Just think of what is being done inside that quiet-looking tree! Think of the millions of cells that go to make it up, each cell having its own work to do! Think of the immense amount of business being carried on within the trunk, inside the branches, and especially in each green leaf! And when you have the chance, notice how hard each leaf tries to get just as much sun and air as it possibly can. In the first place, the thin, flat leaf blades are so spread out that every part is exposed to the light and air. Then notice how the leaves are placed in reference to one another. Almost every single one is fastened to the tree so as to get its fair share of sunshine. When you think of the many thousands of leaves borne by one tree, it astonishes you to see how seldom one leaf gets in another’s light. And the shapes of leaves are always suited to their arrangement on the tree. If you should take the leaves of a chestnut tree and replace them by the leaves of a maple, you would find the maple leaves all getting in each other’s way, or else you would see that they were taking up a great deal more room than necessary. But when a leaf is studied on its own tree, one sees that its shape is the very best that could be imagined for its position. And in the smaller plants we notice this same thing. And when you remember that Leaf Green cannot feed the plant unless Sunbeam comes to her assistance, you realize how necessary it is that each leaf be within the reach of Sunbeam’s visits. LEAVES AND ROOTS You will be surprised to learn that the way in which a plant’s leaves grow tells us something of the way in which its roots grow. Many of you have been overtaken far from home in a rainstorm, and have sought shelter under a spreading tree. The ground directly beneath the tree has kept almost dry even after some hours of rain, but the earth just under the tips of the spreading branches got very wet: for the great tree acted like a large umbrella; and when the raindrops fell upon the smooth leaves, which sloped outward and downward, they rolled from leaf to leaf till they reached the very lowest, outermost leaves of all. From these they fell to the ground, just as the drops that gather upon your umbrella run outward and downward to the umbrella’s edge, and then off upon the ground. So you can see that the circle of earth which marks the spread of the branches above must be specially wet, as it received a great part of the rain which fell upon the whole tree. And whenever you see a tree which sheds the rain water in such a circle, you can be pretty sure that, if you should dig into the earth a ditch which followed this circle, you would soon reach the tips of the new root branches of the tree.