Structure

Living matter may be regarded under four aspects: structure, distribution, physiology, evolution. For the first, the article Morphology (Vol. 18, p. 863) leads the discussion, followed by Cytology (Vol. 7, p. 710), and Embryology (Vol. 9, p. 314), in which the growth of cell structures is discussed. These articles are introductory to the whole subject. Supplementing them reference may be made to the Morphology sections of the articles Plant (Vol. 21, p. 728) and Zoology (Vol. 28, p. 1022).

Distribution

A most fascinating branch is that which is concerned with the where and when of the existence of organisms. The articles in the Britannica are worthy of the interest of the subject. Under Palaeontology (Vol. 20, p. 579) H. F. Osborn, Columbia University, New York, president of the American Museum of Natural History, New York, treats of the archaeology of the biological sciences, of the extinct species which once inhabited the earth; while Clement Reid, of the Geological Survey of Great Britain, A. C. Seward, professor of botany, Cambridge University, and Dr. D. H. Scott, president of the Linnean Society, perform the same service for plant life in the article Palaeobotany (Vol. 20, p. 524). The distribution of present types is discussed under Zoological Distribution (Vol. 28, p. 1002), Plants, Distribution (Vol. 21, p. 777), and Plankton (Vol. 21, p. 720), in which Prof. G. H. Fowler of University College, London, describes a science which is still young—that of tracing the drift and distribution of deep sea life. See also Acclimatization (Vol. 1, p. 114), by Alfred Russel Wallace and Frank Finn, of the Indian Museum of Calcutta.

Physiology

The properties, processes, and functions of living things fall in the province of Physiology (Vol. 21, p. 554), and kindred articles; among the latter the following may profitably be consulted: Animal Heat (Vol. 2, p. 48), and Plants, Physiology (Vol. 21, p. 744).

Evolution

The gradual development of species is considered in a number of valuable articles such as Evolution (Vol. 10, p. 22), Heredity (Vol. 13, p. 350), Reproduction (Vol. 23, p. 116), Mendelism (Vol. 18, p. 115), Telegony (Vol. 25, p. 509), Variation and Selection (Vol. 27, p. 906).

Following is an alphabetical list of the general biological articles (those not dealing directly with either Botany or Zoology), which are to be found in the Britannica: