Sweet Peas and Butterflies

The
“LOOK ABOUT YOU”
Nature Study Books

BY
THOMAS W. HOARE
TEACHER OF NATURE STUDY
to the Falkirk School Board and Stirlingshire County Council

BOOK IV.

LONDON: T. C. & E. C. JACK, Ltd.
35 PATERNOSTER ROW, E.C.
AND EDINBURGH

PRINTED IN GREAT BRITAIN BY
THOMAS NELSON AND SONS, LTD.

PREFACE.

This little book should be used as a simple guide to the practical study of Nature rather than as a mere reader.

Every lesson herein set down has, during the author’s many years’ experience in teaching Nature Study, been taught by observation and practice again and again; and each time with satisfactory result. The materials required for most of the lessons—whether they be obtained from the naturalist-dealer or from the nearest hedge, ditch, or pond—are within everybody’s reach.

There is nothing that appeals to the heart of the ordinary child like living things, be they animal or vegetable, and there is no branch of education at the present day that bears, in the young mind, such excellent fruit as the study of the simple, living things around us.

Your child is nothing if not curious. He wants to understand everything that lives and moves and has its being in his bright little world.

Nature Study involves so many ingenious little deductions, that the reasoning powers are almost constantly employed, and intelligence grows proportionately. The child’s powers of observation are stimulated, and his memory is cultivated in the way most pleasing to his inquiring nature. By dissecting seeds, bulbs, buds, and flowers, his hand is trained, and methods expeditious and exact are inculcated. By drawing his specimens, no matter how roughly or rapidly, his eye is trained more thoroughly than any amount of enforced copying of stiff, uninteresting models of prisms, cones, etc., ever could train it.

The love of flowers and animals is one of the most commendable traits in the disposition of the wondering child, and ought to be encouraged above all others.

It is the author’s fondest and most sanguine hope that the working out of the exercises, of which this booklet is mainly composed, may prove much more of a joy than a task, and that the practical knowledge gained thereby may tempt his little readers to study further the great book of Nature, whose broad pages are ever open to us, and whose silent answers to our manifold questions are never very difficult to read.

T. W. H.

CONTENTS

LESSON PAGE I. [Structure of Stems] 7 II. [Bulbs and Corms] 12 III. [What Goes on Inside a Plant] 17 IV. [Snowdrop, Crocus, and Tulip] 23 V. [Vegetable Fingers] 29 VI. [The Great Water Beetle] 35 VII. [Daisies] 40 VIII. [Chaffinch and Song-Thrush] 46 IX. [Plants that Arm Themselves] 52 X. [The Horse Pond Again] 58 XI. [Wasps] 63 XII. [Dandelions] 69 XIII. [The Life of a Trout] 75 XIV. [Silkworms] 81 [Appendix] 88

“LOOK ABOUT YOU.”
BOOK IV.

I.—STRUCTURE OF STEMS.

“We are going to have a peep into the inside of these twigs,” said Uncle George, as he laid some willow and horse-chestnut twigs on the table.

“First,” he said, “let us examine the outside of them.” He handed a small willow branch to Tom and a horse-chestnut branch to Frank.

“Now, Frank, tell me all you see.”

“I see the rings of scars which mark each year’s growth,” said Frank. “This year’s growth is at the top, above the first ring of scars. Below this is last year’s growth. Then comes another ring of marks, and below this again is the growth of two years ago.”[1]

“That is to say,” said his uncle, “the upper part of your twig is about one year old, the middle part is two years old, and the lower part is three years old. Go on, Frank.”

“The upper part is light brown, while the middle and lower parts are dark brown.”

“Take your lens, Frank, and look at that brown covering carefully.”

“Oh, it is studded all over with little oval marks like pits,” said Frank.

“Now, what about the buds?”

“The buds,” said Frank, putting down his lens, “are in pairs; and the stem is swollen where each pair of buds comes off.”

“Very good,” said Uncle George. “That is exactly what I wanted you to notice. The swollen parts of a stem are called its nodes. In every stem, buds and leaves occur at the nodes. Nodes are very well seen in grass and corn stems.”

“Then at the top of the twig there is a very large bud and a pair of small buds, one on each side of it,” said Frank.

“You have described it very well,” said his uncle. “Now, Tom, what about the willow twig?”

“I see some very tiny marks on it,” said Tom. “There are no rings marking the year’s growth; and the buds are not arranged in pairs.”

Horse-Chestnut Twig, showing Three Years’ Growth.

“That is quite right, Tom. Willow grows very quickly. Your twig is all one season’s growth. It is smooth and green—not brown like the horse-chestnut twig. The buds are arranged alternately. That is to say, there is only one bud at each node.”

“Now, let us see what the horse-chestnut twig is made of.”

Uncle George next cut two pieces off the top part of the horse-chestnut twig and handed one to each of the boys.

“Now, take your knives,” he said, “and carefully peel off a very small piece of the brown covering. You will have to be very careful, as it is very thin and rather difficult to remove. Ah, Frank, you have done that very nicely. Now, hold it up to the light and tell us what you think it is for.”

