Note 2 — GENERAL OBSERVATIONS.

Several plants certainly possess a considerable degree of sensible organic contractility; the mimosa pudica (sensitive plant) is a well known example, though there are several others that enjoy this property to almost as great an extent; particularly the hedysarum gyrans, the oxalis sensitiva, and the berberis vulgaris. "A very remarkable degree of irritability, not exceeded by the sensitive plant, exists in the flowers of the barberry, (berberis vulgaris.) When these are fully expanded, the stamens are found spread out on the inside of the corolla. In this situation, if the inside of the filament be touched with a pin or straw, it instantly contracts and throws the anther violently against the stigma. This fact, which has been particularly described by Dr. Smith, in the English barberry, is not less remarkable and distinct in the American varieties of the shrub." Bigelow's Florula Bostoniensis. Tr.