Part 4

Oddly enough, most living creatures do not grow old. They simply live along till some other creature comes along and eats them up, or till the cold weather comes on and they freeze. A fresh egg is so soft that it hardly holds together; a young chicken is as tender as you please; while an old hen has to be boiled for days in order to be eaten at all. But an old fish isn’t tough; neither is an old lobster. Who ever heard a cook asking for little oysters, for the sake of getting them tender and juicy, or a fisherman preferring small fish? We like these the better, the older and larger they are. All animals, before they hatch out of the egg, are very soft. Afterwards they all grow larger and harder. But some stop growing big and continue to grow hard; and some stop growing hard and continue to grow big. The first sort grow old; the second do not.

Now when you come to think of it, about the only animals that grow old are the four-footed beasts, ourselves, and the birds. But the rate at which these various creatures grow old may be very different indeed.

Let us take a new-born human baby, and a new-born puppy, and a new-born mouse. All these are helpless little babies; and all three start immediately growing up and growing old. But while it takes six months for the human baby to grow to be twice as large as it was at birth, the puppy doubles its weight in nine days; while the little mouse, in the first twenty-four hours doubles its weight twice, so that at the end of its first day of life it is already four times as large as at the beginning.

At six months, the human baby, if he is very much up and coming, as you no doubt, my reader, were, can just begin to sit up without a pillow at its floppy back; it cannot walk a step, and it hasn’t a tooth in its head. But a six months puppy is a wiggly little beast, who runs away miles when he gets lost, chews up the family overshoes, and is well on the way toward losing his milk teeth. Meanwhile the mouse has grown up to be as large as he ever will be, has children of his own and probably grandchildren.

At five years the mouse is dying of old age. The puppy has become a sedate and middle-aged dog; but the baby is still a little child, just beginning to go to school, and still some years from losing its first tooth. At ten years, the child is young, the dog is old, and the mouse has become ancient history.

You musn’t think that the larger animals live longest. A horse is as large as six or eight men, but it is old long before a man first votes, and the birds, which are in general much smaller than the beasts, also in general live three, four, and five times as long. Even the elephant, thought to be longest lived of all beasts, lives no longer than we. But fish and turtles and crocodiles and shell-fish and the like, which are neither beasts nor birds and grow big without growing old, may outlive even parrots, elephants and men.

I dwell upon this at some length because there is no doubt that just as the dog grows old more slowly than the mouse, and the man grows old more slowly than the dog, so some men grow old, more slowly than others. Some people have used up their lives and are old at fifty or sixty; some are still young and hard at work at seventy and eighty. Now it rests partly with ourselves which we shall be. Five is not a large number to multiply by. But five times your present age, my reader, will take you well up to middle life. In no small degree, it is for you to choose whether you will come to five times your present age with the best part of your lives over and done with, or with the best part still to come. What, in general, your fathers and mothers are telling you is right and teaching you to do, will contribute to the one result; what in general they are telling you is unwise and wrong will doom you to the other. That indeed is how we know that some things are right and others things are wrong. People have tried, many times over, and found out, to their profit or to their cost.

XI

Why We Grow At All

Did you ever stop to think how extremely convenient it is to have two parents? Mama stays at home and takes care of the little children, reads and sings to them, tells them stories, puts them to bed, spanks them when they are naughty and kisses them when they are good. Indeed, you couldn’t get on very well without Mama. Neither could you get on very well without Daddy. Daddy doesn’t seem so important as Mama; but if Daddy didn’t go to work every day, and earn money for Mama and their little boys and girls, where would house and food and clothes and birthday parties and music lessons all come from?

Suppose there were no Mamas at all, but only just Daddies. Then of course there would be no aunties, nor nurses nor cooks nor big sisters nor kind ladies in the next house. There would be only just men; and half the men would have to stay home from the office to take care of the little boys of the other half, and then their work wouldn’t get done, and there would be no end of trouble.

It would be almost worse if there were only Mamas and no Daddies. For then all the Mamas would have to go out to work; and even when they could earn enough to hire a nurse, which I am afraid would not be often, the best of nurses isn’t like Mama. So it is really much better as it is, when we have both fathers and mothers, one to work abroad, and the other to work at home and take care of the children.

In fact, this arrangement is so much better than any other that pretty much all the living world has adopted it. You know the ears of corn which we buy in August and September and eat off the cob. You know too how it comes from the shop, all wrapped up in soft green husks, with the long silk hanging out of the end, that little girls in the country use for dolls’ hair, and ridiculous little boys try to smoke in pipes. The ear is the mother corn, and the kernels wrapped snugly away in the green husk are her children. Or rather they are her eggs, with the little corn plants inside, almost ready to be dried over winter and be planted and start life for themselves. Each kernel of corn has one fibre of silk, which is joined to it at one end and hanging out of the ear at the other.

