You know how the bees and butterflies and all sorts of insects carry the pollen from flower to flower and dust the stigmas with it. You may think that when a pollen grain is safely landed on a stigma then the rest is easy enough. But if you suppose the pollen grain can pass through the style you are _very_ much mistaken. It cannot even pass through the stigma. It is true, the tissues of both style and stigma are rather loose, and that the style is sometimes hollow. But, as far as I know, the pollen _never_ passes through. Small as it is, it is too large to get through the tiny openings in the stigma, and then, you know, the stigma is sticky and holds it fast. Here is an interesting state of affairs! The ovule cell is waiting for protoplasm, and the pollen cell is anchored safe and fast at the stigma. But you may be sure there is a way out of this difficulty. [Illustration: [Pollen]] To begin, the pollen grain has two coats, a tough outer one and a delicate inner one. There are openings, or at least weak places, in the outer coat, and after the pollen has lodged on the moist stigma, the protoplasm inside swells and comes bulging through these weak places. The inner coat is forced out, as though some _extremely_ small fairy had stuck her finger through the wall from the inside and pushed out a part of the inner lining. Well, this finger-like part that comes through the wall does not break open, but begins to grow. It grows longer and longer until a tube is formed, a tube so small that only the microscope can enable us to see it. This tube pushes its way through the stigma into the style; there it continues to grow like a long root, only it is _not_ a root, and it is hollow; and the protoplasm from the inside of the pollen grain runs down this tube. [Illustration: [Pollen]] You can guess what happens next. The tube grows and grows; it finds plenty of nourishment in the tissue of the style, which is made of material suitable to feed it. Of course, it grows down the style into the ovary, because the style opens into the ovary. When it reaches the ovary it finds its way to an ovule, and goes in at a little door which the ovule keeps open for it. Now, you see, there is an open path between the pollen grain and the ovule, and the protoplasm from the pollen grain which has run down the tube enters the ovule. Here it passes out of the tube by breaking through the delicate wall, and unites with the protoplasm of the ovule. Thus the ovule is fertilized. It is nourished and strengthened, and at once begins to grow into a seed. Meantime the shell of the pollen lies on the stigma, a little dried-up, empty thing. Its work is done. Thanks to the bee or the butterfly or some other flower-loving friend, it has been taken to the right place, and all that was living in it, its protoplasm, goes on living in the little ovule.