over, ere these pages are printed some investigator will probably have gotten new evidence of importance. There is much reason to believe that we are approaching the time when a larger and truer viewpoint with reference to man and his welfare is possible. The chemist is no longer solely concerned with the study of the properties of matter and its compounds but is interested in the results of his studies on society; the ethnologist no longer merely makes collections of curiosities of savage tribes, but seeks to explain the course of social evolution; the historian no longer enthuses over dates and names, but seeks to trace the forces at work in shaping societies; the psychologist is turning from the description of mental phenomena to a consideration of human conduct. May we not anticipate sooner or later the appearance of the man who will do for the present century what Spencer sought with considerable success to do for the last, namely, correlate existing knowledge and show its bearing on man and his institutions? I doubt if that man is now living, or, at least, has reached maturity, but he is sure to come, for after all life is a unity and human welfare our greatest concern. If in any small way I have helped to suggest that unity and the desirability of such correlation I am well content. Finally, I hope that I have succeeded in conveying the thought of the various sections without undue use of technical terms. I trust, therefore, that the general reader may find it worth while and at the same time that it may prove useful in clubs and classes which expect to make more detailed studies of some of the questions suggested in the later chapters. Barring a few exceptions books only are included in the bibliography. It seldom happens that a book is twice listed though many of them cover the discussion of several chapters. In undertaking such a study a writer has his choice of two methods. He may undertake to tell the story in his own words or may allow the authorities to speak for themselves. The first method makes the reading somewhat easier. Inasmuch as no one can claim to have first hand information on so many subjects the reader is likely to wonder if the facts are as represented. I have preferred the second method, therefore, and have quoted freely from the best works known to me. Whenever possible I have drawn freely from the books of special value. Thus some pages of Chapter IV have been taken almost verbatim from the monumental work of A. D. White, "The Warfare of Science with Theology." Special permission has been received from the following authors and publishers for quotations taken from works indicated: DEXTER, E. G. Weather Influences. Macmillan Company. WHITE, ANDREW D. Warfare of Science with Theology. D. Appleton and Co. CHAPIN, F. STUART. Social Evolution. The Century Co. SHELFORD, V. E. Animal Communities in Temperate America. Press of Chicago University. HUNTINGTON, ELLSWORTH. Civilization and Climate. Yale University Press. CATTELL, J. MCKEEN. Article in The Independent, Sept. 27, 1915. So many friends have helped me in so many ways that detailed statement is impossible. To them I owe the possibility of preparing these pages for the printer, and their assistance is gratefully acknowledged. Philadelphia, Pa. CARL KELSEY. CONTENTS Cosmic Evolution. The properties of matter which make life possible. How nature controls organisms. The conception of the organism as a machine; the wel- fare of the whole turning on the proper functioning of each part. Adaptation. Effects of air, water, heat, light on the reproduction, growth and distribution of organisms. Influence of the physical world on man: 1. Distribution and migration; 2. Occupation; 3. Phys- ical characteristics; 4. Physiological effects; 5. Psy- II. MUTUAL AID AND THE STRUGGLE FOR EXISTENCE The interdependence of all forms of life. The serv- ices rendered to animals and man by bacteria and plants. The fixing of nitrogen. The production of food. Complex series of interrelations in the animal world reaching from the lowest to highest forms. An- imal communities. Ecology. Mutual aid. The rapid possible increase of lower forms through reproduction. The fairly stationary total amount of life. The strug- gle for existence. The result of mutual aid and the struggle for existence is a balance. This balance easily upset by man: (a) by the cultivation of fields and cut- ting of forests; (b) by the introduction of new types of cultivated plants and domestic animals; (c) the acci- dental importation of pests; (d) by the careless destruc- tion of birds or other animal friends. Illustrations from recent changes in America. Government regula- tion of importation and transportation of plants and animals and of killing of migratory birds. The neces- Man's position due entirely to his ability to utilize facilities offered by nature. Civilization is based on control. Control - the possibility of directing nature. 1. Control of natural resources and forces. Primitive inventions extended man's powers in time or space. The bow and arrow. The art of fire-making. Discov- ery and use of metals, coal, iron and electricity. Rapid growth of manufacture. Synthetic chemistry. 2. The control of plants and animals. Discovery and cultivation of plants. Origin of cultivated plants. Development of new types. Domestication of animals. Relation of domestic animals to civilization. The be- ginnings of the care of fish, oysters and lobsters. 3. The control of contagious diseases. Recent dis- coveries of the causes of disease and methods by which Comparison of speculation and research. Scientific work of the ancient world. The ages of speculation. Gradual growth of a concept of evolution as opposed to a series of special creations. The work of Lin- næus, Buffon, Lamarck. The culmination in Darwin and Wallace. The acceptance of evolution by intelli- gent men. Arguments for natural selection. The re- A summary of existing information in three fields: ism begins as a single cell. The discovery of the chro- mosomes; their part in heredity. A survey of the work of Mendel and his emphasis on "unit characters"; |