Part 7

Just below the place where we remember words, and a little forward of it, lies the place where we remember other sounds which are not words, such as the noises of bells and whistles, barking of dogs, mewing of cats, all buzzings and creakings and gratings and crashings, all laughing and crying. Every kind of sound which isn’t either words or music is recognized and remembered here. Beyond this spot, still farther forward and down, and just above the rear end of the cheek-bone, is the place where we remember music. If we don’t know anything about music, and can’t tell Yankee Doodle from Old Hundred, then we don’t use this part of our brains at all. But if we do know one tune from another, and know a good many to recognize them when we hear them, here is where we do the knowing.

Back of the word-seeing part of the thinking spot, and reaching pretty well round to the back of the head, lies the place where we remember everything we see, except words written or in print. Above the word-speaking part of the brain, or speech center, from which we control the mouth, throat, lips, and tongue, which we use in speaking, lie the various points from which we manage other parts of the body. As you might expect, next the speech center lies the center for the rest of the face and for the head and eyes. Above that comes the center for the hand and arm. Still higher up, right on the top of the head, comes the center for the legs. So whenever we do anything with any part of the body, we have to signal the proper muscles from the part of the brain that lies between the tip of the ear and the top of the head. Close behind this region is the spot where we feel everything that touches the skin; so that we can make the movement and feel the results most handily.

So as you see, the surface of the brain is a sort of map or chart of the entire body. Every muscle, every point on the skin, the eyes, the ears, the nose, the tongue, every several organ which we possess, has its own special spot on the surface of the brain, somewhere above or behind the ear. Each half of the body is charted on one side of the brain, a spot in one for each spot in the other. But we who have to use these brains to think and remember with, as well as to see and hear and feel with, and to control our muscles, have chosen to do this thinking and remembering with the spot on the left side of the head which corresponds to the muscles of the lips and mouth and tongue, and to the eyes and ears and the right hand. Thus we have everything convenient, all in one small spot on one side of our heads, where we can get at everything with the least trouble. But what the front part of the brain is for, is something that nobody knows much about.

Certain very strange results follow from this practice of ours of using only one side of the brain to think, remember, and speak with; and using different parts of that for thinking and remembering about different sorts of things. Once upon a time there was a workman who was hit hard enough to break his skull, on the left side of his head, pretty well round toward the back, and just over the spot where, as I have explained, are stored up all the memories of things seen. He seemed not seriously hurt; but when his wife came to see him at the hospital, he did not know her. Neither did he know his children nor his friends. In fact, he didn’t even know that they were human beings. He had absolutely lost the memory of everything that he had ever seen.

But the minute his wife spoke he knew her at once. Or if he could feel of any familiar thing he knew what it was. All the while, he could see perfectly well. His eyesight remained as good as ever, he simply couldn’t remember that he had ever seen things before. The plain seeing, he could do with either side of his head; and the left side being hurt, he did it with the other. But the remembering that he had seen the same thing before, he did with the left side only; and when he could no more do it with that, he could not do it at all. Yet his memory for sounds and the feeling of things was just as good as ever; because the places where he did these sorts of remembering were not under the place where he got hit. And the moment the doctors lifted out the splinter of bone that was pressing on his seeing-things spot, then he remembered wife, children, friends, everything as before.

Here is another case, much like the first, and yet curiously different: An educated woman, somewhat well along in years, went to bed at night in ordinary health. During the night, however, a small blood vessel burst and formed a tiny blood blister on the left side of her brain, about an inch in front of the spot where, as I have been telling, the workman was hit who couldn’t remember his wife when he saw her. She had, in short, a sort of internal black eye, just on the spot that she had been using for sixty years and more to remember written and printed words.

She woke up in the morning, therefore, totally unable to read a single word. She could see as well as ever, understand perfectly every word said to her, speak and write without the least difficulty—but she simply could not read. Give her a printed book, she could count the letters in every word, draw them on paper, tell which were tall, short, round, or square, see them in fact just as well as before—but she no longer knew what they meant. It was exactly as if she had never learned to read at all; and being much too old to learn again, she never read another word as long as she lived.

