And to this day that is all a pistil is,—a leaf, or a whorl or circle of leaves, rolled together, with seeds growing along the inner part. Of course, in time, these pistil leaves changed very much, and to-day we find all sorts of pistils, and by just looking at them, we would never suspect they were leaves or ever had been. And they are not leaves any more, and they themselves never have been leaves; but long ago the pistils of their ancestors were leaves or parts of leaves, and they have inherited and improved upon these pistil leaves, as a boy improves upon a willow twig and makes it into a beautiful carved whistle that does not look at all like a willow twig, and yet that is just what it is at heart. So you see, one of the most important parts of the flower is, after all, “nothing but leaves.” After seeing how the pistil, with its seed-children, is modified leaves, you will not be surprised to learn that stamens, too, are merely modified leaves. Anyway, whether you are surprised or not, that is just what they are. Tender little leaves folded a part of themselves together into little rooms or cells, and on the inside of these cells the pollen grains grew. [Illustration: [Cactus]] Now the plant was all fitted out. It had flowers, not very beautiful ones, to be sure, as they had nothing but pistils and stamens. Still they were flowers, and flowers are flowers whether they are bright or not. Pistils and stamens were enough at first. But times change. Each plant tried every possible means to make strong seeds, so it could live in the crowded world. It did not wish to be crowded out, you see. So when it discovered the value of cross-fertilization, it began, so to speak, to invent ways to bring this about. The insects with wings came to it and brought it pollen, so it learned to coax the insects to come oftener. It made quantities of pollen, so the insect could eat what it would and still leave enough for the plant. It, no doubt, had several rows of stamens, as a wild rose or a cactus flower has to-day. But it soon found out a good use to put some of these stamens to. It wanted the bees to see and come, so it changed some of its stamens into petals. The anthers ceased to grow, and they and the filaments spread out broad and bright. So, you see, petals, too, are nothing but leaves,—very much changed leaves, true, as they were first leaves, then stamens, and then petals, but that does not prevent their having come from leaves after all. If you want to see how it is done, look at a water lily next time you get a chance. Unless it is a very unaccommodating lily indeed, you will be sure to see stamens changing into petals. Some of the inside petals are small with an anther at the tip.