“It is the skin or covering of the twig,” said Frank.

“It is; and if you look with your lens you will see that the tiny markings on it are holes. It is really a thin layer of bark or cork. Perhaps you can tell me why the twig is covered with a thin layer of cork?”

“To keep water from getting in,” said Frank.

“Rather to keep water from getting out,” said Uncle George. “You must remember that water is continually passing up stems from the roots. Water cannot pass through cork. If we were to remove the cork layer from the outside of a growing twig, that twig would shrivel up and die. There is also a layer of cork protecting the willow twig, but it is so very thin that we can see through it. Remove as much of the cork layer as you can, and tell me what is underneath.”

“There is a layer of green stuff beneath,” said Frank.

“Just so,” said Uncle George. “Now, if you remember, I once told you that plants took most of their food from the air by means of the green stuff in their leaves. This green layer in the twig does the same thing; but how can the air get in if it is covered up by a layer of cork?”

“Oh, I see now,” said Tom, “what the tiny holes or pits are for—to let air in to the green layer underneath.”

Diagram Sections of (A and B) a One-Year Old and (C and D) Two-Year Old Stem.

1. Bark. 2. Green Layer. 3. Bast. 4. Slippery Layer. 5. Wood. 6. Pith.

“That is what they are for, Tom,” said Uncle George. “Scrape away this green layer. It is greenest on the outside and is rather thick. There are really two or three layers there, but they cannot be separated with a pen-knife. What do you come to next?”

“A white, woody layer with a very slippery surface,” said Frank.

“That slippery surface is itself a layer, and a very important one,” said his uncle. “The wood, you can see, is a very thick layer. In the centre you have a mass of dry, spongy stuff. This is called the pith.”

Uncle George then cut the twig straight across, and the boys saw that each layer formed a ring. In the middle there was a round mass of pith. Around this was a thick ring of wood with the thin slippery layer outside. Outside this was a fairly thick ring, the outer half of which was green in colour. And outside the whole lot was the ring of the thin bark or cork which the boys had first examined.

“We have seen,” said Uncle George, “how a one-year-old stem is built. Let us now make a clean cut through the two-year-old part of the twig, and another through the three-year-old part.

“You see there are two rings of wood in the two-year-old part and three rings of wood in the three-year-old part. What does this show us?”

“That a ring of wood is added every year,” said Frank.

“And so, three years ago, this thick branch was a tiny bud,” said Uncle George, pointing to the lower part of the twig.

Exercises on Lesson I.

1. An apple will keep sound for months if the skin is unbroken. If we remove a small piece of the skin, the apple soon shrivels up. How is this? 2. Can you explain why we ought not to eat the outer skins of the plum, grape, tomato, pear, etc.? 3. Cut a stout twig of any tree straight through. Make a rough sketch showing the different layers, and tell how old the twig is. 4. Get stout twigs of different trees, such as ash, elm, holly, sycamore. Take about an inch length of each. Split these down the centre, and see if you can make out the different layers on each side of the pith. Make an enlarged drawing of one of these.

II.—BULBS AND CORMS.

“These,” said Uncle George, “are what we grow our snowdrops and crocuses from.”

As he spoke he handed each of the boys a few hard, round objects. Some of these were small, white, and almost pear-shaped. The others were larger, rounder, and brown in colour.

“The small white ones are snowdrop bulbs,” he continued. “The others are crocus corms. There is a great difference between a bulb and a corm, as we shall see when we examine and compare them.”

“The corm is covered with brown, papery skins, and has white buds on the top of it,” said Frank.

“These brown skins are leaves,” remarked Uncle George.

“Leaves?” said Tom. “I thought all leaves were green.”

“Oh no, Tom, there are other leaves besides green leaves, called scale-leaves. Green leaves, as you know, give off the moisture which the roots take up from the soil. They also take in plant-food from the air. Scale-leaves protect buds, flowers, and tender stems from cold and from insects. These thin brown leaves of the crocus corm are scale-leaves formed underground. Please remove the brown scale-leaves from one of the corms, Frank.”

1. Snowdrop. 2. Tulip. 3. Narcissus. 4. Crocus.

When Frank had done so, it was seen that these leaves were attached in layers all round the corm. The corm was now a white, rounded lump. The removal of the scale-leaves had left thin rings of leaf-marks; and on these leaf-marks, here and there a tiny bud was seen.

“Now,” said Uncle George, “we can see that a corm is a stout, swollen, underground stem. If you could imagine a horse-chestnut stem to be squeezed up into a lump, you would have something like a corm. These rings of leaf-marks are the nodes, where leaves and buds are found on all stems. The large buds on the top of the corm correspond to the large buds at the end of your horse-chestnut stem. Now, let us take off one of these large top buds. Notice that it is covered with many tough, protective scale-leaves.”

Crocus Bud Dissected.

