and stronger, from pushing themselves along in the mud, and their lungs got a little more used to breathing air, instead of water, and by the time thousands of years had gone by, and the water in the marshes was nearly all dried up, the great-great-great-grandchildren of the first fish had got so used to breathing air that they did not mind it a bit, and their fins had got so used to rubbing along on the mud that they weren't fins any longer, but had changed to short, strong little webbed feet.
Mother Nature came and looked at them, and laughed.
"You see, Ocean," she said, "I knew what I was about. Your fish have turned into reptiles. They can live on land as well as in the water, and they have legs and feet."
"How did you do it?" the Ocean asked.
"I did not do it. There is a wonderful law, made by God, which takes care of all such things. No matter what sort of a life any creature is in the habit of living, if you make him live another kind of life, he will change himself to suit it. Your fish couldn't breathe air, when they first tried it, but as soon as they had to breathe it, this law I speak of helped them, so that their lungs began to change, and before long, they had grown a new pair of lungs, fitted to breathe air. It was the same way with their feet; the tender fins they used to swim about in the water with weren't hard and tough enough to scrape against the mud and rocks, so they have grown tougher and stronger fins, like little legs, to get about with. You may be sure that God knew what He was about when He planned the Universe, and made its laws. You just watch these reptiles we have made, and see what happens to them. I'll be back in a million years or so, and see how things are getting along. We'll be ready for Man pretty soon." Then Mother Nature went away to look after some comets that had gotten lost and were dashing madly through space, trying to find out where they belonged.
The Ocean watched the reptiles in the great salt marsh, and saw many wonderful things. As the water in the marsh got lower and lower, being dried up by the Sun, the mud in the marsh got harder and firmer, and the reptiles in it, who lived partly on land and partly in the water, found after a while that there wasn't enough water left for them all to live in, so thousands of them crept inland, away from the sea, and made their homes in the great fern forests, or among the rocks on the bare hillsides and plains. And no matter what sort of a life they lived, they changed to suit it.
Some made their homes in the soft earth along the edges of the marsh, squirming along on their stomachs, and as they did not need feet and legs to squirm with, their feet and legs got smaller and smaller, until they did not have any at all, and they became snakes. Some dug holes in the hard ground with their feet, to make homes for themselves, and from digging and digging, their feet became very strong, with hard, sharp nails on them. And those that lived under the ground all the time, feeding on the roots of plants, lost their eyes and became blind, because they no longer needed eyes to see with, in their dark burrows, just like the moles we see digging under our lawns to-day. Some, like the frogs and the turtles, stayed in the marshes. The frogs made holes in the mud to live in, but the turtles grew hard shells on their backs, so that they could carry their homes about with them, and sleep on the open ground without any fear that other animals could harm them. Some of the reptiles, who liked the water best, crawled out of the marshes into the rivers, and became crocodiles, and alligators, while those that went inland forgot all about the water, and instead of scales, or shiny skins, like the reptiles, they grew hair on their bodies, to protect them and keep them warm. Some, who took to living in the trees, grew sharp claws, and long legs, to climb with, while others, who did not care for climbing, but ran around on their four feet all day, found that after a time their feet grew very hard and strong, and because they did not use their toes any more, they gradually lost them, and grew hoofs, like the horse, or the deer. And some, who liked the trees better than the ground, because there were always plenty of berries and fruits to be found there, stayed in the tree-tops all the time, and never came to the ground. Their front fins had gradually become larger, from flopping them in the air all the time, and at last, after many thousands of years, these fins became wings, and the trees in the forest were full of birds.
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.
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.
The Sun looked down at the creature Mother Nature had pointed out to him, and saw a queer little animal, covered with hair, and looking somethink like a very small monkey. This animal liked the fruits and nuts of the trees, and spent most of his time in the tree-tops, but sometimes he would go down to the ground, and run about through the thick jungle forests on all four feet, like a squirrel. But when he wanted food, or when some of the fierce flesh-eating animals attacked him, he would quickly climb up into a tall tree.
The trees in those early forests grew very close together, and the little monkey animals found that they could swing from limb to limb with their arms, and thus travel for miles, from one tree to another, without going down to the ground at all. When they first took to living in the trees they had smooth skins like their parents the reptiles, but as thousands of years passed, hair grew out all over them, to protect them and keep them warm during the chilly rains.
For a long time the Sun watched these creatures, while Mother Nature was away, and he saw them slowly change. For one thing they grew larger and stronger all the time, and came to look more and more like the monkeys and apes we find in the jungle country even to-day. But still they were not apes, but from them, both the apes and Man, are descended.
From their habit of swinging from limb to limb, or from strong vines, like a trapeze performer in a circus, these ape-like animals got more and more in the habit of standing upright, balancing themselves on their hind feet on one limb, while they held on with their fore feet to another limb higher up. But still whenever they went down to the ground they ran about on all fours.
If