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 the bird wears his wings. The back fins of the flying fish are much longer than those of the ordinary fish, with long ribs like a bat's wings.

These long, stout fins help the fish to jump out of the water— much as you may have seen a seal jump and climb up on a rock by means of his leg-fin-flippers. Then, once in the air, Mr. Flying Fish goes on flapping his fin wings and so manages to fly about three hundred yards—or the length of two city blocks.

As a frog seems to loan his webbed feet to the swimming birds, because he tried them first and found them "handy" for paddles or oars, so fish seem to have been the inventor of wings. Later, other animals adopted the wing idea, flying frogs, flying bats, flying birds, flying squirrels. The flying frog is found in one of these warm places of the earth—the East Indies. He has much larger feet than our frogs have, and he uses the webs between his toes to help hold himself in the air as he leaps from tree to tree; for he's a tree-frog.

When men first tried to learn to fly—isn't it curious?—they did just as the flying frog and flying squirrel do. They got up on some high place, spread out something against the air to hold them up, and then jumped off. Just as little boys do when they jump from shed roofs, and try to sail down with umbrellas—only little boys mustn't do this because it's bad for the umbrella—and worse for the little boys—because it's so easy to get hurt. In the same way an aeronaut jumps from a balloon, with an umbrella-like parachute to break the fall.

If you have ever noticed a flying squirrel leap from tree to tree you have seen how useful those long thin strips of skin between his legs are to him. He can jump much farther than the ordinary squirrel because these extra strips of skin make a kind of wings to hold him up, just as the tree-frog's little umbrella feet help to support him and just as the bird's wings, not only act as sails to send him through the air, but help to support him as he flies.

Notice the flying squirrel. See, he jumps—not straight across but downward, in a slanting direction. And just before he lights he does just what a bird does before lighting—he turns and goes up again Do you know what he does this for? If he didn't do it he would strike on his nose, against the tree—and real hard, too, because he is going pretty fast. Then he'd get a nose-bleed! As it is, by turning upward in his flight, he checks himself, as a boy does when, in skating, he turns up his foot and sticks the heel of his skate into