1. Scales. 2, 3, 4. Parts of Flower. 5. Leaves. 6. Spathe. 7. Ovary. 8. Young Corm. A. Old Corm.

Removing these scales, Uncle George came to a round object in the centre.

“This,” he said, “is a long sack or bag. It contains the flower of the crocus.”

Taking a needle, he carefully opened this up.

“Now, boys,” he said, “take your magnifiers and look carefully.”

Frank and Tom looked, and saw a curious little flower, surrounded by four or five yellow needle-shaped things which, their uncle told them, were the young green leaves of the crocus.

“Let us now,” he said, “examine the snowdrop bulb.

“Here we have thick, fleshy scale-leaves. If we remove them one by one, we find that they are all attached to a flat, button-shaped stem. Between the thick scale-leaves we see, here and there, a small side bud, and on the top the baby snowdrop flower snugly wrapped up in their sack. This protective sack is called a spathe.”

Uncle George then took from his pocket a very large bulb.

“This,” he said, “is the bulb of the narcissus or ‘white lily.’ It is almost exactly like the snowdrop bulb, but it is larger, so that we can see things much more distinctly.”

He then split the large bulb down the centre with his knife. With a pin he pointed out the baby flower wrapped up in its spathe. All the parts of the flower were seen, even the little seed-vessel containing the tiny eggs, which become seeds after the flower has grown up.

“If you remember,” said Uncle George, “in our lesson on seeds we learned that a seed contained a baby plant and a large supply of plant-food. I am now going to show you that both the corm and the bulb contain a large food supply. We have seen that the protective bud-scales in the corm are tough and thin, while the stem is swollen and hard. In the bulb, on the other hand, the bud-scales are thick and fleshy, while the stem is flat and very small. If we place some of our crocus corms or snowdrop bulbs in pure water, they will grow and flower just as well as if we had planted them in the garden. What does this show us?”

“That, like the seeds which we grew in water, bulbs and corms contain a store of food,” said Frank.

A. Narcissus Bulb split open. s., stem; b., side buds; s.l., scale-leaves; f.l., leaves. B. Snowdrop Bulb. C. Flower of same Dissected out.

“That is correct, Frank. Let us put a corm and a bulb in water. Let us also plant one of each in a pot of soil. We will watch them growing and compare them from week to week.

“Now I am going to show you a simple experiment. You know that the food we eat is drawn largely from plants. This food which we take from the plant world is chiefly what the chemist calls starch. We have it in bread, potatoes, rice, cornflour, and in nearly all the vegetables we eat.

“I have here in this bottle a substance, called iodine, dissolved in water. Anything containing starch turns blue when touched with iodine. Now observe what happens here.”

Uncle George poured some of the iodine into a saucer. He then dipped into the iodine a piece of crocus corm, a thick scale of the snowdrop bulb, soaked seeds of maize and wheat, a slice of raw potato, and a piece of bread. Each at once turned dark blue on being dipped into the liquid.

“Now, boys,” he said, “what do you learn from this?”

“The food store in bulbs and corms is the same as that in seeds,” said Tom.

“The food supply of the bulb is contained in the thick, fleshy scale-leaves, while in the corm it is in the stem,” said Frank.

“Very good,” said Uncle George. “It also shows us, I think, that we ourselves owe a great deal to the plant world.”

Exercises on Lesson II.

1. Split an onion (or tulip bulb) down the centre, and compare it with the snowdrop bulb. Draw it, giving special attention to the middle part. 2. Take a potato and a crocus corm. Observe them both carefully, and find out (1) how they resemble each other, and (2) how they differ. 3. Explain how it is that a hyacinth grows so well in water. 4. Take any underground stem (e.g., iris or Solomon’s seal) and compare it with a crocus corm. Notice the marks of underground scale-leaves on the former.

III.—WHAT GOES ON INSIDE A PLANT.

“We have seen how an ordinary twig is built up,” said Uncle George. “Let us now try to find out what goes on inside the twig; and in order to do this we shall have to perform one or two simple experiments.”

Uncle George took two wide-mouthed glass jars. They were both perfectly dry, and each could be closed with a large, tight-fitting cork. He placed some fresh green leaves inside one of the jars. The other remained empty. Then both jars were tightly corked up, and both corks covered outside with wax.

First Experiment.

“That is experiment number one,” he said, as he placed both jars in the window.

He next took a small plant which was growing in a pot. He wrapped the pot up in thick, dry paper, so that the paper covered up everything but the plant. The edges of the paper were tied tightly round the lower part of the stem of the plant with a string. The plant was put in the window, and over it Uncle George placed a glass bell-jar.

Second Experiment.

“The third experiment is much simpler,” he said. “You see I just put one of the willow twigs into a glass half filled with water, and into the water I pour some red ink. Frank, place a white pansy in the coloured water beside the willow twig.”

Uncle George’s fourth experiment was as follows:—

He placed four willow twigs in a glass of water. But from two of these twigs he first removed a broad ring of the bark and outer layers, leaving about an inch of the wood bare near the lower end of the twig.

“Now,” said he, “we will come back in about an hour, and I think we shall find that some change has taken place in each of our first three jars.

