's a cetacean?" asked Charley.

"A vertebrated, mammiferous marine animal."

"Well; go on; English all that."

"Well, whales, dolphins narwhals, and porpoises are the princ.i.p.al cetaceans. They are not fish, but marine animals, and they suckle their young."

"Well, that's news to me," said Charley.

"Now, then," said Jack, "if you two have finished your little side discussion, suppose we come back to the subject in hand. What do you know, Ned, about this fish that I have in my hand, and why don't you call him a shark's pilot now, as you say you did a year ago?"

"Why, because the books treat me the same way in his case that they do in the whiting's. They describe a shark's pilot which is as different from this as a whale is from a heifer calf, and so I don't know what to call this fellow. Did he make a fight when you caught him?"

"Indeed he did. I was sure I had a twenty-pound something or other on my hook, and when I pulled up this insignificant little creature, with the match box on his head, I was disgusted. I looked at him to see if he hadn't a steam-engine somewhere about him, because he pulled so hard, and that's what made me observe his match box and his curious up-side-down-itiveness."

"I say, Ned," said Charley, "why is it that our Southern fishes are so neglected in the books?"

"Well, I've asked myself that question, and the only answer I can think of is this: in the first place, there is no great commercial interest in fishing here as there is at the North; and then the natural history books and the cyclopaedias are all written at the North or in Europe, and so there are thousands of curious fish down here which are not mentioned. There's the pin-cushion fish, for example. I can't find a trace of that curious creature in any of the books."

"What sort of thing is a pin-cushion fish?" asked Jack.

"He's simply a hollow sphere, a globular bag about twice the size of a walnut, and as round as a base ball."

"Half transparent, is he? Red, shaded off into white? with water inside of him, and pimples, like pin-heads, all over him, and eyes and mouth right on his fair rotundity, making him look like a picture of the full moon made into a human face?" asked Jack eagerly.

"Yes, that's the pin-cushion fish."

"I thought so. That's my other one," said Jack.

"What do you mean?" asked Ned.

"Why, that's the other thing I had to show you, but couldn't find. I caught him with the cast net."

"And kept him to show to me?" asked Ned.

"Yes, but he disappeared."

"Of course he did. He spat himself away."

"How's that?"

"Why, if you take a pin-cushion fish out of the water, and put him down on a board, he'll sit there looking like a judge for a little while; then he'll begin to spit, and when he spits all the water out, there's nothing left of him except a small lump of jelly. They're very curious things. I wish we had a good popular book about our Southern fishes and the curious things that live in the water here on the coast."

"Don't you suppose these things are represented at all in scientific books?" asked Jack.

"I suppose that many of them are, but many of them are not, and those that are described, are described by names that we know nothing about, and so only a naturalist could find the descriptions or recognize them when found. With all Northern fishes that are familiarly known, the case is different. If a Northern boy wants to find out more than he knows already about a codfish, he looks for the information under the familiar name 'Codfish,' and finds it there. He does not need to know in advance that the cod is a fish of the _Gadus_ family, and the _Morrhua vulgaris_ species. So, when he wants to know about the whiting that he is familiar with, he finds the information under the name whiting; but the scientific men who wrote the books, however much they may know about the fish that we call whiting, do not know, I suppose, that it is anywhere called whiting, and so they don't put the information about it under that head. They only come down South as far as New Jersey, and tell about a species of fish which is there called whiting, though it isn't the real whiting. If they had known that still another and a very different fish goes by that name down here, they would have told us about that too, in the same way."

"What's the remedy?" asked Charley.

"For you, or Jack, or me," answered Ned, "to study science, and to make a specialty of our Southern fishes. When we do that and give the world all the information we can get by really intelligent observation, all the scientific writers will welcome the addition made to the general store of knowledge. That is the way it has all been found out."

"Why can't we begin now?"

"Because we haven't learned how to observe. We don't know enough of general principles to be able to understand what we see. Let's form habits of observation, and let's study science systematically; after that we can observe intelligently, and make a real contribution to knowledge."

"You're not going to write your book on the Marine Fauna of the Southern States to-night, are you?" asked Jack.

"No, certainly not," said Ned, with a laugh at his own enthusiasm.

"Then let's go to bed; I'm sleepy," said Jack.

CHAPTER VII.

AN ENEMY IN THE CAMP.

The three tired boys went to sleep easily enough, and the snoring inside their hut gave fair promise of a late waking the next day. But before long Jack became restless in his sleep, and began to toss about a good deal. Charley seemed to catch his restlessness, and presently he sat up in the bunk and began to slap himself. This thoroughly aroused him, and as Jack and Ned were tossing about uneasily he had no scruple in speaking to them.

"I say, fellows, we're attacked."

"What's the matter?" muttered Ned, at the same time beginning to rub himself vigorously, first on one part of the body, then on another.

"Mosquitoes," said Jack, violently rubbing his scalp.