ECOLOGY, that phase of biology that con siders plants and animals as they exist in na ture, and studies their interdependence, and the relation of each kind and individual to its en vironment. It is the study of the actions and interactions of living things, and their reactions toward external influences. Although there al ways have been observers of organic nature, and collectors and recorders of facts — the material for the generalizations of biology— this information has for the most part con sisted of isolated facts only slightly correlated with the circumstances surrounding each case: and it has rarely been studied in the light shed by other sciences, as chemistry, meteorology, Feology, etc., on the physical processes attend mg growth, individual success and group-devel opment in nature. It is in this wide, synthetic method that ecologists seek to work, including in any problem all the influences that combine to produce and modify an animal or a given fauna, and thus to account for its existence and peculiarities in the place where it is found.
Ecology, then, is more than merely a study of life-history, or of habit and behavior, for it seeks to ascertain and interpret the causes of, and reason for, observed facts by gaining a knowledge of the complex influences to which the animal or plant in question is exposed, and the nature of its reactions.
It is only within recent years that this field of study has been recognized in its full value, and scientifically utilized, but the very illumi nating results obtained have converted to it many naturalists who were at first openly skep tical of its practical value. The American Ecological Society now contains more than 300 members, and in many universities and mu seums formal instruction in ecological methods is now given to students of zoology and botany. An excellent account of the subject, by Prof. Charles C. Adams, may be read in the American Museum Journal (Vol. XVII, November 1917, pages 491-494).