“The fourth glass one will have to be left for several weeks; and we must take care to keep water always in the glass containing these four twigs.”

About an hour afterwards, Uncle George and the boys came to look at the experiments.

“Let us examine experiment one first,” said Uncle George.

“The empty jar is just the same as when we put it there,” said Tom. “The jar containing the leaves is all dimmed, and there are tiny drops of water on the inside of it.”

“Where did that water come from, Tom?”

“It must have come out of the leaves.”

“Exactly so! Now look at the second experiment, and you will see that the bell-jar which covered both plant and pot is also dimmed with moisture. Pot and soil were securely covered up, so that this moisture on the glass must have come from the leaves of the plant. Where do you think this water really comes from?”

“From the soil in the pot,” said Frank. “If we did not water those plants which we keep in pots, they would die.”

“Then we have learnt that water travels up the stems of plants,” said Uncle George, “also that it is drawn from the soil and is given off by the leaves. The third experiment, where we placed a twig in coloured water, will, I think, show us which part of the stem the water travels up.”

Uncle George peeled the bark off the lower end of the willow twig which was placed in the mixture of red ink and water. He removed all the layers until he came to the wood. The wood was stained red. He cut slice after slice off the twig, and it was found that the coloured water had gone quite an inch up through the wood. None of the other layers of the twig were stained red.

“It travels up through the wood-layer,” said Frank. “And look at the pansy flower. It was white when we put it into the glass, now it is all streaked with red.”

“The flower itself,” said Uncle George, “is not near the coloured water.”

“The water must have travelled up the long stalk to the flower,” said Frank.

The Fourth Experiment.

The fourth experiment was left in the window, and two or three weeks passed before any change was noticed in any of the four twigs which had been placed in the water. Then roots began to grow. In the two whole twigs these roots grew out at the bottom end. But in those twigs from which the belt of outer layers had been removed, it was quite different. Here the roots grew out—not at the bottom, but just where the ring of bare wood began and at the top of it.

Frank and Tom were quite puzzled. They could not understand why the roots should come at the bottom in two of the twigs and not in the other two.

“First of all, then,” said Uncle George, “these new roots were made from materials which came from inside the plant. These building materials are carried through the plant dissolved in water—just as you dissolve sugar in your tea. Water containing these dissolved stuffs in a plant is called sap.

“We have seen, by our first three experiments, that water travels up the wood part of the stem. This experiment shows us that sap travels down the stem in the layers outside the wood. For, when I removed the outer layers and left a bare ring of wood, the flow of the sap was stopped and the new roots formed there.”

“And where does this sap come from first of all?” Tom asked.

“It is really formed in the leaf first of all. I think I told you that plants take most of their food from the air by means of their green leaves. In the great quantities of water which pass up the wood and into the air from the leaves there is always a very little mineral matter dissolved. This small quantity of mineral matter comes from the soil. This, along with water and the large quantity of matter taken from the air, are changed, inside the leaf, into a fluid which we call sap.

“Our four experiments show us that water travels up through the wood-layer from soil to leaf; and also that sap travels down through one of the outside layers of the stem.”

Questions on Lesson III.

1. How does water travel in a plant? How can you prove this? 2. If we enclose a leafy plant in a glass vessel, we see that water is given off by the leaves. How is it that we do not see this water when the plant is grown in the open air? 3. What is “sap”? Where is it first formed? How does it travel in the twig or stem? 4. If we keep ferns growing under a glass bell—or in a glass case—we never have to water them. Can you explain this?

IV.—SNOWDROP, CROCUS, AND TULIP.

The boys watched the growth of the crocuses in water and in soil from day to day, and made sketches of them once a week. Fed by the food contained in the corm, the top buds of the crocus grew longer. Then the scales moved apart and the yellow flower was seen. Round about it were four or five narrow green leaves, each having a pretty white stripe down the middle. Both leaves and flower were encircled at the base by long white sheaths.

The crocus grown in the pot did not seem to thrive much better than the one in the water. Both flowers remained closed for a long time after they were full grown.

At last, on one fine sunny day, they opened out wide at the top, and the boys could see right down into them. In the evening they closed up again. Next day was a dull day, and the crocus flowers remained closed.

The snowdrops were also watched and sketched. Their growth was somewhat different. From the centre of the little bulb two green leaves first appeared. These leaves were much broader and thicker than those of the crocus. From between these leaves a little white, flat object grew up. This the boys at once recognised as the spathe or bag containing the flower. Then more green leaves came up. The flower-stalk grew longer. The spathe split open, and the flower-bud appeared.

This bud grew until it became a beautiful white bell hanging downwards.

Crocus Flowers.

In a large pot Uncle George had planted a few tulip bulbs. They were not completely covered with soil, so that their growth could be watched. Their growth was similar to that of the snowdrop. The leaves came first. They were rolled firmly round each other. As each large, broad, green leaf unrolled, another rolled-up leaf was seen under it. These leaves were rolled round a thick stalk, to which they were attached. When the last leaf unrolled, a single flower was seen at the top of the stalk. This flower remained closed up like the crocus. When at length, however, the warm sun shone in the window, the tulip flowers opened out very wide indeed; in fact, they became almost saucer-shaped.

