Part 4

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 into the 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 the _same 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 for a 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, as well 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.

LESSON XI.

AIR, WATER, AND SAND PLANTS.

Most of the plants which you see about you grow in earth or soil. You have heard your father say that the grass in some fields was scanty because the soil was poor. You have been told that wheat and corn would not grow in some other field, because the soil was not rich enough.

You understand that. The plant needs good soil, made up of many kinds of matter. These minerals are the plant’s food. Perhaps you have helped your mother bring rich earth from the forest, to put about her plants.

But beside these plants growing in good earth in the usual way, there are plants which choose quite different places in which to grow. There are air-plants, water-plants, sand-plants. Have you seen all these kinds of plants?

You have, no doubt, seen plants growing in very marshy, wet places, as the rush, the iris, and the St. John’s-wort. Then, too, you have seen plants growing right in the water, as the water-lilies, yellow and white; the little green duck-weed; and the water crow-foot.

If you have been to the sea-shore, you have seen green, rich-looking plants, growing in a bank of dry sand. In the West and South, you may find fine plants growing in what seem to be drifts, or plains of clear sand.

Air-plants are less common. Let us look at them first. There are some plants which grow upon other plants and yet draw no food from the plant on which they grow. Such plants put forth roots, leaves, stems, blossoms, but all their food is drawn from the air.

I hope you may go and see some hot-house where orchids are kept. You will see there splendid plants growing on a dead branch, or some other dry thing, high up in the air.

Did you ever see a piece of mistletoe? It grows on some tree. It has nice green leaves and white berries. That the mistletoe draws all its food from the air has been proved. It thrives as well on a dead tree as on a live one. A Frenchman, who loved to study plants, made a mistletoe plant grow on a cannon ball. Another mistletoe sprouted and grew from a seed held out on the point of a copper needle.

Thus, you see, these air-plants gain all their food from the air.

Water-plants will seem to you to grow in a more natural way. Most of them are rooted in the earth at the bottom of the pond, or ditch, where they grow. As the blossoms form, the flower stem grows long, and the flower rises to the top of the water.

There the lovely blossom floats about in the sunshine. It is moored by its long stem to the root, as a boat is moored by a rope. When the seeds are ripe, the flower stem sinks down again. The leaf stems rise to the top of the water. There the leaves lie spread out, to breathe the air.

Now when these leaves of water-plants are made to grow to the top of the water and live, they are broad, and often shaped like a shield. They are to spread out on the surface of the water, and catch all the air and sunshine that they can.

But there are other kinds of water-plants which have their leaves growing down under the water. All these leaves made to stay in the water are fringe-like and narrow. They look like wide leaves cut into many small strips.

Most sea-weeds have fringe-like leaves. Yet there are sea-weeds with wide leaves. They, like the fish, are made to live in the water all the time.

The fresh-water plants generally mean to come to the top of the water some time. They have green leaves. Their leaves can keep green only by the action on them of the air and light. This is why the leaf is made fringe-like. Its fringed leaves act as a net, floating around in the water. These leaf-nets catch not fish, but air-bubbles, and rays of light.

The water crow-foot, or water buttercup, has two kinds of leaves. Those at the bottom of the stalk are all in fine fringes. The leaves at the top are broad, like other crow-foot leaves.

There are some water-plants which do not root at the bottom of the pond. They spend all their lives floating about. A little plant called “duck-weed” is one of them. It has a soft, green body like two halves of a tiny pea. Its roots are three or four fine threads. It gathers all its food from the water.

Most water-plants have two sets of roots. One set holds the plant fast in its place. The other roots spring from the base of the leaves. They gather food from the water.

Now, while leaves that grow in the water are fringe-like, I think you will see that leaves of plants that grow in sand must be just the opposite.

If you examine a plant growing in dry sand, you will find that it has thick, soft, juicy leaves. The leaves of sand-plants are seldom flat. They are shaped like fringes, or the palm of your hand, or like little rolls.

Why is that? Can you not guess? The roots of these sand-living plants can get very little water. Only when rain and heavy dew fall can they get moisture. If they are wise little plants, they will store moisture up.

These sand-plants store up food and moisture in their leaves. It may surprise you that plants, growing in such dry places, have leaves so full of juice. The leaves are their pantry. They are full of saved-up water.

You will notice another thing. Many of the sand-plants have their leaves covered with prickles, hooks, and thorns. The leaves are rough, like burrs. Why is that? Is it not so, that birds and beasts will not want to eat them?

If the leaves are nipped off by animals, these plants must die. Their sand home gives them no water for their roots. If the leaves are eaten, all the plant must perish.

As there is so little water in the sand to carry food to the plant through the roots, the leaves of these plants must do most of their eating. So in the sand-growing plants the leaves serve as mouth, stomach, and pantry.

By the sea-side you will find plenty of sand-growing plants. You can study them, and prove these points for yourselves.

