Questions.—What is said of one of the uses of leaves? What of the variety in their shapes? Mention some of these shapes. In what other things do leaves vary besides shape? What is said of the arrangement of leaves on their stems? What is said of their different sizes? What is said about observing the shapes of leaves?
CHAPTER XVIII.
MORE ABOUT LEAVES.
Beauty of common leaves.
Leaves are such common things that we do not think how beautiful they are. But take any common leaf into your hand and look at it. Take the leaf of the strawberry. See how prettily it is notched. Hold it up to the light and see the lines that run from the middle line to the edge. Then see the fine net-work between these lines. How delicate and beautiful! The leaf of the raspberry is even more beautiful than the strawberry leaf, if you pick it from a new shoot. See the fine points on its edge, and see how delicate are its lines and net-work as you hold it up to the light.
Ribs in leaves.
Observe the back of a leaf, and you will see ribs that spread out from the main rib in the middle to the edges. These are the frame of the leaf, just as timbers are the frame of a house. They are to the leaf what whalebones are to an umbrella. They give strength to it. Without them it would droop like a wilted leaf. It would not stand out straight and firm. The wind would blow it every way, like a rag tied to a stick.
You see these ribs very large in broad spreading leaves. They are large in grape-leaves, and in the leaves of the rhubarb-plant, or pie-plant, as it is often called.
In leaves that are very stiff and firm these ribs are so small, that at first you would say there were none. This is the case with the leaf of the pear and the orange. There is one strong rib running through in the middle of the leaf. But there are no strong ribs branching out from this. The leaf is so firm that it does not need them.
The upper and under side of leaves.