ZOOLOGY, that branch of biology, or the science of living things, which treats of animals. The scope of the science may be gathered from the following enumeration of its main branches: (1) Morphology, which treats of the outer form and internal structure of animals, their anatomy, histology, physiology, etc.; (2) Embryology, or ontogeny, treating of the development of individual animals from their earliest discernible stage; (3) Threm ziatology, treating of or propagating animals and plants under domestication, of their congenital variations under these circumstances, and of the perpetuation of such variationsu; (4) Palceozoology, or animal palaeontology, treating of fossil animals. (5) Phylogeny, which seeks to investigate the evolution of the various groups or types of animals; (6) Taxon omy, or Systematic Zoology, treating of the classification of animals,— their arrangement in groups determined by genetic relationships; (7) Bionomics, or Ecology, which investigates the conditions of life as a whole, habits, instincts, etc.; (8) Zoogeography, dealing with the dis tribution of animals on the surface of the earth.
So comprehensive a view of zoology is a mod ern conception and has resulted from the con viction of the unity of organic nature and the kinship of descent which pervades the whole realm of beings, past and present In the ear lier days of the study of nature each group of animals was considered by itself, and to each such study was naturally given a name, many of which survive as convenient terms in de scriptive zoology. Such are Conchology, the study of shells (of mollusks), and hence the study of the Mollusca; Entomology, the study of insects; Herpetology, the study of reptiles (popularly including amphibians) ; Ornithology, the study of birds, and so on. For detailed in formation upon animals and the various aspects of their instigation consult articles under their names, as birds, horse, pompano, etc.; under the technical names of groups, as Carnivora, Camelida, and under such terms as Ichthyology, Herpetology and the like. See also ANATOMY;