But while the blossom dies, the seed bag grows larger and larger. As the seeds ripen, the bag, or case, that holds them becomes brittle. It will break easily. Often this pod, or seed bag, bursts open when the seeds are ripe. Then the seeds fly all around. They fall upon the ground. There with the wind and rain and the slight change of the top soil, they slowly sink into the dirt. They keep moist and warm until spring. Then they sprout out as you see the beans do. Some seeds will die if left to lie all winter in the ground. We say such seeds are not hardy. They are seeds that are not native to the place where they grow. Seeds are hardy in their native places. Now you have seen how the seed germ grows to be a ripe seed. You have seen how the ripe seed sprouts into a plant. You know that plants grow. They increase in size. They put out more leaves. They have flowers and seeds. How is this done? It cannot all be explained, but a little of it can be. Look at yourself. You grow. Suppose you did not eat? Would you grow? If you stop eating you will shrink up, and be thin, and even die. Have you never heard people say that if children do not have enough to eat, they will be small and not grow well? You grow by eating. So does the plant. But mind you, when we speak of the plant as eating, we mean really _drinking_. The food the plant takes from the earth must come to it in a liquid form. You know of some insects which take their food by sucking the juice out of things.[6] So the plants get their mineral food, held in water. They suck the water out of the ground, by the wee mouths at the tips of the root fibres. You know, when it is very dry the plants droop. People say “it is so dry that the crops will not grow.” Even the leaves of the trees die and fall off in a very dry time. They die for lack of food-drink. You have a stomach where the food that you get is so changed that it will make for you good blood. The blood feeds and builds up every part of your body. The plant has no stomach, but its leaves serve it for the same purpose. In the leaves the plant food is turned into stuff like the plant. But how does the food pass into the leaves? See the tall tree! How does the plant food go from the roots to the top-most leaves? It runs up little pipes or cells. Plant stems are made of bundles of these tiny pipes. Do you now fancy long slim pipes, as long as the stem or trunk of a tree? Dear me, no! These tubes are very short. But the bundles of them are laid along, all up the stem. They are laid end to end. Or you may call it one long tube, with little walls, or partitions across. How does the sap pass through these walls? It would be very hard to tell. What we know is, that it does go through very quickly. Take a flower with a clear green stem. Put it into a glass of water in which is some red or blue color. You can watch the rise of the colored water by the change in the color of the stem.