(d) A central pistil, shaped somewhat like a slender bottle. At the top, where the cork would come in a real bottle, is the notched stigma, slightly sticky. The neck is called the style, and the part corresponding to the body of the bottle is the ovary. Tear open the ovary with a needle to see the ovules, which in an undisturbed flower would have become seeds. Watch bees visiting flowers. Does each bee confine itself to one kind (species) of flower at each journey, or does it visit several kinds indiscriminately? Try to discover what the bees are doing. Avoid alarming them. The work of flowers.—The roots, stem, and leaves of a plant do a great deal of work, but, as it is performed for the benefit of the plant itself, it is all, in a sense, selfish work. Plants, however, like animals, grow old in time, and at last die. If they are not to become extinct it is evident that they must devote part of their energies to producing new individuals, and to sending these forth into the world as well equipped as possible for the battle of life. This unselfish and self-sacrificing part of a plant’s life-work is called reproduction; in the higher plants it is carried out by flowers. The structure of a wallflower blossom.—The flowers of different groups of plants vary greatly in structure, but a good general idea of the arrangement of the parts of a flower can be obtained by examining the blossoms of a wallflower plant (Fig. 58). Other flowers may afterwards be compared and contrasted. [Pg 90] Fig. 58.—Wallflower. A, branch, bearing leaves and flowers; B, flower; C, longitudinal section of flower; D, stamens and pistil; E, fruit; S, transverse section of stem, (× ½.) There are evidently at least eight leaves in the flower, but, unlike the green foliage leaves, these are not arranged spirally, but stand at nearly the same level on the end—called the receptacle—of the flower-stalk. The most external leaves are four in number, small, narrow, and purplish in colour. Each of these leaves is called a sepal, and the four sepals together constitute the calyx of the flower. Two opposite sepals are pouched at the base, forming pockets, in which a sugary fluid, called nectar, collects. Before the [Pg 91] bud opens, the calyx is the only part of the flower which is visible. It is probably developed in the wallflower solely for the protection of the more delicate structures within. Next, inside the sepals, placed alternately with them, and standing a little higher on the receptacle, are four showy leaves arranged in the form of a Maltese cross. These leaves are called petals, and the four petals together form the corolla. The petals are delicately scented, and their surfaces have a beautiful velvety sheen.