incalculable advantage from the exercise of human skill in the improvement of yet untamed forms of vegetable life.] But it is, in every case, a question of evidence. The only satisfactory proof that a given wild plant is identical with a given garden or field vegetable, is the test of experiment, the actual growing of the one from the seed of the other, or the conversion of the one into the other by transplantation and change of conditions. [Footnote: The poisonous wild parsnip of New England has been often asserted to be convertible into the common garden parsnip by cultivation, or rather to be the same vegetable growing under different conditions, and it is said to be deprived of its deleterious qualities simply by an increased luxuriance of growth in rich, tilled earth. Wild medicinal plants, so important in the rustic materia medica of New England--such as pennyroyal, for example--are generally much less aromatic and powerful when cultivated in gardens than when self-sown on meagre soils. On the other hand, the cinchona, lately introduced from South America into British India and carefully cultivated there, is found to be richer in quinine than the American tree.] It is hardly contended that any of the cereals or other plants important as human aliment, or as objects of agricultural industry, exist and propagate themselves uncultivated in the same form and with the same properties as when sown and reared by human art. [Footnote: Some recent observations of Wetzatein are worthy of special notice. "The soil of the Hauran," he remarks, "produces, in its primitive condition, much wild rye, which is not known as a cultivated plant in Syria, and much wild barley and oats. These cereals precisely resemble the corresponding cultivated plants in leaf, ear, size, and height of straw, but their grains are sensibly flatter and poorer in flour."--Reisebericht uber Hauran und die Trachenen, p. 40.