EVOLUTION (Lat. erointio, from e rol ve re , to unroll, from e, out rolverc, to roll; con meted with (loth. icolirjon, AS. irrobricin, Eng. ow 1 low). The evolution theory, in its broadest aspect, undertakes to explain the origin of the universe, of all created things material and im material; and more especially the origin of our own planet, together with. the plants and animals living and extinct, including man. his physical and mental nature. Applied to living beings we use the expressions 'organic evolution,' 'theory of deseent,' 'origin Of species, 'transformation of species; or 'trans:14)1111km: The theory of de scent is supported by a range of facts as wide a; the number and variety of form. of life, the spe cies of plants and animals, living or fossil, enter ing into the millions. To appreciate properly the facts and arguments on which the theory is based one must be familiar with at least the elements of all the natural seiences, especially botany, zotilogy, and geology, and have done some original work on a group of organisms. besides having sonic degree of sympathy with the a has and methods of natural science. It should be borne in mind that in this single word eroluliou is comprised a study of the mode of action of that vast complex of natural conditions which has resulted in the formation of the stars and planets. and in the stocking of our earth with
plants and animals each after their kind.
Evolution in general is based (1) on the unity of action of the processes of nature. We mean by the word 'nature' everything which has been generated, produced. or created. This, from a philosophical standpoint, implies an infinite power, or Creator, outside of and yet immanent in the material world, working by natural laws in and through matter, mind, and spirit. (2) The theory of descent, or organic evolution, is based on the principle of the unity of organiza tion in plants and animals: (3) on the fact that the living substance known as protoplasm is the physical basis of life: (4) on the fact that all movements in the plant or animal body are due to the contractility of protoplasm; and (5) to the fact that all plants and animals arise from germs, seeds, or eggs. This does not exclude the view that the first germ of life—the primitive bit of protoplasm—arose by spontaneous genera