There is another accident which is so little uncommon that probably every one who reads this book will some time in his life see an example of it. This is a case where a blood vessel bursts on the left side of the brain and wrecks the speech center. The person to whom this happens, immediately forgets how to talk. If the blood clot is small, so it presses upon the speech center and nothing else, the victim of this sort of accident can read and write as before, and understand all that is said to him. Oddly enough, too, he can make any sound that he ever could, and repeat parrot-like any words that he hears. But he cannot remember the meaning of words. He is precisely like a man suddenly transported to a foreign country where they speak a language which he never heard. His own language has become to him like Chinese.

Strange indeed are the freaks of these accidents to the left side of the head above the left ear. One man, a musician, finds that while he can hear music as before, he hears it only as noise, and no longer recognizes it as tunes. He has been hit low down on the side over the spot where he keeps his music memory. Another, hurt a little higher up, can hear noises as before, but cannot tell a factory whistle from a church bell. Not that they sound alike; but he has forgotten which is which. Occasionally, a watch-maker, engraver, or other skilled artisan, will get an injury well up on the side of his head at the place from which he manages his right hand. Then he loses all his special skill of hand. He can still use his right hand for ordinary acts, dressing, eating, shoveling coal; but the power of doing thinking-things is gone. He has become like a day laborer who has never learned a skilled trade.

There is a strange case of a business man who got a blood clot just over his word-thinking spot, but toward the upper side so that while it ruined his speech center and the place where he kept his memory for the look of printed words, his memory for the sound of words escaped. He could neither read nor write, nor speak a word; but he could understand what was said to him. Curiously enough, he could handle figures as well as ever, for the figure-remembering spot and the figure-writing spot had escaped. So for seven years this man kept on with his business. Every letter had to be read to him; and all he could do in answer was to write down figures and point to them. Meanwhile, he took lessons most diligently, trying to learn to write and speak with the other side of his brain. But it was no use.

There was also a learned man, who in addition to his native language, which was English, knew Greek, Latin, and French, and could besides read music. After his accident, he could read his native English only with the greatest difficulty, about like a child of six or eight who can make out easy words, slowly; while writing, he could scarcely read at all. French, he could read much better; as well, say, as a high school graduate. Latin he could handle pretty well; about like a boy just out of college. But Greek and music he could read and write exactly as well as he ever could. The accident, which had pretty well spoiled the place where he remembered his native language, had only damaged the spot where he remembered his French, had hardly touched the place where he remembered his Latin, and had missed entirely the place where he kept his memory of music and Greek.

You understand, of course, that when one of these very same accidents occurs to a left-handed person, no matter how much it damages his head on the left side, it does not destroy his speech or memory. Or if the same thing happens to a right-handed person, on the right side of the head, his speech and memory do not suffer. The hurt has to be on the thinking side in order to affect the thinking.

When little children are hurt in these ways, at first they suffer loss of speech or memory just as men and women do. But little children, as I have already explained, are not hard and set like grown up people. They can start over again, and learn to think, speak, and remember with the other halves of their brains. But as soon as any one gets too old and stiff to learn anything new, then he is too old to learn an old thing over again on the other side.

Do you see now why you have to go to school five hours a day, and sit on a hard seat studying still harder lessons, when you would much rather sneak off and go in swimming? It is so that you may build up these thinking spots in your brains. We are born with brains like the animals, alike on both sides. Only slowly, painfully, with much hard and disagreeable work, that we had a great deal rather not do, do we manufacture a one-sided human brain. We begin young, while the brain is still growing. With years and years of work and study, we slowly form the thinking spots over our left ears, which we are to use the rest of our days. When we are grown up, we can no more form new thinking places on one side of our heads, than we can form new thinking places on the other side, after the old ones have been destroyed. The business man who lost his ability to read, never learned to read again, tho he worked at it six years, harder than any child ever studied. If he had put off learning to read till his old age, he could never have learned at all.

It does seem a long time that we sit on a piano stool doing our daily practicing, and mighty little fun. Let us then remember that all the while, we are making a time, tune, and harmony remembering place just back of the left temple, and tying it up with the spot farther up on the side of head from which we manage our hands and fingers. It is slow work; but when once we get the job done, we shall be able to enjoy and remember music with it for the rest of our lives—forty, fifty, sixty years. Surely, this is cheap enough at the price of a little daily practicing.

It really is a good deal as if we were born like a dog or a horse, with head, body, and legs, but no hands, and had to make our hands for ourselves. How we should work in such a case, building our fingers, shaping our thumbs, and in every way getting the best possible sort of hands to use thereafter. And what should we think of any careless child who left off a finger or two, or was too lazy to put on a proper thumb, and so had to be deformed and crippled all the rest of his life.

