viii Preface 



great, and no attempt at any exhaustive treatment of the subject is 

 made here. Rather, this book presents an introductory account of the 

 fundamental relationships of ecology upon which an understanding 

 of the life of the individual and of the community depends. Since 

 many of these relationships are seen in a relatively simple form in the 

 marine environment, many illustrations are taken from marine habitats. 



The book is written primarily for students in ecology. It is also 

 intended as background material for those interested in conservation, 

 forestry, agriculture, fisheries, wildlife management, and other 

 branches of "applied ecology." The general biology student should 

 also derive value from the book since a knowledge of the principles 

 governing the real lives of animals and plants in nature is a vital 

 backdrop for problems in physiology, morphology, genetics, and 

 evolution. Furthermore, it must be remembered that every one of us 

 is an organism with an environment and that each of us forms part of 

 the environment for other living beings. The general reader, as well 

 as the biology student, is interested to know how the world of life 

 works. Populations of men follow many of the same laws as popula- 

 tions of microbes. The need for a knowledge of the proper adjust- 

 ment among men and between man and his natural environment was 

 never greater than it is today. 



The material of the book is drawn in large part from a course in 

 ecology given by the author at Harvard University. Many ideas and 

 illustrations have been derived from discussions with colleagues at 

 Harvard University, the Woods Hole Oceanographic Institution, and 

 elsewhere, and acknowledgment is made of this material. I am also 

 indebted to W. C. Alice, S. A. Cain, J. T. Curtis, R. W. Dexter, W. H. 

 Drury, E. H. Graham, D. R. Griffin, H. C. Hanson, A. G. Huntsman, 

 S. C. Kendeigh, B. H. Ketchum, P. C. Lemon, D. Merriman, R. S. 

 Miller, E. W. Moore, E. T. Moul, O. Park, T. Park, H. M. Raup, 

 A. C. Redfield, F. A. Richards, G. A. Riley, J. H. Ryther, P. S. Sears, 

 J. G. Steel, H. C. Stetson, and J. M. Teal for reading parts of the 

 manuscript and offering helpful criticisms. I am particularly grateful 

 to Marion S. Clarke, Donald Kennedy, and J. E. G. Raymont for 

 assistance in preparing the manuscript and for many valuable 

 suggestions. 



August, 1954 



George L. Clarke 



