Part 6

“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.