"Yet," said the other, smiling, "the birds
don't have it all their own way. Sometimes the fish gobble them!"
"Can they eat birds?"
"It's a little rare," was the reply, "but there's one authentic case on record in which a fish's stomach was found to contain no less than seven wild ducks."
"Why, I always thought that fish had a small mouth in proportion to their size. It must have been a monstrous big one!"
"It was not much more than four feet long," was the reply; "but it is one of the few fishes having a huge mouth. They sometimes call it a goosefish, because it attacks wild geese, but the right name is fishing-frog or angler. It glides along the bottom until directly beneath where ducks are feeding, and when one dives for worms in the mud—you know the way ducks go down—the angler catches it by the neck and drags it down and then swallows it at leisure. You see the bird hasn't a chance, because all the angler-fish has to do is to hold it until it strangles."
This led to a discussion of the food of fishes, and under the spur of the boy's questions, the scientist outlined for him the dietary of almost
every fish that swims, together with all the various ways in which water is aerated, such as the growth of water-plants and the currents of streams.
"It still seems to me," said Colin, "that nearly every fish lives by fighting some other fish. It's a wonder," he added, with a laugh, "that there aren't some professional fighters among them."
"There are," his friend replied; "that is to say, in the sense you mean. There's a fish which is called the fighting-fish, that is regularly trained by the fishermen, and the combats are so famous that when one is scheduled to come off a big crowd gathers."