LESSON X.
PLANTS AND THEIR PARTNERS.
Did I not tell you that the plants had taken partners and gone into business? I said that their business was seed-growing, but that the result of the business was to feed and clothe the world.
In our first lessons we showed you that we get all our food, clothes, light, and fuel, first or last, from plants. “Stop! stop!” you say. “Some of us burn coal. Coal is a mineral.” Yes, coal is a mineral now, but it began by being a vegetable. All the coal-beds were once forests of trees and ferns. Ask your teacher to tell you about that.
THE THREE PARTNERS.
THE THREE PARTNERS.
If all these things which we need come from plants, we may be very glad that the plants have gone into business to make more plants.
Who are these partners which we told you plants have? They are the birds and the insects. They might have a sign up, you see, “Plant, Insect & Co., General Providers for Men.”
Do let us get at the truth of this matter at once! Do you remember whatyou read about the stamens and pistils which stand in the middle of the flower? You know the stamens carry little boxes full of pollen. The bottom of the pistil is a little case, or box, full of seed germs.
You know also that the pollen must creep down through the pistils, and touch the seed germs before they can grow to be seeds. And you also know, that unless there are new seeds each year the world of plants would soon come to an end.
Now you see from all this that the stamens and pistils are the chief parts of the flower. The flower can give up its calyx, or cup, and its gay petals, its color, honey, and perfume. If it keeps its stamens and pistils, it will still be a true seed-bearing flower.
It is now plain that the aim of the flower must be to get that pollen-dust safely landed on the top of the pistil.
You look at a lily, and you say, “Oh! that is very easy. Just let those pollen boxes fly open, and their dust is sure to hit the pistil, all right.”
But not so fast! Let me tell you that many plants do not carry the stamens and pistils all in one flower. The stamens, with the pollen boxes, may be in one flower, and the pistil, with its sticky cushion to catch pollen, may be in another flower.
More than that, these flowers, some with stamens, and some with pistils, may not even be all on one plant! Have you ever seen a poplar-tree? The poplar has its stamen-flowers on one tree, and its pistil-flowers on another. The palm-tree is in the same case.
Now this affair of stamen and pistil and seed making does not seem quite so easy, does it? And here is still another fact. Seeds are the best and strongest, and most likely to produce good plants, if the pollen comes to the pistil, from a flower not on the same plant.
This is true even of such plants as the lily, the tulip, and the columbine, where stamens and pistils grow in one flower.
Now you see quite plainly that in some way the pollen should be carried about. The flowers being rooted in one place cannot carry their pollen where it should go. Who shall do it for them?
Here is where the insect comes in. Let us look at him. Insects vary much in size. Think of the tiny ant and gnat. Then think of the great bumble bee, or butterfly. You see this difference in size fits them to visit little or big flowers.
You have seen the great bumble bee busy in a lily, or a trumpet flower. Perhaps, too, you have seen alittle ant, or gnat, come crawling out of the tiny throat of the thyme or sage blossom. And you have seen the wasp and bee, busy on the clover blossom or the honeysuckle.
Insects have wings to take them quickly wherever they choose to go. Even the ant, which has cast off its wings,[9]can crawl fast on its six nimble legs.
Then, too, many insects have a long pipe, or tongue, for eating. You have seen such a tongue on the bee.[10]In this book you will soon read about the butterfly, with its long tube which coils up like a watch spring.
With this long tube the insect can poke into all the slim cups, and horns, and folds, of the flowers of varied shapes.
Is it not easy to see that when the insect flies into a flower to feed, it may be covered with the pollen from the stamens? Did you ever watch a bee feeding in a wild rose? You could see his velvet coat all covered with the golden flower dust.
Why does the insect go to the flower? He does not know that he is needed to carry pollen about. He never thinks of seed making. He goes intothe flower to get food. He eats pollen sometimes, but mostly honey.
In business, you know, all the partners wish to make some profit for themselves. The insect partner of the flower has honey for his gains. The flower lays up a drop of honey for him.
In most flowers there is a little honey. Did you ever suck the sweet drop out of a clover, or a honeysuckle? This honey gathers in the flower about the time that the pollen is ripe in the boxes. Just at the time that the flower needs the visit of the insects, the honey is set ready for them.
Into the flower goes the insect for honey. As it moves about, eating, its legs, its body, even its wings, get dusty with pollen. When it has eaten the honey of one flower, off it goes to another. And it carries with it the pollen grains.
As it creeps into the next flower, the pollen rubs off the insect upon the pistil. The pistil is usually right in the insect’s way to the honey. The top of the pistil is sticky, and it holds the pollen grains fast. So here and there goes the insect, taking the pollen from one flower to another.