The ear, then, is the mother of the corn. Its father is the tassel at the top of the stalk. From each branch of the tassel hang many tiny brown bags, each about as large as a grain of rice, and each filled with a very fine brown dust. This dust is called pollen. And unless a grain of this pollen falls on each thread of silk of each ear, then the kernel at the other end of the thread will never grow to full size and never become a seed; but will always remain small like the undersized kernels at the end of the ear. If the tassel is cut off; or the silk pulled out; or the ear tied up in a paper bag, then the ear forms no proper seed.

Sometimes, on an ear of sweet corn, one finds a few kernels, or a single kernel only, that instead of being white like the rest, is yellow. This means that somewhere in the neighborhood, it may be miles away, somebody has planted a field of common yellow corn, which we make into corn meal, but do not eat off the cob because it isn’t sweet. A grain or two of pollen from this yellow corn has been carried by the wind and fallen on the silk of an ear of sweet corn. So the father of that particular kernel is yellow and its mother white, and the kernel is colored just as if a white woman had married a Negro or an Indian.

Different plants manage these things differently. The ancient Egyptians, who lived on dates much as we live on corn and wheat, used to plant orchards of date palms as we plant orchards of our fruits. Every year, at the time when the cultivated date trees were in blossom, the Egyptian farmers used to go out into the desert, cut branches from certain wild palms which never bore fruit, and carry them in procession thru their date orchards. They did not know why they did this. They only knew that if they omitted the ceremony for a single year, that year they got no fruit. We know now, of course, that the date-bearing palm is the female tree; and the wild palm which doesn’t bear anything is the male. The procession with branches thru the orchards simply brought in the pollen.

Most plants, on the other hand, not to take any chances, have seed and pollen in the same flower. Many too, instead of relying on accident and the wind to carry one to the other, are arranged so that insects and humming-birds, in seeking food, shall make the transfer. Some, few, however, like the willows, have seed and pollen on separate trees.

The water plants manage in much the same way. They, for the most part, turn loose in the water what in them corresponds to the pollen, and waves and currents carry it to the young seeds. The simpler water animals, sponges and sea-anemones and shell-fish do much the same. While the female sea-urchin or star-fish produces eggs as small as dust, the male produces a still finer pollen-dust, which we call milt or sperm. If one grain of this happens to float against an egg, the egg at once begins to change to a young animal. Otherwise after a week or so the egg dies and that is the end of it. Of course, under these conditions, the chance of egg and milt getting together is pretty slim, and the waste of eggs is enormous. So the fishes, which can move about, have a much better plan. When the female salmon, for example, swims up the rivers to leave her eggs among the gravels in the swift water, the male goes along with her. After she has laid her eggs and gone away, along comes her mate and scatters milt over them. So the salmon egg is pretty sure to grow; and the salmon can afford to have few eggs and larger, and so give her little ones more yolk to live on and a better start in the world.

The bees have a still better device. The single queen bee, as everybody is supposed to know, lays all the eggs of the hive. When the queen is young and the new swarm is just starting, she annexes enough of this pollen-milt-sperm to last her the rest of her life, and stores it up in a little sack. Then whenever she lays an egg, all she has to do is to give this sack a squeeze, press out a little of the contents, and start the egg growing into a new bee.

Strangely enough, however, altho this practice of having two parents is so very common among both animals and plants, and so universal among human beings, it is not, so far as we can see, at all necessary. Potatoes are thick underground branches, and not seeds at all. Yet we plant them and they answer exactly as well. Many lowly creatures, like the yeasts, the bacteria, the infusorians of stagnant water, and the like, never have anything resembling seeds or eggs. There is a parent. The parent splits in halves. There are two children. And where is the parent?

Among the common green plant-lice which swarm on the leaves in the summer, the males all die early in the season. After that the females go on laying eggs, and these hatch more females which lay more eggs, for ten and twelve generations, before the cold weather comes on and some of the eggs begin to hatch out males once more. They get along exactly as well when each insect has only one parent, as when it has two.

In the case of the queen bee, if while the egg is being laid she squeezes the sack, then the egg hatches out a worker, which has therefore, two parents. But if she does not, then the egg hatches out a drone, which has only one. There are many other strange facts of this sort, which have been known for a long time, but which nobody has yet been able quite to understand.

