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. [Illustration] 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. [Illustration] 1. Ox Eye. 2. Daisy. 3. Corn Marigold.