Thus you see the green leaves are the stomach of the plant. In them all the food is made of use. FOOTNOTES: [7] This process is not only a cooking by heat, but the rays of light cause chemical changes which cannot be explained in a book like this. LESSON VII. SEEDS AND LEAVES. [Illustration: TREASURE-BOXES.] The seed is the egg of the plant. Just as the new chick is in the egg of the hen, or the new wasp is in the egg of the wasp, the new plant is in the seed. Let us look at a hen’s egg. It has a shell. Inside the shell is the clear white. Inside the white is the yellow ball, or yolk. The shell keeps the white and yolk safe. The white and yolk of the egg make the food by which the chick lives and grows, before it is hatched. In the yolk you may see a tiny spot, which is the germ out of which the young chick will grow. The eggs of all birds and insects vary little from this plan. The flower-seed is also an egg made on this same pattern. The skin you saw on the bean serves for the shell. There is an inner skin often, like the silken skin inside the egg-shell. The food stored up in the seed-leaves serves as the yolk and white of the egg. The tiny germ between answers to the spot in the yolk, which is the chick germ. The seeds of flowers differ more than the eggs of birds and insects. For some seeds have no coats at all. Some have only one. But in this lesson we speak of seeds as they commonly are. We tell you of seeds as you are likely to see them. The rarer things you must learn in larger books. Let us look at seeds a little. Think how they differ in size. A great cocoanut is a very huge seed. If you ask your mother to show you her garden-seeds, you will find some as small as the finest grains of dust. Seeds vary in color. Did any one ever give you a little round, bright India bean? It was red as a drop of blood. It had a jet black mark on one side. If you look in the grocer’s window, you will see yellow peas and green ones. You will see beans,--black, white, brown, yellow, purple, and spotted. Some of the garden-seeds are purple. Some look like the filings of steel, or silver, or gold. Seeds vary in shape. You know how acorns and chestnuts look; they are seeds. Cherry-pits--stones, you call them, they are so hard--are round. A melon-seed is flat. Some seeds are three-cornered. Some have lines and dots as if they were carved. Some seeds have little hooks on them to hold them to the ground so that they may not blow away. Other seeds use these hooks to catch upon things, that will carry them from place to place. Did you ever see a thistle or dandelion seed go sailing through the air? It looks like a little silver ship, or balloon. It has a fine little feather on it to keep it up. The reason why thistles and dandelions grow far and wide is, that their seeds are carried about on the breeze.