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