Then Uncle George dug the snowdrop and crocus out of their pots. He washed the roots and asked the boys to compare them with those grown in water.

“The plants grown in soil seem stronger in flower and leaves,” said Frank. “But the greatest difference is in the corm and bulb.”

“That is right, Frank,” said Uncle George. “Look at the crocus corms. They have both shrunk a great deal, because they have been used up to form what has grown out of them. But the one grown in soil has formed a new corm, which will produce new flowers next year. This new corm has grown upon the top of the old one. The crocus grown in water has also produced a new corm, but it is too small to produce a flower next year.

“Then, again, take the snowdrop. The one grown in the soil has produced two or three new bulbs, while that grown in water has not. These new bulbs were the side buds we noticed between the scales when we opened out our snowdrop bulb. In both snowdrops the old bulb has been completely used up to form green leaves and flower.

“But the bulb grown in soil has not only produced flowers and green leaves. It has gathered up enough material from soil and air to form new bulbs for next year.”

1. Snowdrop Flower—A, the spathe. 2. Crocus Plant. 3. Old and Young Corms of Crocus. 4. Young Snowdrop Flower enclosed in its spathe. 5. Crocus Flower. 6. Tulip Flower dissected.

Uncle George then divided the crocus flower with his knife from top to bottom.

“At the very bottom of the flower,” he said, “you see the ovary, or seed-vessel, containing the tiny seeds. From the seed-vessel a long thin rod or tube stretches to the very mouth of the flower. You can also see the remains of the spathe which once enclosed the whole flower.”

“And what are those three things covered with orange-coloured dust?” asked Tom.

“These,” said his uncle, “are the stamens or pollen-boxes; and the orange-coloured powder is the pollen. This pollen is carried about from flower to flower by the bees. Pollen is necessary for the production of seeds.

“Do you know why the seed-vessel of the crocus is so far down under the ground?

“It is because the crocus flowers in winter-time, and the frost might kill the young seeds. Underground they are safe from frost. The snowdrop is a hardy flower, and, besides, the walls of its seed-vessel are very thick.

“The tulip, if grown outside, flowers much later than the other two plants.

“Notice the difference between the flower of the tulip and those of either crocus or snowdrop. Its petals are all separate, while those of the others are joined to form a bell or tube. The seed-vessel of the tulip, also, stands right up in the centre of the flower, while that of the snowdrop (and crocus) is placed underneath the flower altogether.”

“How is it, Uncle George, that the flowers of both tulip and crocus open out wide when the sun shines and close when the sun goes down?” asked Frank.

“Plants can feel to a certain extent,” said Uncle George. “That is to say, they are affected by heat and cold, by light and shade. A great many flowers close up at night—the daisy, for instance; and have you never noticed how clover leaves fold up long before night comes?”

“Yes, but why should the crocus and tulip open and close? The snowdrop never closes up.”

“They do so to protect their pollen,” his uncle answered. “Rain or dew would ruin pollen. Those flowers, like the crocus and tulip, which open out to the sky must close up, or the precious pollen would be destroyed. Flowers like the snowdrop and bluebell, which hang downwards, have no need to close up, for their pollen is under a roof of joined petals.”

Exercises on Lesson IV.

1. Place an onion or daffodil bulb in the mouth of a bottle containing water. Keep it in the dark for about ten days. Then place it in the window. Make sketches every week. 2. Make a list of all the plants you know which close their flowers, or fold up their leaves, at night. 3. Cut open a flower of the daffodil (or narcissus), also one of the wallflower. Draw both, naming their parts. What points of difference do you notice in the two flowers? 4. Examine the following flowers, and see if you can find where the young seeds are:—Hyacinth, primrose, violet (or pansy), chickweed, Christmas rose, shepherd’s purse.

V.—VEGETABLE FINGERS.

When the sweet-peas in the garden were nearly full grown, Uncle George sowed some sweet-peas in a pot. In a fortnight those sown in the pot were about four inches in height, and those in the garden were in flower.

“Let us go into the garden, boys,” he said, “and see if we can learn something from the sweet-pea.”

In the garden the sweet-peas were really lovely. They looked, as Frank said, like so many beautiful butterflies on the wing; and they filled the air with delicious perfume.

“I think,” said Frank, “that our row of sweet-peas is by far the best thing in the garden.”

“That is quite true, Frank,” said his uncle, “but it is not so much the flowers we are going to study at present. The sweet-pea is certainly one of our finest flowering plants. It is also one of the most interesting. Can you tell me why we put stakes up for our sweet-pea plants to cling to?”

“Because they have long, slender stems—too slender and weak to grow up by themselves,” said Frank.

“Quite right, Frank. If the sweet-pea were a wild plant, where would it grow?”

“In the hedges,” said Tom.

