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.
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?
CHAPTER XX.
THE VARIETY OF MACHINERY IN ANIMALS.
You have seen what a variety of curious machinery there is in our bodies for our minds to work, besides that which is needed to keep the body in repair. But I have told you some things about other animals as I have gone along. There is in them also a great deal of machinery, and it is different in each. The variety of it is wonderful. You see that the world is every where full of many kinds of animals, making it a very busy world. I do not believe that you have ever thought how different they are from each other. I will therefore tell you a little about this.
Machinery in the oyster suited to its wants.
See what a difference there is between man and some animals. Look at the oyster. He lives in the water, shut up in his rough shell. He is no traveler. He has no eyes to see sights with. He has no sense of smell. He has taste for his food, and, no doubt, enjoys it. He has the sense of touch; this he needs, both to manage his food and to guard himself against harm. As he does not move about, and has no feet or hands, he has but few muscles. He has one to shut up his shell tight, which he does when he is alarmed. His brain and nerves are very small affairs, for he has little use for such things.