The well-known medicine called Peruvian bark is produced by three species of the genus Cinchona; the pale bark, which is considered the best, being that of _C. lanceolata_. The flowers of this species are small, and of a very pale pink. The calyx (see _a_ in fig. 36) is bell-shaped, and five-toothed; and the corolla (_b_) is tubular, with the limb divided into five lobes, and silky within, as shown in the magnified section at _c_. The stamens (_d_) have very short filaments, which are inserted in the throat of the corolla. The ovary (_e_), which is deeply furrowed when young, is inclosed in the calyx; it is two-celled, with a single style, and a two-lobed stigma (_f_). The capsules retain the lobes of the calyx as a sort of crown (_g_); and they open naturally at the division between the two cells, as shown at _h_, beginning at the base. The cells (_i_) each contain several seeds. _C. oblongifolia_, which yields the red bark of the shops, has cream-coloured flowers, as large as those of a Jasmine, which they resemble in shape; and _C. cordifolia_, which produces the yellow bark, has flowers like the first species, and heart-shaped leaves. The singular plant called _Hillia longiflora_, is nearly allied to Cinchona; as is also the beautiful and delightfully fragrant _Luculia gratissima_. In this last plant the tube of the calyx is very short, and pear-shaped, and the segments of the limb are short, and sharply pointed. The corolla is salver-shaped, with a long tube, and a spreading, five-parted limb. The anthers are nearly sessile, and the short filaments to which they are attached are inserted in the throat of the corolla, only the tips of the anthers being visible. The stigma is divided into two fleshy lobes, and the capsule splits, not like that of Cinchona, but from the apex to the base in the centre of each cell. The seeds are very small, and each has a toothed, membranous wing. The flowers of this beautiful plant are produced in a large head, and at first sight greatly resemble those of a Hydrangea; but they are easily distinguished by their delightful fragrance. _Manettia cordifolia_, a very pretty stove-twiner often seen in collections, is very nearly allied to Luculia, differing principally in the shape of the flowers, which in Manettia have a long tube and a very small limb. _Bouvardia triphylla_ and the other species of Bouvardia, and _Pinckneya pubescens_, belong to this division; and such of my readers as have the living plants to refer to, will find it both interesting and instructive to dissect them and compare the parts of their flowers with the description I have given of Luculia and Cinchona, so as to discover the difference between the different genera; afterwards reading the generic character of each given in botanical works, that they may see how far they were right. THE GENUS GARDENIA AND ITS ALLIES.