“Right again,” said Uncle George. “If we grow the sweet-pea in the garden, we must imitate its surroundings in the wild state—we must give it a hedge of some kind to cling to, otherwise it would trail along the ground.”

“Then it would get choked among the other plants,” said Frank.

Rose Leaf. Vetch Leaf. Ash Leaf.

“What do you mean by ‘choked,’ Frank?”

“Well, it would die for want of air”——

“And light,” his uncle added. “No green plant can live without air and sunlight; and, in order to get these, our weak-stemmed sweet-pea has to climb. It clings to its stronger brethren just as the wild peas do in the hedgerow. Now notice how it climbs. The end part of each leaf consists of little gripping organs called tendrils. These twine tightly round the smallest twigs near them.

1. Ox Eye. 2. Daisy. 3. Corn Marigold.

“Here is a rose leaf. It is composed of several leaflets, and at its base there are two small, brownish-green things called stipules. If we compare this leaf with the leaf of the sweet-pea, we find that in some points they are similar, but in others very different.

Sweet-Pea. Edible Pea.

“The rose leaf is called a compound leaf, because it is made up of many small leaflets. The sweet-pea leaf is also a compound leaf, but it has only two leaflets, and these are of enormous size. The rose leaf has two small stipules. The stipules of the sweet-pea leaf are large and green.

“If I place the rose leaf beside a sweet-pea leaf, you will notice that the latter has no upper leaflets.”

“It has tendrils ‘instead,’” said Frank.

“Exactly!” said Uncle George. “These tendrils correspond to leaflets. Now, if the plant has been forced to turn all its leaflets, except two, into gripping organs, how does it manage to make up for this loss of green leaves?

Young Edible Pea.

“We have already learned that plants take in food from the air by means of the green substance in their leaves. The more of this green substance a plant possesses, the more food it can take in from the air. If it sacrifices leaves in order to climb up to the light and air, its amount of the green material must be lessened. But the sweet-pea makes up for this loss of leaves. Can you see how it does so?”

“The stipules are very large,” said Frank.

“And the lower part of the leaf-stalk is very flat, broad, and green,” added Tom.

“Very good,” said Uncle George, “but look at the long, slender stem. It has flat, green, ribbon-like outgrowths on each side throughout its whole length. So, you see, what the plant loses in leaves, it makes up in another way.

“Let us now look at the ordinary pea plant. Its leaf has four pairs of leaflets and three pairs of tendrils besides the terminal tendril—seven tendrils altogether. The stipules here are also very large—much larger than those of the sweet-pea. But the stem is round and smooth. There are no green outgrowths. Here is a wild pea, which I found to-day, which has no leaves at all. All its leaflets have been turned into tendrils or gripping organs. But look at the enormous stipules it has! They are much bigger than ordinary pea leaves.

A Wild Pea with no Leaves. Young Sweet-Peas have no Tendrils.

“Let us now look at the tendrils of the sweet-pea, and see how they grip their supports. Notice that they begin to twist long before they reach the supporting twig. Then, when they have reached it, they twist round it in the opposite way—just like a piece of string, if you twist it at one end, it untwists at the other.”

“Can you see any reason for this coiling before it reaches the twig?” As he spoke, Uncle George pulled a sweet-pea plant out from its supports, and the boys saw that the tendril was really a spiral spring. The plant could be pulled out a considerable length without breaking the tendril.

“You see,” Uncle George continued, “if it were not for that first coiling of the tendril—that is to say, if the tendril grew out straight and only began to twist when it reached the twig—the first breeze of wind would snap the plant from its supports and it would fall to the ground.

“Look now, at the young sweet-peas which we grew in the pot. They are without tendrils of any kind. This shows us, I think, that the sweet-pea was at one time a small plant, like its relative the clover. It grew in open places and did not have to struggle for light and air. But, by and by, when strong growing plants took up the soil, it became forced to produce climbing organs or become choked out. And, having turned its leaves into climbing or gripping organs, it made up for the loss of leaves by producing large stipules and green out-growths to stem and leaf.”

Exercises on Lesson V.

1. Draw a leaf of the wild rose and one of the sweet-pea side by side. 2. Make a list of all the climbing plants you know, and state how each climbs. 3. Look for stipules on the apple, pansy, and bean leaves—make sketches. 4. Those plants of the pea family which have many leaflets have smooth round stems. Those which have few leaflets have “winged” stems. Can you explain this?

VI.—THE GREAT WATER BEETLE.

During summer the boys paid many visits to the horse pond. Each time they went there they saw something to interest them.

Their uncle taught them to keep perfectly still while looking into the water. They soon came to know that this was the best way to study pond-life, for, whenever they moved, the creatures they were watching would dart out of sight.

One day, while they were both lying on the bank gazing into the pond, a huge black beetle came up to the surface of the water. It remained there for a few moments, with its head hanging downwards and its tail sticking right out of the water. Then it dived down out of sight. In a few minutes it came up again, and this time Frank’s net was under it before it could escape.

