CHAPTER XIX.

THE BRAIN AND NERVES IN ANIMALS.

[Sidenote: The brain the mind’s central workshop.]

I have told you how your mind learns about the world around you, and how it makes use of its knowledge by means of the machinery of your body--the muscles, bones, etc. Your mind is in the brain, and uses the brain to think with; and from the brain branch out all the nerves by which it works all the various machinery of the body. Your brain, then, may be considered the central workshop of your mind; or it is like an engine-room of a factory, where the engine is that keeps the machinery in other parts of the building in motion.

[Sidenote: How animals learn.]

The different animals have a brain and nerves just as you have, and their minds in their brains learn about things around them. They do not learn so much as your mind does, it is true; but they really do learn. If you look at a kitten when it is first born, it is very much like a baby. It does not know any thing. But, like the baby, it knows more and more every day, and when it gets to be a cat it knows a great deal; and all that it knows has come to its mind in the same way as what you know has come into your mind. It has come in through its senses. All its knowledge came in at its eyes and ears, etc., and got to its brain by the nerves.

[Sidenote: The mind of a kitten as it plays.]

The mind in animals, too, uses the muscles in the same way that your mind does. Watch a kitten at play. The muscles that move her paws are directed by her mind in the brain by means of the nerves. As she pokes at the thing that you hold out to her, the nerves of her eyes are telling the mind in the brain all the time about the string, and then the mind is telling the muscles of the paws what to do. See her as she springs to catch the string that you draw along on the floor. As she watches it, messages are going from those bright eyes to her mind in the brain; and then, as she springs, messages are sent from her brain to a great many muscles in different parts of her body. The mind tells the muscles just when and how to act, and they all do exactly as the mind tells them. The mind of a cat sets a great deal of machinery at work when she makes a spring to catch any thing.

[Sidenote: The minds and brains of insects.]

What I have told you about some animals is true of all. The little insect that flies out of the way when you strike at him has a little brain, and there his mind thinks about what it sees, and hears, and feels, etc., just as your mind does; and when he flies away so quickly from the blow that his eyes see coming, his mind tells the muscles to make the wings go. There are nerves that carry messages from his senses to the mind in his brain, and there are nerves that carry messages from his brain to his muscles, as there are in you. The brain is very small, and the nerves are very fine, but they do their work well. They make a little telegraph, but it is a good one.

What a quantity of thinking there is done in the brains of all the animals in the world! How busy their minds are, receiving reports from their senses, and working all the machinery of their bodies. Go out into the garden, and see the birds, the butterflies, the bees, the flies, the ants, the frogs, the toads, and the worms; they are all busy thinking. They can not move without thinking. It is their thinking that makes their muscles move them. And they think about what they move for.

[Sidenote: Animals that think more than others have larger brains.]

Some of them think more than others. The bird thinks more than the worm. Some think faster than others. The humming-bird, that darts so quickly from flower to flower, thinks as fast as he works. But the lazy toad is a slow thinker. His mind does not work the machinery of his muscles much, and so does but little thinking. But even he once in a while thinks quickly. Let a fly walk along pretty near him, and he will catch it with his tongue so quickly that you can not see just how he does it. He watches the fly intently, keeping very still all the while; and when it gets near enough, he thrusts out his tongue, and the fly is gone. You would hardly think that so lazy-looking an animal could do any thing so quickly. But he is nimble as a fly-catcher, if he is not nimble at any thing else; and very quickly must the mind in his brain think when it is working its fly-catching machinery.

The more an animal thinks, the larger is the brain as compared with the rest of the body. Man thinks more than any other animal, and so he has a large brain. But the oyster has hardly any thing that can be called a brain, for in his still life, shut up as he is in his shell, he thinks but little. But such animals as horses, dogs, cats, birds, monkeys, etc., have quite large brains, for they think a great deal. Their brains, however, are not, by any means, as large as the brain of man is in proportion to the size of the body.

[Sidenote: The brain compared to machinery.]

This is as we should suppose it would be. The brain is the machinery with which the mind thinks. Now, whenever we see a great deal of machinery together at work, we know that it is because there is much to be done by it; and when we see a small machine that has not many different parts, we know that it is not intended to do much. So it is with the mind’s thinking machinery. The brain of an animal that thinks but little is small and simple; but the brain of one that thinks much is large and has many parts. Though animals do their thinking with their brains as we do with ours, there is some thinking that we do that they can not. There are some things about which they know nothing. But I will tell you about this in another chapter.

_Questions._--What does your mind do with your brain? How is your brain like the engine-room of a factory? What is said about the minds of different animals? How is a kitten, when it is first born, like a baby? How does it learn? What is said about the mind, and brain, and nerves of an insect? What is said about the quantity of thinking done in the brains of animals? How do some differ from others in their thinking? Tell about the toad. What is said about the size of the brain in different animals? How is the brain compared with machinery?