1132. To form, new varieties of vegetables, as well as of flowers and of useful plants of every description, it is necessary to take advantage of the sexual differences, and to operate in a manner analogous to crossing the breed in animals. Hence the origin of new sorts of fruits. Even this practice is but an imitation of what takes place in nature by the agency of bees and other insects, and the wind; all the difference is, that man operates with a particular end in view, and selects individuals possessing the particular properties which he wishes to perpetuate or improve. New varieties, or rather subvarieties, are formed by altering the habits of plants ; by dwarfing through want of nourishment; variegating by arenarious soils ; and in giving, or rather continuing, peculiar habits when formed by nature, as in propagating from monstrosities-fasciculi of shoots, weeping shoots, shoots with peculiar leaves, flowers, fruit, &c.