The Cruciferous plants form so natural an order, that when one of them has been described the others may be easily recognised. They have all a separate calyx and corolla, each in four divisions; the four sepals being placed alternately with the four petals, the latter forming a cross (as shown at _a_ in _fig._ 113), whence the name of Cruciferous, which signifies cross-bearing. There are six stamens (_b_), two of which are much shorter than the others; and two carpels with one style, and a capitate or divided stigma. The seed-vessel is a kind of pod, either short and broad, like that of the Shepherd’s Purse (_fig._ 114), where it is called a sillicle; or long and narrow, like that of the Cabbage, which is called a silique. The two valves of the silique open naturally when ripe, from the bottom curving upwards, (see _fig._ 115,) and the seeds are deposited on a thin membrane between the cells, which is the dissepiment. All the Cruciferæ, from abounding in nitrogen, have an unpleasant smell when decaying, like putrid flesh; and when cultivated, they even in a wild state require abundance of animal manure; hence, they are generally found near human habitations, or where cattle are kept. When wild, they have generally acrid properties; and though these are in most cases softened by cultivation, yet they are still perceptible in the roots of the Horse-Radish, and the common Radish, and in the leaves and seeds of Mustard, and the different kinds of Cress, &c. This acridity, however, is never so great as to be injurious; and Cruciferous plants, particularly if their texture be succulent and watery, may always be eaten with perfect safety. Even those which, in a wild state, are tough and stringy, such as the wild Cabbage and the root of the wild Turnip, become excellent by cultivation; and all Cruciferous plants are so extremely nourishing as to be considered next in this quality to animal food. [Illustration: FIG. 115.—A SILIQUE.]