LESSON VII.
SEEDS AND LEAVES.
TREASURE-BOXES.
TREASURE-BOXES.
The seed is the egg of the plant. Just as the new chick is in the egg of the hen, or the new wasp is in the egg of the wasp, the new plant is in the seed.
Let us look at a hen’s egg. It has a shell. Inside the shell is the clear white. Inside the white is the yellow ball, or yolk. The shell keeps the white and yolk safe. The white and yolk of the egg make the food by which the chick lives and grows,before it is hatched. In the yolk you may see a tiny spot, which is the germ out of which the young chick will grow.
The eggs of all birds and insects vary little from this plan. The flower-seed is also an egg made on this same pattern.
The skin you saw on the bean serves for the shell. There is an inner skin often, like the silken skin inside the egg-shell. The food stored up in the seed-leaves serves as the yolk and white of the egg. The tiny germ between answers to the spot in the yolk, which is the chick germ.
The seeds of flowers differ more than the eggs of birds and insects. For some seeds have no coats at all. Some have only one. But in this lesson we speak of seeds as they commonly are. We tell you of seeds as you are likely to see them. The rarer things you must learn in larger books.
Let us look at seeds a little. Think how they differ in size. A great cocoanut is a very huge seed. If you ask your mother to show you her garden-seeds, you will find some as small as the finest grains of dust.
Seeds vary in color. Did any one ever give you a little round, bright India bean? It was red as a drop of blood. It had a jet black mark on one side.
If you look in the grocer’s window, you will see yellow peas and green ones. You will see beans,—black, white, brown, yellow, purple, and spotted. Some of the garden-seeds are purple. Some look like the filings of steel, or silver, or gold.
Seeds vary in shape. You know how acorns and chestnuts look; they are seeds. Cherry-pits—stones, you call them, they are so hard—are round. A melon-seed is flat. Some seeds are three-cornered. Some have lines and dots as if they were carved.
Some seeds have little hooks on them to hold them to the ground so that they may not blow away. Other seeds use these hooks to catch upon things, that will carry them from place to place.
Did you ever see a thistle or dandelion seed go sailing through the air? It looks like a little silver ship, or balloon. It has a fine little feather on it to keep it up. The reason why thistles and dandelions grow far and wide is, that their seeds are carried about on the breeze.
If you live in town, go and look at the seeds in the seed-man’s window. If you live in the country, suppose you collect all the seeds you can.
Did you ever think in how many ways seeds are kept from harm? What is a melon, or a pumpkin, but a big seed box?
“Oh!” you say, “melons and pumpkins are good to eat!” So they are, the better luck for us, that is. But all the plant wants of these big things, is to hold the precious seed.
An apple is a nice fleshy case to hold the seeds in the core. The cherry and plum are softer seed bags, which hold hard pits.
Did you ever look at a blackberry? You saw it was made up of little balls or knobs. Each of these soft, sweet knobs holds a tiny seed. A strawberry is quite different. The strawberry is a sweet red cone. Look, it is sprinkled all over with little yellow dots! Each of these dots is a seed.
I will tell you a little about the “why” of all this, in some other lesson.
You see the seed is that without which the plant cannot make a new plant. Without seeds there would soon be no more plants.
The leaves are those parts without which the plant cannot live and grow. But I think I hear some sharp child say, “How about those plants that have no leaves?”
In the few plants that have no leaves, the stem may help to serve in their place. But most of the few plants that have no leaves fasten upon other plants, and grow upon them. They use the leaves of those other plants to do their work.
In these simple lessons, I tell you of only common things. I speak of the things that you can see each day. For the rare things you must go to larger books.
You know from your last lessons that leaves are the stomach of the plant. Leaves are also the plant’s lungs.
Plants must breathe. They must breathe in and out, as you do. Also the plants must get rid of the water which they do not need after they have taken the food out of it. Much of this water passes out through the leaves.
You know when you are very warm, you feel a moisture come on your skin. That was once water in your blood. It creeps out through tiny pores over all your skin.
The plant skin has such pores. The water goes off through them. When the plant breathes out this water, then more hurries up through the cells to take its place. So the sap keeps running up and down all the time.
Plants not only send out water through the pores of the leaves, but also a kind of air or gas. If they did not do that, we should soon all be dead. Can I make that plain to you?
Did you ever hear your mother say, “The air here isbad or close”? Did you ever see your teacher open a door or a window, to “air” the schoolroom? If you ask why, you will be told “So many people breathing here make the air bad.”
How does our breathing make the air bad? When our blood runs through our bodies it takes up little bits of matter that our bodies are done with. This stuff makes the blood dark and thick. But soon the blood comes around to our lungs.
Now as we breatheout, we send into the air the tiny atoms of this waste stuff. It is carbonic acid gas. As we breathein, we take from the fresh air a gas called oxygen. That goes to our lungs, and lo! it makes the blood fresh and clean, and red once more.
So you can see, that when many people breathe in one room they will use up all the good clean air. At the same time they will load the air of the room with the gas they breathe out.
That is why the window is opened. We wish to sweep away the bad air, and let in good air.
But at this rate, as all men and other animals breathe out carbonic acid gas, why does not all the air in the world get bad? Why, when they all use oxygen, do they not use up all the oxygen that is in the world?
Just here the plants come in to help. Carbonic acid gas is bad for men, it is food to plants. Oxygen is needed by animals, but plants want to get rid of it. Animals breathe out a form of carbon and breathe in oxygen. Plants do just the other thing. They breathe out oxygen and take in carbonic acid gas.
The air, loaded with this, comes to the plant. At once all the little leaf-mouths are wide open to snatch out of the air the carbonic acid gas. And, as the plants are very honest little things, they give where they take away. They take carbon from the air, and breathe into the air a little oxygen.
Where did they get that? The air they breathe has both carbon and oxygen in it. So they keep what they want,—that is, carbon,—and send out the oxygen.
Now it is only the green part of the plant that does this fine work for us. It is the green parts, chiefly the leaves, that send out good oxygen for us to breathe. It is the green leaf that snatches from the air those gases which would hurt us.
It is the green leaf that changes the harmful form of carbon into good plant stuff, which is fit for our food. How does it do that? Let us see.
What makes a leaf green? Bobby who crushed a leaf to see, told me “a leaf was full of green paint.”
Inside the green leaves is a kind of green paste, or jelly. Now it is this “leaf-green” that does all the work. The “leaf-green” eats up carbon. The “leaf-green” turns carbon into nice safe plant material. It is “leaf-green” that sets free good oxygen for us.
“Leaf-green” is a good fairy, living in every little cell in the leaf. Leaf-green is a fairy which works only in the day-time. Leaf-green likes the sun. Leaf-green will not work in the dark, but goes to bed and goes to sleep!
In such simple lessons as these, I can tell you only a little of whatis. The deep “how” and “why” of things I cannot explain. Even the very wisest men do not know all the how and the why of the “leaf-green” fairy.
I have told you these few things that you may have wonders to think of when you see green leaves. After this lesson, will you not care more for seeds and leaves than you ever did before?