C. K. SPRENGEL, in his Entdeckte Geheimniss der Natur im Bau und in der Befruchtung der Blumen, gives an excellent account of the structure of the Common Barberry, Berberis vulgaris, and points out how it is visited by insects, and how, upon the touch of an insect's limb or proboscis, the irritable filaments move inwards, and press the opened anthers against the stigma. It is needless to recapitulate the details of structure and movements of a plant so well known, but I venture to think that there is a function and a purpose beyond those which Sprengel's ingenuity has pointed out. Sprengel's great object was to show how insects and flowers mutually help one another, and, consequently, when he had shown that the anther could not shed its pollen on the stigma until the filament was touched by an insect, and that, when so touched, the open anther became pressed against the stigma, he was satisfied. He does not seem to have been fully alive to the wider generalisation made by Mr. Darwin, that this relation of insects to flowers serves the purpose of crossing by fertilising the stigma of one flower with pollen taken from another. At any rate, in this case he has been content with the ingenuity of the apparatus for self-fertilisation through the instrumentality of an insect.