I have already mentioned that the most conspicuous part of the flower is merely a covering to protect the seed-producing organs from injury. In most flowers there are two of these coverings, which form together what is called the perianth; the inner one, when spoken of separately, being called the corolla, and the outer one the calyx. The corolla is generally of some brilliant colour, and in most cases it is divided into several leaf-like parts called petals, (see _g_ in figs. 2 and 3); and the calyx, which is commonly green, is divided into similar portions called sepals (see _h_). Sometimes there is only one of these coverings, and when this is the case it is called by modern botanists the calyx, though it may be coloured like a corolla; and sometimes the calyx and corolla are of the same colour, and so mixed as hardly to be distinguished from each other, as in the crocus and the tulip; in which case the divisions are called the segments of the perianth. CHAPTER I. THE ORDER RANUNCULACEÆ: ILLUSTRATED BY THE RANUNCULUS, THE BUTTERCUP OR CROWFOOT, THE PEONY, THE ANEMONE, THE HEPATICA, THE CLEMATIS, THE CHRISTMAS ROSE, THE WINTER ACONITE, MONKSHOOD, THE LARKSPUR, AND THE COLUMBINE. Such of my readers who may have formed their first ideas of the natural system from some order, the flowers of which bear a strong resemblance to each other, will be surprised at reading the names of the heterogeneous assemblage of plants at the head of this chapter; for surely no flowers can bear less resemblance to each other than the buttercup and the peony do to the columbine and the larkspur. There are, however, striking points of resemblance which link these flowers together; the principal of which are the number and disposition of the ovaries, or carpels as they are called in this case, which, though they grow close together, and sometimes even adhere to each other, are yet perfectly distinct; in the number and position of the stamens, which grow out of the receptacle from beneath the carpels; and in the leaves and young stems, when cut or pressed, yielding a thin yellowish juice, which is extremely acrid, and, in most cases, poisonous. The flowers of the plants belonging to Ranunculaceæ differ widely in their shapes; and all the incongruities that are only sparingly met with in other orders, are here gathered together. Some of the flowers have only a coloured calyx, as in the clematis; in others the calyx and corolla are of the same colour, as in the globe-flower, or so intermingled as to seem all one, as in the columbine; and in others the calyx forms the most ornamental part of the flower, as in monkshood and the larkspurs. In short, modern botanists seem to have placed this unfortunate order first, as though to terrify students on the very threshold of the science, and to prevent them from daring to advance any farther to penetrate into its mysteries. THE GENUS RANUNCULUS.