But the thing which makes us different from dogs and horses, isn’t half so much our hands, as it is the spot of brain substance which we build for ourselves over our left ears. This spot looks like the corresponding spot on the other side. But somehow or other, nobody knows just how, our work and study and trying hard make that particular patch more important for us than anything else in our whole bodies. If we fail to build good thinking spots while we are young, we shall be deformed and crippled for the rest of our lives.

XXI

Where Some Of The Animals Do Their Thinking

It really is a great advantage to us to bring all our thinking into one small spot, where everything is handy to everything else. It is, in fact, almost like the convenient little kitchens they have on railway dining cars, where the cook can reach every dish and pan and kettle, cupboard, stove, refrigerator, coal-bin, pantry, china closet, and all, without shifting his feet or hardly even turning round. If you want to understand how great this advantage is, consider the case of some animals who not only have no words to think with, but in addition, do their remembering and thinking, such little as they do, at several different places or all over their bodies.

There, for example, is the sea-anemone, such as one finds at the sea side, in the salt water pools, after the tide has gone out. Beautiful creatures they are, set solidly on thick muscular bodies, and pushing out their long pink or yellow tentacles, a dozen or twenty of them, sometimes, like the petals of a daisy. Only you must be careful not to alarm this animal flower. If you do, sometimes if you so much as let your shadow fall across him, in an instant he will pull in those pretty tentacle-petals, and turn to a lump of tough jelly, almost as hard, and not much more interesting, than half a rubber ball; and there you will have to sit and wait and wait for something to happen, only it never does, until somebody makes you come in and change your shoes.

However, if you are careful, you can begin to feed this animal flower with bits of meat or fish. Drop a morsel cautiously on one of the tentacles, and he will reach out with the tentacles near by and roll the food slowly over and over, until finally, with much difficulty, he will get it into the center of the disk where his mouth is. Then he will slowly open his mouth and work it in. In short, the tentacles are the sea-anemone’s hands and fingers; but he feeds himself clumsily enough, and cannot make any movement quickly or certainly, except shutting up when he is frightened.

If you think you can fool the little animal by feeding him with pieces of shell, or wood, or pebbles, or anything that is not food, you will soon find out that he is wiser than he looks. These things, which he cannot eat, he simply lets fall off his tentacles to the ground. But real food he will eat and eat and eat, till he swells up and up and up, and you think he is going to burst, only he never does; and in time, if you do not get tired feeding him first, he will take the food more and more slowly, and finally will refuse it altogether.

Now if instead of feeding the sea-anemone with pieces of meat, you press the meat against blotting paper so that the paper soaks up the juice, and then feed the creature, sometimes with real meat, sometimes with blotting paper and meat taste, at first he will swallow both with equal avidity, not knowing apparently the difference. After a half dozen trials, however, he will begin to take in the blotting paper somewhat less rapidly than the meat. He will continue to take the paper with more and more hesitation until after some twenty trials or so, while he swallows the meat as before, he will refuse to take the paper at all. He has learned the difference.

All this time, you must have taken pains to offer the real food or the imitation to the same tentacle, so that the same fingers shall have stuffed the morsel into the mouth. If now, after the polyp has thoroly learned the difference between meat and paper, on one side of his mouth, you try feeding him in the same way on the other side, you will discover that the new side knows nothing whatever about what has been happening on the other. The anemone which has learned to take meat and leave paper on one half of his body, still takes them both on the other half, and it will take just as long to teach the difference to the second side as it has already taken to teach it to the first.

The reason for this peculiar behavior is simple. The sea-anemone, instead of doing the remembering for his whole body, all in one spot, as we do, spreads it out over a ring of brain which circles the mouth, between the mouth and the base of the tentacles. He does the remembering for each tentacle close to the base of the tentacle itself. Each therefore remembers something of what has happened to itself, something less of what has happened to its next neighbor, still less of those beyond, and almost nothing at all of what has happened to the tentacles clear over on the other side, a whole inch away.

Even that much remembering, however, the tentacle-brain does not do especially well. After the animal has learned his paper-meat lesson thoroly one day, and can tell the difference straight off every time, the next day he has as thoroly forgotten it. If he learns it once more on the second day, he will as completely have unlearned it again on the third, and will swallow paper and meat with equal zest.