Some facts still stranger have recently come to light. It has found that in the case of many sea creatures, star-fish, sea-urchins, shell-fish and others, that if the eggs are kept in common sea water, but kept carefully away from any milt, they soon die, and never grow up at all. But if any one of a considerable number of substances is added to the water, sugar, salt, acids, and other things, then the eggs, tho they still have only one parent, proceed to grow into the proper sort of little sea creatures, just as if they had two.

It is really a great mystery; the most that any one can say is that the eggs are there, but something in the water, or the absence of something, stops their growing. Add sugar, salt, acid, or milt and they grow. In the case of the land animals, this something is probably in the blood—for as you know, the blood is salt like the sea, and in many other ways much like it.

At any rate, this is practically a most convenient arrangement. A mother bird, for example, is herself born with all the eggs she is ever going to lay already formed inside her. But something in her blood keeps those eggs from growing bigger than pin heads. They don’t grow into proper eggs, that can hatch into little birds, until the mother bird gets a mate to help her build the nest, and to feed the little birds when they come, and sometimes to feed her too. Then some of them do grow up and hatch; and the two old birds take care of them.

But as I said, it is all a very great mystery, which the wisest men do not yet completely understand, and little boys and girls can hardly expect to understand at all.

XII

Things That Do Not Have To Be Learned

So far in this book, we have been learning about the body. We know something about the wonderful life-jelly of which all living things are made—how it is itself the soft parts of plants and animals, and how it builds for itself the hard shell and bones and wood, which are its supports and its tools. We know, also, something about how each particular animal or plant or human being starts as a minute fleck of this life-jelly, grows to be, first a seed or an egg, and then a full grown animal, a man, or a tree. We know, too, something of the living bricks which build the bodies of living creatures; and something of the difference between young creatures and old ones. More than this, I trust, we have learned that all this curious information is not to be looked at merely as something interesting or amusing; but that like all the teachings of science, it is something that will help us to live wisely. For as we come to know, we ought also to learn to do; and while we are finding out something about living things, we ought also to be finding out something about living.

We have, I say, thus far been learning about our bodies. Now we shall turn to a still more important part of us, and try to learn something about our minds. Our bodies, we found, are very much indeed like the bodies of animals and even of plants. Perhaps we shall find that our minds also are like those of other living things. Perhaps we shall find them to be something very different indeed.

Most of us, I suppose, have seen at least one little baby. I don’t mean a small baby merely, one that sits up in its carriage with a pillow behind its back, and smiles up at you when you look in under the hood. I mean a real little baby, a week or two old, that can’t turn its head over on the pillow or put its hands anywhere in particular, and instead of being nice and pink, is as red as a little beet—for the little baby’s skin is so very thin that it uses it to breath thru, to help out its poor little lungs, just as the frogs and other water creatures which have lungs breath thru the skin also. You know the size of baby I mean; if you haven’t had any younger brothers and sisters, there must at least have been something like it in the next house.

Now there are several very strange facts about such little babies, of which by no means the least strange is this: If you take such a very weak and tiny creature, just able to move its arms and legs, and put a finger or a small stick across the palm of its hand, the little one will grip so hard that you will have no small difficulty in getting its fingers loose again. In fact, some babies will actually allow themselves to be lifted in this way; and will hang by their hands a minute or more before they will flop down again into a helpless heap.

So here is one thing that the wee baby can do better than he can when he gets to be older and a good deal stronger, and better sometimes than he will ever be able to do it again. It is something, too, that he did the first time he tried, didn’t have to learn, didn’t have to practice, didn’t have to do anything but just be born knowing how. Pity we can’t all get our geography lessons and our piano practice done this easy way!

There are not a few other things which we all did exactly right the first time, without ever being shown how, or practicing, or seeing anyone else. For instance, when we were very young indeed, and very small, about as young and small, in fact, as people ever get, somebody gave us our first drink of water. We were not a day old then; and we didn’t even know enough to look at the same point with both eyes at once, but let them straggle off, one eye looking at one thing and the other at another, so that both got generally mixed up and couldn’t make out much of anything. But we knew all about drinking. We shut our little mouths tight round the stopper of our bottle, and sucked away like little steam pumps. The water went down the front of our throats, crossed over to the back, and went into our thirsty tummies. Meanwhile, our breath went in at our noses, down into the back of our throats, crossed over to the front, and went down our wind-pipes. But tho wind and water had to go crosswise of the same passage, we never made a mistake, and opened or shut the wrong lid for the wrong fluid, so as to let the air into our stomachs or the water into our lungs. Which really, when you consider how young we were, and how this was the first drink we ever took, was decidedly clever of us.

