Читать книгу Trees, Shown to the Children - C. E. Smith - Страница 7

DEAR CHILDREN,—In this little book I have written about some of the trees which you are likely to find growing wild in this country, and Miss Kelman has painted for you pictures of these trees, with drawings of the leaves and flowers and fruit, so that it will be easy for you to tell the name of each tree. But I think there is one question which you are sure to ask after reading this small book, and that is, “How do the trees grow?”

The tree grows very much as we do, by taking food and by breathing. The food of the tree is obtained from two sources: from the earth and from the air. Deep down in the earth lie the tree roots, and these roots suck up water from the soil in which they are embedded. This water, in which there is much nourishment, rises through many tiny cells in the woody stem till it reaches the leaf, twigs, and green leaves. As it rises the growing cells keep what they need of the water. The rest is given off as vapour by the leaves through many tiny pores, which you will not be able to see without a microscope.

While it is day the green leaves select from the air a gas called carbonic acid gas. This they separate into two parts called oxygen and carbon. The plant does not need the oxygen as food, so the leaves return it to the air, but they keep the carbon. This carbon becomes mixed in some strange way with the water food drawn from the soil by the roots. Forming a liquid, it finds its way through many small cells and channels to feed the growing leaves and twigs and branches.

But, like ourselves, a tree if it is to live and thrive must breathe as well as take food. By night as well as by day the tree requires air for breathing. Scattered over the surface of the leaves, and indeed over the skin of the tree, are many tiny mouths or openings called stomata. It is by these that the tree breathes. It now takes from the air some oxygen, which, you will remember, is the gas that the leaves do not need in making their share of the tree food. Now you can see why it is that a tree cannot thrive if it is planted in a dusty, sooty town. The tiny mouths with which it breathes get filled up, and the tree is half-choked for lack of air. Also the pores of the leaves become clogged, so that the water which is not needed cannot easily escape from them. A heavy shower of rain is a welcome friend to our dusty town trees.

As a rule tree flowers are not so noticeable as those which grow in the woods and meadows. Often the ring of gaily-coloured petals which form the corolla is awanting, so are the green or coloured sepals of the calyx, and the flower may consist, as in the Ash tree, of a small seed-vessel standing between two stamens, which have plenty of pollen dust in their fat heads.

It is very interesting to notice the various ways in which the tree flowers grow. In some trees the stamens and seed-vessels will be found close together, as in the Ash tree and Elm. Or they may grow on the same branch of a tree; but all the stamens will be grouped together on one stalk and all the seed-vessels close beside it on another stalk, as in the Oak tree. Or the stamen flowers may all be found on one tree without any seed flowers, and on another tree, sometimes a considerable distance away, there will be found nothing but seed flowers. This occurs in the White Poplar or Abele tree.

You must never forget that both kinds of flowers are required if the tree is to produce new seed, and many books have been written to point out the wonderful ways in which the wind and the birds and the bees carry the stamen dust to the seed-vessels, which are waiting to receive it.

Each summer the tree adds a layer of new wood in a circle round the tree trunk; a broad circle when there has been sunshine and the tree has thriven well, and a narrow circle when the season has been wet and sunless. This new layer of wood is always found just under the bark or coarse, outer skin of the tree. The bark protects the soft young wood, and if it is eaten by cattle, or cut off by mischievous boys, then the layer of young wood is exposed, and the tree will die.

When winter approaches and the trees get ready for their long sleep, the cells in this layer of new wood slowly dry, and it becomes a ring of hard wood. If you look at a tree which has just been cut down, you will be able to tell how many years old the tree is by counting the circles of wood in the tree trunk. When a tree grows very slowly these rings are close and firm, and the wood of the tree is hard and valuable.

Many, many years ago, when a rich Scotch landlord lay dying, he said to his only son, “Jock, when you have nothing else to do, be sticking in a tree; it will aye be growing when you are sleeping.” He was a clever, far-seeing old man, Jock’s father, for he knew that in course of time trees grow to be worth money, and that to plant a tree was a sure and easy way of adding a little more to the wealth he loved so dearly.

But a tree has another and a greater value to us and to the world than the price which a wood merchant will give for it as timber. Think what a dear familiar friend the tree has been in the life of man! How different many of our best-loved tales would be without the trees that played so large a part in the lives of our favourite heroes. Where could Robin Hood and his merry men have lived and hunted but under the greenwood tree? Without the forest of Arden what refuge would have sheltered the mischief-loving Rosalind and her banished father? How often do we think of the stately Oak and Linden trees into which good old Baucis and Philemon were changed by the kindly gods.

And do you remember what secrets the trees told us as we lay under their shady branches on the hot midsummer days, while the leaves danced and flickered against the blue, blue sky? Can you tell what was the charm that held us like a dream in the falling dusk as we watched their heavy masses grow dark and gloomy against the silvery twilight sky?

In a corner of a Cumberland farmyard there grew a noble tree whose roots struck deep into the soil, and whose heavy branches shadowed much of the ground. “Why do you not cut it down?” asked a stranger; “it seems so much in the way.” “Cut it down!” the farmer answered passionately. “I would sooner fall on my knees and worship it.” To him the tree had spoken of a secret unguessed by Jock’s father and by many other people who look at the trees with eyes that cannot see. He had learned that the mystery of tree life is one with the mystery that underlies our own; that we share this mystery with the sea, and the sun, and the stars, and that by this mystery of life the whole world is “bound with gold chains” of love “about the feet of God.”

C. E. SMITH.