But stop a minute. The pollen from a rose will not make the seed germs of a lily grow. The tulip can do nothing with pollen from a honeysuckle.The pollen of a buttercup is not wanted by any flower but a buttercup. So of all. The pollen to do the germ any good must come from a flower of its own kind.
What is to be done in this case? How will the insect get the pollen to the right flower? Will it not waste the clover pollen on a daisy?
Now here comes in a very strange habit of the insect. Insects fly “from flower to flower,” but they go from flowers of one kind to other flowers of thesame kind. Watch a bee. It goes from clover to clover, not from clover to daisy.
Notice a butterfly. It flits here and there. But you will see it settle on a pink, and then on another pink, and on another, and so on. If it begins with golden rod, it keeps on with golden rod.
God has fixed this habit in insects. They feed for a long time on the same kind of flowers. They do this, even if they have to fly far to seek them. If I have in my garden only one petunia, the butterfly which feeds in that will fly off over the fence to some other garden to find another petunia. He will not stop to get honey from my sweet peas.
Some plants have drops of honey all along up the stem to coax ants or other creeping insects up into the flower.
But other plants have a sticky juice along the stem, to keep crawling insects away. In certain plants the bases of the leaf-stems form little cups, for holding water. In this water, creeping insects fall and drown.
Why is this? It is because insects that would not properly carry the pollen to another flower, would waste it. So the plant has traps, or sticky bars, to keep out the kind of insects that would waste the pollen, or would eat up the honey without carrying off the pollen.
I have not had time to tell you of the many shapes of flowers. You must notice that for yourselves.
Some are like cups, some like saucers, or plates, or bottles, or bags, or vases. Some have long horns, some have slim tubes or throats. Some are all curled close about the stamens and pistils.
These different kinds of flowers need different kinds of insects to get their pollen. Some need bees with thick bodies. Some need butterflies with long, slim tubes. Some need wasps with long, slender bodies and legs. Some need little creeping ants, or tiny gnats.
Each kind of flower has what will coax the right kind of insects, and keep away the wrong ones. What has the plant besides honey to coax the insect fora visit? The flower has its lovely color, not for us, but for insects. The sweet perfume is also for insects.
Flowers that need the visits of moths, or other insects that fly by night, are white or pale yellow. These colors show best at night. Flowers that need the visits of day-flying insects, are mostly red, blue, orange, purple, scarlet.
There are some plants, as the grass, which have no sweet perfume and no gay petals. I have told you of flowers which are only a small brown scale with a bunch of stamens and pistils held upon it. And they have no perfumes. These flowers want no insect partners. Their partner is the summer wind! The wind blows the pollen of one plant to another. That fashion suits these plants very well.
So, by means of insect or wind partners, the golden pollen is carried far and wide, and seeds ripen.
But what about the bird partners? Where do they come in?
If the ripe seed fell just at the foot of the parent plant, and grew there, you can see that plants would be too much crowded. They would spread very little. Seeds must be carried from place to place. Some light seeds, as those of the thistle, have a plume. The maple seeds have wings. By these the wind blows them along.
But most seeds are too heavy to be wind driven. They must be carried. For this work the plant takes its partner, the bird.
To please the eye of the bird, and attract it to the seed, the plant has gay-colored seeds. Also it has often gay-colored seed cases. The rose haws, you know, are vivid red. The juniper has a bright blue berry. The smilax has a black berry. The berries of the mistletoe are white, of the mulberry purple.
These colors catch the eye of the bird. Down he flies to swallow the seed, case, and all. Also many seed cases, or covers, are nice food to eat. They are nice for us. We like them. But first of all they were spread out for the bird’s table.
Birds like cherries, plums, and strawberries. Did you ever watch a bird picking blackberries? The thorns do not bother him. He swallows the berries fast,—pulp and seed.
You have been told of the hard case which covers the soft or germ part of the seed, and its seed-leaf food. This case does not melt up in the bird’s crop or gizzard, as the soft food does. So when it falls to the ground the germ is safe, and can sprout and grow.
Birds carry seeds in this way from land to land, aswell as from field to field. They fly over the sea and carry seeds to lonely islands, which, but for the birds, might be barren.
So by means of its insect partners, the plant’s seed germs grow, and perfect seeds. By means of the bird partners, the seeds are carried from place to place. Thus many plants grow, and men are clothed, and warmed, and fed.
FOOTNOTES:[9]See Nature Reader, No. 2, Lessons on Ants.[10]No. 1, Lesson 18.
[9]See Nature Reader, No. 2, Lessons on Ants.
[9]See Nature Reader, No. 2, Lessons on Ants.
[10]No. 1, Lesson 18.
[10]No. 1, Lesson 18.