SUMMARY.
1. The part of the body with which we think is the brain.
2. The brain is found filling the hollow place in the skull.
3. There are two brains, the large brain and the small brain.
4. Each brain is divided into two equal and complete halves, thus making two pairs of brains.
5. The brain is largely made up of very small objects called nerve or brain cells.
6. The nerve cells send out very fine branches which form the nerves.
7. The nerve branches or fibres run to every part of the body. They pass out from the brain to the rest of the body through a number of openings in the skull.
8. Most of the nerve branches pass out through a large opening at the back of the skull, in one large bundle called the spinal cord.
9. The spinal cord runs down through a canal in the backbone, and all along gives off branches to the various parts of the body.
10. It gives us pain to prick or hurt the flesh in any way, because when we do so we injure some of the little nerve branches of the brain cells.
11. When we suffer, we really feel a pain in the brain. We know this because if a nerve is cut in two, we may hurt the part to which it goes without giving any pain.
12. We have different kinds of nerves of feeling.
13. There are other nerves besides those of feeling. These are nerves of work.
14. The nerves of work have charge of the heart, the lungs, the muscles, the liver, the stomach, and every part of the body which can work or act.
15. The brain and nerves control the body and make all the different parts work together in harmony, just as a general controls an army.
16. The brain uses the nerves very much as a man uses the telephone or telegraph wires.
17. With the large brain we remember, think, and reason.
18. The little brain does the simple kind of thinking, by means of which the heart, lungs, and other vital organs are kept at work even when we are asleep.
19. The spinal cord does a still more simple kind of work. It enables us to walk and to do other familiar acts without using the large brain to think every moment just what we are doing.