Children who are not by the sea may, perhaps, have, near where they live, a curious sand-loving plant, the cactus. The cactus prefers a sandy soil. I have seen a large cactus, covered with yellow blooms, growing right in a drift of clear sand.

You will notice that what you call the leaves of the cactus are not real leaves, but thick, odd-shaped stems. These stems are green, and answer for leaves. They are of many queer shapes. They are covered with little clusters of prickles. As they serve for leaves, these odd stems of a sand-plant are fleshy and juicy. The plant stores its food and drink in them.

LESSON XII.

PLANTS THAT EAT ANIMALS.

You have now heard of so many wonders about plants, that perhaps nothing new which you will hear of them will surprise you. You may not even say “Oh!” when I tell you that some plants eat bugs,--as ants, gnats, and flies,--and will not even refuse a nice bit of raw meat!

These plants are called the “flesh-eaters.” The name is a long one,--carnivora. Here is a verse about them. As it has long, hard words in it, I wish to say I did not make it.

“What’s this I hear About the new carnivora? Can little plants Eat bugs and ants? Why this is retrograding! Surely the fare Of flowers is air, Or sunshine sweet. They should not eat, Or do aught so degrading.”

These animal-eating plants are so made that they catch insects, and suck up, or draw out, the juice of their bodies. This juice the plant seems to feed upon. It has been seen to pass from the leaf which catches the insect into the stem and other parts of the plant.

In all these insect-eating plants, it is the leaf that does the killing and eating.

I will first tell you of a little water-plant of this queer class. It is called the bladder-plant. It is one of the water-plants which float free. On the fringe-like leaves are little bags or bladders. These are full of air, and help the plant to float. The mouth of these little bags has a door opening inward. It is set round with hairs.

The little insect-larvæ which live in water, and other tiny animals that swim about, see these little floating bags, with the small, green doors. The creatures act as if they wanted to know what was inside such pretty places. Finally they go in. To go in is easy. But once in, they cannot get out. The little door will not open outwards.

After a day or two, the animal thus trapped is all eaten. Only the hard, horny parts, which serve for its bones, are left.

There is another small plant, called the sun-dew, which eats insects. Any of you who live near a cranberry bog can find sun-dew growing on the edges of the bog. It is a plant that lives in wet places.

The sun-dew has a number of leaves about the size and shape of pearl shirt-buttons. They grow on short stems close to the ground. The leaves are covered with red hairs. These hairs are called tentacles. As many as a hundred and fifty will grow on one little leaf.

From these long, red hairs come tiny drops of sticky stuff. These drops gleam like dew. From them, and the little red, hairy rays, the plant has its name.

The insect comes flying by. The “dew” looks like something good to eat. But as soon as the insect touches the leaf, the juice holds its legs fast. The insect begins to kick, but cannot get away.

The struggles of the insect seem to irritate the plant. For, when the hairs are touched, they pour out more juice. Not only this, but the touch of the insect on the hairs causes the leaf to bend upwards. It bends over, over, folding down, until it is all shut up upon the insect.

Here is the insect held in the folded leaf. The glue runs out over it faster than ever. When you think how the insect breathes through tubes wound over all its body,[11] you will see that it must soon smother, held in this sticky juice.

When the leaf is bent over the insect, the juice changes. When the leaf is so bent, the juice is acid, or sour. This acid juice melts up the body of the insect. As it melts, the mouths, or glands, of the leaf seem to suck it up.

The sun-dew will melt up and devour bits of meat laid on the leaf. Water-drops on the leaf will not make it bend. But when milk-drops are put on the leaf, it bends, and sucks them up.

The leaf will not close over a piece of stone, or glass. But it will close over a bit of boiled egg, or a scrap of bone. It melts the bone so soft, that you can stick a needle into it.

Another animal-eating plant is the Venus’s-flytrap. It grows only in North Carolina. The leaf-blade has sharp bristles about the upper part. Each half of the leaf hollows a little, so that when the two halves come together they form a small pouch.

The leaf has some fine hairs which an insect cannot but touch, when it moves on the leaf. When the hairs are touched, the leaf bends. The bristles on the edges lock together, so that the insect is held in a cage, even before the leaf closes.

When the leaf is fully closed, the insect is held in a bag prison. The glands then pour out juice to melt up the body of the insect. As it melts, its juices are drawn into the plant.

The Venus’s-flytrap does not seem to depend alone on the chance lighting of the insect upon it. It has a sweet juice on the leaf to attract insects. But it does not need as much sticky fluid as the sun-dew, to hold the insect. The two halves of the leaf snap together like a trap. They give the insect no time to get away.

Another very odd plant which eats insects is the side-saddle plant. This is often called the pitcher-plant. It looks far more like a pitcher than like a saddle. The leaves of this plant are like a beautiful pitcher painted red and green.

