The kinds of food the new animals ate had a great deal to do with their shapes and sizes. Some, like the deer, the huge elephants we call mammoths, and the giraffes, who came later, grew very fond of the fresh green leaves of the trees, and ate them most of the time. The giraffe got into the habit of reaching up so far for the tender leaves that his neck grew longer and longer, until now he has the longest neck of any animal in the world. Some animals, instead of eating leaves, or fruit, learned to eat other animals, and so their teeth and claws got very large and sharp, and their bodies very quick and strong, like the lions and tigers, so that they could jump upon the creatures they ate and tear them to pieces. Because the Earth was so warm and comfortable, and there was plenty to eat, some of the animals grew to be very large. There were mammoth elephants, two or three times as large as the elephants we see in the circus to-day, with shaggy hair, and long curving tusks to fight with. And there were animals like lizards, some of them almost as big as whales, and others with long necks, and wings like a bat, that flew about over the marshes, eating smaller animals, or the leaves of plants and trees. As the Earth became cooler, many of these early sorts of animals died out, became extinct, as we call it, and we only know that they once lived, because sometimes we find the bones or skeletons of them lying in beds of clay or rock. [Illustration: BEFORE MAN Because the Earth was so warm and comfortable, and there was plenty to eat, some of the animals grew to be very large.] All these changes the Ocean watched while Mother Nature was away, and the laws that God had made to govern the Universe filled him with wonder. Even in his own kingdom of the sea he saw strange things—flying fish, and others that grew swords at the ends of their noses, to spear their enemies with. And he even saw, at the very bottom of the sea, where it is always dark, fish that grew little electric lights like the lights of a firefly, by which they were able to see their way about in the darkness. When the new animals had spread all over the edge of the Earth, Mother Nature came back to see how everything was going. "Splendid," she said, when she had looked things over. "The plants, and the fish, and the animals are all doing very nicely indeed. Now we are ready for Man." CHAPTER III THE APE THAT WALKED LIKE A MAN WHEN Mother Nature told the Sun that the Earth was at last ready for Man, the Sun did not quite understand her. "What kind of creature is this Man you are always talking about?" he asked. "Wait and see," Mother Nature replied, "and while you are waiting, just keep your eye on that funny little animal running about there in the woods—the one with the long arms and legs and tail. I'll be back after a while and tell you more about him." Then she went away.