The character of an embryo in organic beings is that it contains, in a rudimentary state, all the organs of which the organic being is composed in its entire developments. Thus, in the animal, the uterine fœtus is composed of the head, the trunk, and the extremities; in other words, of all the parts of which the adult animal is composed. In like manner, the embryos of plants, like those of animals, contain all the parts which compose the fabric of the fully developed plant in a rudimentary condition. The embryo of a bean, for example, consists of a plumule or young stem, a pair of leaves or cotyledons, and a radicle or young root, or the entire plant in a rudimentary state; and, by the act of germination, analogous in its effects to the commencement of life in the extra-uterine fœtus, all the parts of the plant develop themselves into their wonted figure and hues, in accordance with those _peculiar_ organic laws to which the plant is subjected. But germination does not increase the number of these parts, which existed before its influence was exercised on them. Now, plants have sexes, or sexual organs, as well as animals. The female sexual organs in plants are named carpels. The pistil, already described, consisting of stigma, style, and germen, is only a fully developed carpel. The male sexual organs are named stamens, the anthers of which contain the pollen or fecundating matter. The stamens and carpels are therefore the essential organs of reproduction in plants, since it is by the mutual action of these bodies that the embryo of the future plant is formed, and the same form of life continued in the earth. Fig. 1 is a representation of a petal, stamen, and the pistil of Berberis vulgaris, or the common barberry. In this plant, the anthers open by two valves to let out the pollen. These valves are seen in the figure, and the pistil is exhibited in section, to show the ovules in the cavity of the germen. [Illustration: Fig. 1.] The reproductive organs only appear at the epoch when plants attain the full development of all their parts, or arrive at an adult state. The period when this occurs varies greatly in each species, and depends entirely on the peculiarities of its constitution. When this epoch arrives, a visible change takes place in the organic functions; the stem ceases to elongate, and its internodes no longer developing, the leaves remain crowded together in closely approximated whorls, and, after undergoing those peculiar modifications in form and coloring which we have already described, a flower is produced.