These plants are common in the South. They grow also in marshy places in the North. I remember how happy I was when my father brought me three of them, when I was a little girl.

There are two or three kinds of these pitcher-plants. One kind is green, spotted with red, and has some yellow lines. Another kind is green with purple marks. You must notice that the inner side of the lid is of the brightest color.

Why is this? Insects see the gay color and fly to the plant. The leaves of the pitcher-plant are large, and they are bent and the edges grow together nearly all the way up. This forms a close pitcher which will hold water.

The seam where the leaves are joined is usually of a light yellow color. It is covered with a honey-like juice, in small drops. The rim of the pitcher and the inside of the neck have also these honey drops.

The insects, attracted by the gay color, come to feed on the honey. They feed along the seam and rim, and so into the throat of the pitcher. They seem to get dizzy, or so full of honey, that they feel dull. They get down into the pitcher, and--there they stay!

Why do they not come out? For three reasons. The inside of the pitcher has a band of hairs growing downward. The insects cannot creep up through these. The hairs turn them back, as a brush fence turns cattle.

Then, too, part of the inside of the pitcher is so smooth that insects fall back when they walk on it. Still, as they can walk on glass, I think their slipping back must be due more to being dizzy, than to the smooth surface.

And here is the third reason, the pitcher is half full of liquid, and this liquid seems to make the insect dizzy. This liquid looks like pure, clear water. It tastes like the root of the plant,--a biting taste.

It is not like the honey-dew which lies on the seam for a bait. In this liquid, inside, the insects are drowned.

You may find many dead insects in one pitcher. I told you a little about this, in the last book, in the lessons on flies.[12] The dead bodies of the insects melted up seem to help to feed the plant. But often a pitcher catches more insects than the plant can use.

There are many kinds of pitcher-plants in very warm lands. You may be able to see some of them in hot-houses. All have the same general way of killing and eating insects.

FOOTNOTES:

[11] See Nature Reader, No. 2, p. 77.

[12] Nature Reader, No. 2, pp. 59-60.

LESSON XIII.

WEATHER PROPHET PLANTS.

Once, when I was a little girl, I ran one morning to the garden, and said to the old Scotchman who worked there, “To-day I am going up the mountain for berries.”

“No, no, Missey, not to-day,” he said; “it will rain.” “No, it will not rain,” I said. “The sun is up. The cook says it will be fair. The glass in the hall does not say rain.”

“Tuts, tuts,” said the old man. “I care for no suns, or cooks, or glasses. The pimpernel says it will rain, and so it _will_ rain. Flowers, Missey, always tell the truth. When they say ‘rain,’ go, get your umbrella.”

Sure enough, by noon, the rain was pouring down. After that, I looked with great respect at the tiny flower, sometimes brick red, sometimes blue, which could tell about the weather.

But the pimpernel is not the only plant that is a weather prophet. We will look first at some plants, and then at some seeds, which tell about the weather.

If you go into the garden, and find the African marigold shut, after seven o’clock in the morning, you may be pretty sure that there will be a rainy day.

But while the African marigold stays shut for rain, the Siberian thistle gets ready for rain, by keeping open. If this thistle does not close at night, you may look out for rain next day.

You see the marigold, which had origin in a hot land, stays folded, to keep the rain out of its petals. But the thistle, which had origin in a cold, stormy land, keeps wide open to get a good washing.

Did you ever see near the way-side the pretty little morning-glory or bind-weed, with its pink and white blossoms? Even if it is wide open, in the early day, it twists its striped cup close together, and droops its head, if a rain cloud drifts across the sky. It seems to want to shield its stamens and pistil from the wet.

There is a little single marigold, which shuts up in a hurry if the sky becomes clouded. It is called the “rainy-marigold.”

Most plants which we call “weather prophets” shut up for rain. But some plants open for rain. The cause of the opening and closing is probably the difference in light. Most likely, these plants shut their flowers because there is too little light, not because there is too much moisture.

But you know there are some plants which shrink from a strong light, and love the shade. You will find that most shade-loving plants, as the verbenas, do not close for rain.

Lilies, tulips, and other flowers that love the sun, shut for rain. The tulip and crocus families are among our best weather prophets. Just as the gay tulip shuts at evening, when the dew begins to fall, so it shuts for a shower.

Tulips are careful not to open their cups very wide in the morning, if it is likely to rain. The roses make no change; they seem not to fear wet.

On the whole, you may be pretty sure, if you go into your garden, and find many flowers, as tulips, marigolds, morning-glories, and celandine, shut, it will be a stormy day, unfit for picnics or long walks.

Just as some blossoms are weather prophets, so are some seeds. But in the case of the seeds it is the moisture, not the light, which affects them.

Among these seeds, that of the wild-oat is chief. When the air is moist, the long bristles, called awns, on the seed, squirm and twist. In old times, before people knew why this was, they said that this seed was a witch!