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

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.”

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.