So much then for animals who do their thinking in rings instead of in spots. Now we shall see what happens to a creature who tries to do his thinking all over his body.

I have already mentioned the infusoria which swarm by the thousands in the water of ditches and puddles. They are decidedly small animals, the largest of them no bigger than a pin head; and as I explained before, they are remarkable in that each infusorian is just one single cell. Most of them are free-swimming, that is, they go about as they like thru the water as a fish does; but some grow on stalks like flowers, tho even these can usually let go their anchorage and float away to a new station.

Small as they are, they feed on still smaller plants, the bacteria. Nevertheless, they do not know their food either by sight, hearing, taste, or smell. One hungry infusorian, looking about in search of his dinner, will pass right by a mass of bacteria large enough to feed him the rest of his life and not notice it. He will swim so close as almost to graze the feeding ground, yet keep straight along without turning or pausing, as if it were not there. The next instant, he may run against some small particle which isn’t good to eat at all, and swallow it down forthwith. In fact, the infusorian simply swallows whatever happens to hit his mouth. If this happens to be good to eat, why so much the better. If it happens to be only a grain of dust or a fleck of shell, down it goes just the same; the infusorian doesn’t know the difference.

When the infusorian, swimming straight ahead, runs into some obstacle too large to swallow, it stops, backs off, turns a little to one side, and goes ahead again. But he never takes any pains to turn toward the side which will do the most good, or to notice whether he turns enough to do any good at all. He is just as likely, having run against the extreme end of some object, to turn exactly the wrong way, so that he hits it next time fairly in the middle. Then he backs off once more, turns again, and swims ahead. Perhaps this takes him by; perhaps he butts the obstruction again at the spot where he struck it first. Then he tries again, and yet again, and in the course of time, usually manages to get by.

So the infusorian is a funny little machine, made so that when it hits anything it backs off, turns somewhat, and goes ahead again. If one is very clever with his fingers, as men who study creatures such as these have to be, one can take a slender needle and touch the infusorian on the front end—we cannot call it the head. Thereupon he stops, backs, turns, and goes ahead. Touch him on his side. Again he stops backs, turns, and goes ahead. Prick him from behind. Once more, he stops, backs—right on to the needle which is pricking him—turns, and goes ahead. Try heating the water. As soon as the infusorian feels uncomfortably warm, he stops, backs, turns, goes ahead. Try cooling it. The same process. Add to the water something that the creature notices, acid for example. Still the same old stop, back, turn, go ahead; tho often the next go-ahead sends him straight into the drop of acid and burns him up.

So far as we can see, therefore, everything that the infusorian feels at all, feels to him exactly like everything else. No matter what it is he feels, nor on what part of his body he feels it, he always acts in precisely the same way. It is, moreover, doubtful whether one of these animals ever learns or remembers much of anything, or in any other way ever finds out how to do anything which he could not do about as well the first instant of his life.

XXII

What Plants Know

Of course, the plants do not really _know_ anything. Still they usually act wisely; and that is practically just as good as knowing, and often looks very much like it.

For instance, one sees little pine trees growing in a pasture. Each year they send up a “leading shoot” a foot or more long, straight up into the air, to become by and by the main trunk. Each year, also from the point where the trunk ended the year before, there starts out a whorl of little branches, a half dozen or so of them, some of which will by and by become the main limbs. It is the same way with the firs and spruces. If you haven’t seen these growing out of doors, you have at least had them for Christmas trees in the house.

When these little trees grow in the pasture, pretty soon a cow comes along and eats off the top so that there is no longer any leading shoot to grow up into a trunk. What does the tree do then, but pick out one of the side branches from the uppermost whorl, and turn that up into a new leading shoot. So the tree gets a trunk in spite of the cow. Somehow or other, nobody understands how, one of those green tufts which was meant to grow into a horizontal branch, changes its mind, turns up, and becomes the vertical trunk.

This may happen five or six times to a single tree—for when it isn’t cows, then it’s wind, or insects, or something else, that kills the bud that ought to grow up into the main trunk. So one finds often in the woods, trunks of evergreen trees that grow up straight for a few feet; then take a sharp turn to one side, and another straight run of trunk; then another turn. Each of these turns means that something has happened to the leading shoot, and that the tree, like a very wise vegetable, has at once made another leading shoot out of a side branch. But still the curve remains to show where the branch had to change its mind.