Just as Frank was putting it into the glass jar, Tom whispered, “Here is another one—quick, Frank!”

But Frank was too late; for before he could get the first beetle into the jar, the second one had dived to the bottom of the pond. The boys waited for a long time, hoping to see the other beetle again. At last their patience was rewarded. The beetle came up again to the surface. As soon as it did so, in went the net, and out came beetle number two.

“What big beauties,” said Frank. “I wonder what they are. Let us hurry home and show them to Uncle George.”

When they got home, their uncle placed the two beetles in a glass tank by themselves, so that they could be more easily observed.

“What do you call them, uncle?” asked Frank. “We have never seen such large, handsome beetles before.”

Dyticus Beetle, male and female.

“Have you not?” his uncle replied. “I am surprised at that, for this beetle is found in nearly all our ponds and ditches. It has a long Latin name,[2] which means Bordered Diver, but it is commonly known as the ‘great water beetle.’ There are several kinds of these diving beetles. This is the largest. Can you give me an idea of their size?”

And Uncle George handed Frank a small measuring rule which he carried in his pocket.

Frank looked at the beetles, and then moved his thumb nail along the rule.

“About an inch and a half in length,” he said.

“That is about right,” said his uncle. “Are these two beetles exactly alike?”

“They are both about the same shape and colour. One is slightly bigger than the other. They are both greenish-black above and brown below. There is a curious broad border of yellow all round the edge of their bodies,” said Tom.

“But they are not both exactly alike,” said Frank, “I notice that one is smooth on the back, while the other’s back is all grooved.”

“You are right, Frank,” said Uncle George. “The one with the grooved wing-cases is the female. The one with the smooth cases is the male.

Fore Leg of Male, showing Sucker Organ.

“Notice the long legs they have for swimming, and how they seem to oar themselves through the water. Notice also that the male has a large flat disc upon each of his fore legs. These are suckers, by which he can cling to things.”

“Why do they come up to the surface so often?” Frank asked.

“They cannot live without air. They carry a supply of air under their wing-cases. They just come up to renew it from time to time. This is done by thrusting the end of their bodies out of the water as you see.”

“One would think they ought to thrust their heads out to get air,” said Tom.

“That seems more natural to us, because we breathe with our mouths,” said Uncle George. “These animals take in air with their tails. A great many pond insects breathe in this curious way.”

“What do they feed upon?” Frank asked.

“They are fierce, greedy creatures,” his uncle replied. “They attack and kill worms, tadpoles, and even small fishes.”

Uncle George threw a small worm into the tank. One of the beetles seized it at once and began to devour it greedily. Presently the other beetle seized an end of the worm. The boys watched closely, and saw that the beetles’ jaws moved from side to side like a pair of pincers.

Next morning, when Uncle George and the boys went in to see the beetles, they found only one in the tank. The other had escaped during the night. After a careful search they found it, at the far end of the room, dead.

“Now, how do you think this beetle managed to get out of the tank and travel all that way?” Uncle George asked.

“It must have crawled up the inside of the tank, then down the outside. Then it must have fallen off the window-sill, and crawled right across the floor,” said Frank.

Uncle George shook his head.

“It might,” he said, “have managed to crawl up to the edge of the tank so long as its legs were wet. But as its long legs are made for swimming, and not for crawling with, I can hardly see how it could have crawled or walked all that distance.”

“Then how did it get there, Uncle George?”

In answer to Frank’s question, his uncle took the dead beetle, and placed it on a piece of paper on the table. He next moved aside each of the large black wing-cases with a pin.

Underneath these wing-cases the boys saw a pair of large wings neatly folded up. Uncle George removed one of the wing-cases, and unfolded one of the wings. Stretched out, it was longer than the beetle’s body, and it seemed to be made up of thin, clear skin, stretched on a framework of long, thin supports.

“Why, these beetles can fly,” said Tom.

Male and Female Beetles, showing Flying Wings.

“Of course they can,” said his uncle. “All beetles can fly. This creature has evidently been flying about the room all night. These insects are furnished with wings, so that they may be able to fly to another pool when food gets scarce, or when their pool dries up.”

Exercises on Lesson VI.

1. Would you keep water beetles, tadpoles, and stickle-backs together? Give your reasons. 2. Water beetles cannot live without air. Explain how they get it. 3. Compare the legs of a water beetle with those of any of our garden beetles. 4. Why are water beetles furnished with wings?

VII.—DAISIES.

While Uncle George and Frank and Tom were having a game of cricket, Dolly was amusing herself in another way. She had pulled a bunch of daisies and was joining them up into a daisy chain.

Common Daisy.

She finished her daisy chain just as her uncle and the boys finished their game.

“We will take some daisies home,” said Uncle George. He stooped down and dug out a whole daisy plant with his knife, while Dolly gathered a small bunch of the flowers. When they got home Uncle George placed his daisy plant in a saucer of water, and told the boys to bring out their magnifiers and sketch-books.