An act of this sort, which we are born knowing how to do and do right the first time without ever practising or being taught, is called an instinct. Mighty handy, too, they are, these instincts. Think what would happen to a baby that didn’t have the sucking instinct, and couldn’t take a spoonful of water nor a drop of milk till somebody had explained about drinking and showed him how to swallow without letting it run down the wrong way. I don’t believe there would be much chance of that baby’s ever growing up. To be sure, the other instinct that makes the little baby grip so hard on one’s finger, really, isn’t any particular use to him in these days. Long, long ago, nevertheless, when our ancestors were wild men and only half human, the little baby had to cling to its mother when she ran thru the forest with the wild beasts chasing her. Then if the little baby couldn’t hang on tight, it was pretty likely to get eaten up. But the babies that clung to their mothers, while their mothers were climbing a tree with both hands, and so couldn’t hold on to them, these babies lived to grow up, and the memory of that far away time still lingers in each little baby’s grip.

Some things are so important that one really has to know them. Did you ever think why girls like to play with dolls and boys do not? Why, on the other hand, boys can throw stones and girls cannot? Girls like to play with dolls, because when they grow up to be women and have real babies of their own, these babies have got to be dressed and fed and washed and tended and taken care of when they are sick. All this is very hard work indeed, about as hard and trying work as anybody ever has to do; so that if your own particular mama did not have a natural and instinctive love in her heart for all babies, she would not have jumped up at night every time you cried, no matter how cold and sleepy she was. If taking care of little babies were just plain work, to be done no better than other sorts of work are done, it would be pretty unpleasant for the babies. So women are made to love babies so much that even when they are little girls they like to play at taking care of doll babies, in default of real ones. But boys and men, they don’t count; so they do not have this taking-care-of-babies-and-dolls instinct.

But the boys and men can throw things, because before the invention of guns (which really was not very long ago) and before men lived in cities and planted crops, about the only way to get anything to eat was to get out and throw something at an animal and kill it. Then, too, when there was a war (and this often used to be most of the time) the fighting had to be done with spears and swords, which had to be thrown, or else used to strike and thrust with, which is pretty much the same thing as throwing. So it happened that for ages upon ages before our ancestors became civilized, while the women stayed at home and took care of the children, the men went out and threw things. And that is why today, girls like to play with dolls, but boys like to hunt and fish; and why boys can throw stones, and girls can’t.

Boys, then, are born with the throwing instinct. Throwing is as easy for them to learn as walking. But girls haven’t it. For them learning to throw is as hard as learning to walk on the hands. So we see how both with walking and throwing, the inborn instinct makes learning easy, tho it does not altogether take the place of practice.

XIII

Why We Like Certain Things

We have seen that the reason why all proper little girls like to play at taking care of dolls is that their mothers, and their grandmothers, and their great-grandmothers, and their great-great-grandmothers, and all other sizes of grandmothers for a thousand generations, and after that for another thousand, and after that nobody knows how many more, have all been taking care of real babies, until anything that looks like a baby has become about the most interesting and precious thing there is. We have seen also that boys learn to throw things easily, and like to throw things because all the while that their many times great-grandmothers have been taking care of the children, their many times great-grandfathers have been throwing spears and javelins at other people’s ancestors, or at things to eat running about on four legs.

Every proper boy likes to hunt and fish and camp out and play Indian because the most of mankind, up to a few centuries ago, have spent their entire time in hunting, fishing, living in huts, and generally playing Indians. Indians themselves, of course, play Indians all the time; and up to the beginning of the Christian era, our own ancestors, living in the wilds of northern Europe, were about as wild as Indians, and did little except play Indians all their lives. Who knows but that, a thousand years from now, after men have been civilized for a long while, and been getting their livings many years standing at benches or sitting at desks, all proper boys will think it great fun to study out of a book indoors? Perhaps they may; but I think it will be a long time first!

Every proper boy, too, when he gets old enough (and that is not so very old) likes to play at games. Now pretty much all these games, when you come to think of it, baseball, cricket, hockey, tennis, golf, I don’t know how many more, all involve hitting a ball with a stick. If we like to throw balls with our hands because our wild forebears threw javelins and spears with theirs, can you not guess at once that the reason why we like to strike balls with sticks is that these same wild forebears had for so many ages been striking things with clubs and swords? We like what our ancestors had to do. If we cannot cut and thrust and hack and throw and strike at wild animals in the chase or at other men in battle, at least we can do it with a ball. So bat and ball are the boy’s dolls. He plays with them for the same excellent reason that his sister plays with hers.