“No, no,” his friend answered. “Pteranodon was so big. From tip to tip of the planes or wings was nearly twenty feet. And his body was very small. Even the bones were tiny. A Pteranodon bone over two feet long and two inches in diameter, was like a piece of heavy cardboard rolled into a tube.” “Hollow?” “Quite, quite hollow. And he had very little weight to carry. We know he could not have flapped his wings very much.” “How can you find that out?” queried Perry. “No one was there to see him.” “No, no. But it takes muscle strength to flap wings, and it needs a strong breastbone to attach the muscles. The flying lizards did not have this. Then, too, the bones were too thin to flap such big wings. It was nearly all gliding. So you can see why the birds were the winners in the fight.” “I surely do,” the boy answered. “But if the bird plan won out, and the pterodactyl didn’t, why has the bat plan worked?” “The bat’s wings are four times as strong as the pterodactyl’s, because all four fingers are there,” was the reply. “Then, too, the bat is a mammal and warm-blooded. Besides which, most bats are small. The big bats fly slowly, flapping their wings like a crow.” “Were there any birds to set up in competition with the flying lizards?” asked the boy. “Not at first,” the other said. “But when the pterodactyl failed, Nature had to start on something else. So she tried birds. Still, the first ones were more than half reptiles. They even had teeth.” “Birds with teeth?” “Great long teeth,” said his friend. “I suppose, Perry, in all the history of fossil discoveries in the rocks, one of the greatest events was the day when the first bird was discovered in a rock in Bavaria which was being quarried for lithograph stone. That rock is made from a fine kind of mud, which was laid down in the Jurassic Period. One of the very first birds in the world had evidently got stuck in that mud, hundreds of thousands of years ago, and although he had struggled to get away, he was stuck fast. He had drowned and died there. “Then, day by day, week by week, the mud settled around him, until finally it reached his body and his head, and entombed him absolutely. The mud must have been coming down quite fast, for all his body was covered even before the feathers had rotted. For years and years, for centuries and centuries, mud had been deposited on top of him, thousands and tens of thousands of years had put other rock strata above the mud and then, in a later age, there had been a rising of the earth and it was all dry land once more. “Still more hundreds of thousands of years passed, and then Man came. A workman, digging out stone, saw this dead bird, even the marks of his feathers on the stone. Even then, no one could believe it was really a bird, and the jaw, which was lying a few feet away from the marks of the feathers, was thought to be the jaw of a fish.