The drug called Ipecacuanha is the produce of two plants belonging to this order, _Cephælis Ipecacuanha_ and _Richardsonia scabra_; though a spurious kind is made from the roots of three species of Viola, all natives of South America, and a still inferior one from the roots of a kind of Euphorbia, a native of Virginia and Carolina. It is important to know this, as the best kinds possess tonic properties as well as emetic ones, while the inferior kinds are only emetics, and they are very injurious if taken frequently. The best brown Ipecacuanha is the powdered root of _Cephælis Ipecacuanha_; a plant with small white flowers collected into a globose head, which is shrouded in an involucre closely resembling a common calyx. The true calyx to each separate flower is small and roundish, with a very short five-toothed limb. The corolla is funnel-shaped, with five small bluntish lobes. The anthers are inclosed in the corolla, and the stigma, which is two-cleft, projects only a little beyond them. The berries are two-celled and two-seeded, and they retain the lobes of the calyx. The root is fleshy and creeping. _Richardsonia scabra_, which produces the white Ipecacuanha, has its flowers also in heads, but the calyx is larger in proportion to the corolla, and the stamens and style are both visible. The capsule contains three or four one-seeded nuts, crowned by the calyx; which, however, becomes loosened at the base, and falls off, before the seeds are quite ripe. Cephalanthus, Spermacoce, and Crusea, are nearly allied to Richardsonia. The above plants all agree, more or less, with Cinchona, in their qualities, and they are all included by Dr. Lindley in the order Cinchonaceæ. THE GENUS GALIUM AND ITS ALLIES.