Includes bibliographical references and index.Introduction, by T. C. Chamberlin.--Fifty years of Darwinism, by E. B. Poulton.--The theory of natural selection from the standpoint of botany, by J. M. Coulter.--Isolation as a factor in organic evolution, by D. S. Jordan.--The cell in relation to heredity and evolution, by E. B. Wilson.--The direct influence of environment, by D. T. MacDougal.--The behavior of unit characters in heredity, by W. E. Castle.--Mutation, by C. B. Davenport.--Adaptation, by C. H. Elgenmann.--Darwin and paleontology, by H. F. Osborn.--Evolution and psychology, by G. S. Hall.Mode of access: Internet