There are ~some quite special buds~ which we must notice, and which at first sight appear very different from real buds. They have been given a different name, and are called ~Bulbs~. Cut right through a tulip or hyacinth bulb lengthways, and compare it with a horse chestnut bud to which you have done the same. The arrangement of the parts of the two things seems to be very similar. If you examine the bulb in detail, you will find that it is protected on the outside by brown, hard scales, and that the softer leaves within are folded over each other very much like those in the true buds. Now the bud of the horse chestnut is attached to the parent stem--is there nothing corresponding to the stem in the tulip bulb? Look carefully at the base, and you will see a little mass of tissue which holds the scales together (~see~ S, fig. 68); this is the stem, which is short and very much reduced, being unlike a usual stem. There is also one great difference between the scales in the bud and the bulb. In the bud they are rather thin and dry, but in the bulb they are thick and white and very fleshy, and if you test them with iodine, you will find that they contain much starchy food. They form the storehouse of the tulip, and this food will be used by the plant when it begins to grow. In the axils of these thick fleshy leaves you may often find small buds, which will get large and fleshy by next year and form the new bulbs (~see~ fig. 68 ~b~). [Illustration: Fig. 68. Bulb cut through, showing the overlapping scales (~s~) packed with food attached to the shortened stem S. B is the bud, which will grow out into the air, and (~b~) the bud which will form a new bulb next year; (~r~) adventitious roots growing from the base of the stem.] Sometimes little bulb-like structures grow in the axils of ordinary leaves, for example, in the tiger lily; these drop off when they are ripe, and can grow into whole new plants. They are really half-way between bulbs and true buds. CHAPTER XV. FLOWERS If you have ever noticed a pea-flower fading, you will have seen that from its heart there grows a little green pea pod which ripens till there are full-grown peas in it (~see~ fig. 80); and a yellow dandelion flower turns in the end to a white puff ball which scatters a hundred floating fruits. In fact, almost all flowers which have not been spoiled by the gardeners and “over-cultivated” leave in their place when they die fruits and seeds in some form or other. ~This gives us the key to the secret of the structure of the flowers themselves.~ =They are the forerunners of the fruits=, ~containing living seed, and their structure and all their parts are adapted in some way to help in the formation of fruit~. Now let us examine the flowers, never forgetting that fact. [Illustration: Fig. 69. Flower of Harebell; (~s~) sepals; (~p~) petals.]