Includes bibliographies.

The tragedy of the commons, by G. Hardin.--Why worry about nature? By R. L. Means.--Our treatment of the environment in ideal and actuality, by Yi-Fu Tuan.--The ecology of man, the animal, by S. C. Kendeigh.--Ecology, by R. M. Chute.--Nutrient cycling, by F. H. Bormann and G. E. Likens.--Inimical effects on wildlife of periodic DDD application to Clear Lake, by E. G. Hunt and A. I. Bischoff.--The toxicity of endrin-resistant mosquitofish to eleven species of vertebrates, by P. Rosato and D. E. Ferguson.--The effects of pesticides, by W. A. Niering.--Integrated biological-chemical pest control sought, by R. Manley.--Cultural eutrophication is reversible, by A. D. Hasler.--Some biological effects of oil pollution, by E. B. Cowell.--Hazards of radioactive waste, by W. C. Patterson.--Effects of pollution on the structure and physiology of ecosystems, by G. M. Woodwell.--Feedbacks in economic and demographic transition, by H. Frederiksen.--The social aspects of population dynamics, by J. B. Calhoun.--The optimum human environment and its relation to modern agricultural preoccupations, by H. H. Iltis.--The vandal ideology, by S. Paradise.--The tragedy of the commons revisited, by B. Crowe.