“First of all,” he said, “I want you to look at the daisy plant. Notice its leaves. Each leaf is broad at the end and narrow where it joins the plant. Notice also that the leaves all form a round green mat on the ground. Now, can you tell me what the leaf resembles in shape.”

1. Daisy Leaf. 2. Primrose Leaf. 3. Cowslip Leaf.

“It is like a spoon,” said Tom. “It is,” said his uncle; “and can you see any reason for it being so shaped?

“You cannot? Well, I must tell you. All plants whose leaves are all at the ground have leaves shaped something like this. The primrose and cowslip are good examples. We have seen that plants, like the pea, climb up so that their leaves and green parts may get as much light and air as possible. And if you look at any tree, such as the horse-chestnut, ash, elm, or beech, you will notice that their leaves are spread out so as to catch as much light as possible.”

Uncle George then drew a circle.

1 and 2. Diagram to show Leaf arrangement of Daisy. 3. Head of Daisy split. 4. Outer Floret. 5. Inner Floret.

“Now, boys,” he said, “I want you to try to fill that circle with leaves so shaped that they will fill it without covering one another. The best way to do so is to make them broad at the end. If you make them broad at the base and narrow at the end, they overlap and rob each other of light and air. Now you can see why the leaves of the daisy are so shaped.

“Take up a daisy and split it down the centre with your knife. You will notice that the daisy is not a flower, but a collection of tiny flowers, or florets, all packed closely together upon a pad or disc, and surrounded outside by many little green things like small leaves. These little leaf-like things are called bracts.”

London Pride, showing Leaf arrangement.

“There are two distinct kinds of florets,” said Frank, looking at the split daisy with his lens.

“Yes,” said Uncle George, “you will see them better if you remove one of each with a pin, and examine them separately.”

“The outer florets are very large and white,” said Frank.

“They are very flat, while the inner ones are yellow and round. They are very like small crocus flowers. What is that small two-headed thing that comes out in the centre of each floret?”

“That is the part which leads to the seed-vessel. Can you see the seed-vessel at the bottom of each floret?”

“Yes,” said Tom, “it is large and round. On the top of it and all round the petal part of the floret there are long silky hairs.”

“In flowers of this kind, when the seeds are ripe they are carried away by the wind,” said Uncle George. “The petal part withers, but the tuft of hairs remain. They are to the seed what sails are to a ship. They are much better seen in some other flowers related to the daisy, such as the thistle.

“Now cut open the seed-vessel and see how many seeds it contains.”

“There is only one, I think,” said Frank.

“You think correctly,” said his uncle. “Each seed-vessel holds a single seed.”

“The seed-vessel in the large white floret is small and flat,” said Tom.

“It is,” said Uncle George. “In fact, the outer florets seldom produce seeds.”

“Then what is the use of them?” Tom asked.

“I’ll show you,” said Uncle George. As he spoke he took up a fresh daisy flower.

“Look!” he said, “what a pretty flower it is, with its golden centre and its bright white edge tipped with red. It is like a beautiful star.”

Then he pulled off all the large white florets.

“Look at it now,” he said. “It is a dingy, ugly little flower. Without its white florets it would not be seen at all. Now perhaps you can tell me what the large white florets are for.”

“To help us to see them at a distance,” said Frank.

“So that bees and other flying insects may be able to see them,” said Uncle George.

“Insects visit flowers for honey, and, in doing so, carry the yellow dust, or pollen, from flower to flower. This pollen, as I told you before, has to do with the making of seeds: and stronger seeds are produced if the pollen comes from another flower.

“Now compare a white floret with a yellow one, and you will notice still another difference between them.

“Round the stigma—that is the forked tube which leads to the seed-vessel—in the yellow florets, there is a yellow ring of stamens, or pollen-boxes. It is shaped like a little barrel with its ends knocked out, and the stigma grows right up through it.

“In the white florets there are no pollen-boxes of any kind.

“Thus, we see that the inner florets are perfect florets which produce seeds.

“The outer florets have all run to petal. Their business is to show the way to the plain little florets in the middle.

“There is another thing about the daisy that I should like you to notice,” Uncle George continued. “If you go out on a dull day, or in the evening, you will find all the daisy flowers closed up. They only open out in bright sunshine, when all the insects are flying about.”

Exercises on Lesson VII.

1. Daises are called “composite” flowers. Can you tell why? Cut a large “ox-eye daisy” or corn marigold through the centre and examine the florets carefully. 2. Using a lens, draw separately, an inside and an outside floret. Make your drawings large, and name the various parts of each floret. 3. Take two ox-eye daisies. Pull off all the white florets of one of them. Then compare them. Pin both flowers up on the wall. Go back about thirty paces and note which flower is best seen. 4. The daisy leaves form a little rosette on the ground. Make a collection of wild plants which have similar leaves. Draw a single leaf of each, and compare with those of the daisy.

Nest of Chaffinch.

VIII.—CHAFFINCH AND SONG-THRUSH.

It was Frank who found the chaffinch’s nest in the wood. It was built in the fork of a small tree, about eight feet from the ground.