for the earthworm to turn and twist and move forward and to shrink.
Yet, in making those ring muscles for the earthworm, Mother Nature's shuttle shot back across the web. She dropped the bones she made for the sponge and star-fish. One thing at a time, she says. I'll go back for those bones, when I get ready to put the earthworm into a shell. The crawfish is only a worm in a shell. The spider, the ant, the bee and the fly are all ring-jointed, but have no shell. When she got up to insects, Mother Nature dropped the bone or shell idea, to make better brains and senses. The bee, the ant, and the spider have such large brains, in proportion to their bodies, that they are a wonder to men.
Having made brains and sensitive nerves, Mother Nature began to use bones again. But when she made ring bones along the back of the fish, she dropped behind in brain power. A fish isn't nearly as bright as an insect. A reptile is a little brighter than a fish, a bird—you know how "smart" a crow is? By and by, Mother Nature made little boys and girls who can read, and understand this story of life.
It is very important to have a backbone, something to stand up with. You saw that in the great world of plants, when the simple yeast cell was slowly changed into the noble forest trees. All animals with a backbone are put into one class, called vertebrates. Those without backbones are called invertebrates.
Man is the most wonderful of all the animals, but even he isn't as clever in everything as are many of his humble relatives. He cannot swim like the fish, nor fly like the bird. That is he cannot do these things at first. But he has brains to "think out" things. Then he can build ships and flying machines.
When he first comes into the world, man is the most helpless of all animals, and he remains helpless the longest. But that is an improvement. It was a great thing in the history of life when animals began to think about their babies, and about taking care of them. Little insects born as creeping larva, are able to take care of themselves as soon as they come out of the cocoon. But they never get very far, and they soon die. It is only when animals begin to spend a part of their lives learning things of their mamas—as spiders and ants and bees and birds do—that they amount to much.
The children of savage men—such as Indians—live longer with their parents and depend upon them more than do the animals, and so they learn still more. White children spend still more of their
