Morphology
that branch of natural science which treats of the laws, form, and arrangement of the structures of animals and plants, treating of their varieties, homologies and metamorphoses; that most organs of a plant, including the science of form. Morphology teaches the bracts, sepals, petals, stamens, and pistils, are modifications of leaves. With regard to animals, it investigates the tissues of which their structures are composed, the states through which each animal has to pass before reaching maturity, and the modifications of form which the same organ undergoes in different animals. For instance, the hand of a man, the forefoot of a mole, adapted for digging, are only modifications of one type. Morphology treats also of serial homologies in the same animal, and of homogeneous and homoplastic homologies of organs.