Includes bibliographical references.

The history of water pollution -- Natural waters and natural qualities -- Ecological factors and river floras -- River faunas -- Effluents and chemistry -- Physical and chemical effects of effluents on rivers -- Biological effects of poisons -- Biological effects of simple deoxygenation and suspended solids -- Biological effects of organic matter -- Further biological aspects of organic pollution -- Heat, salts and pollution of lakes -- Other human influences on natural waters -- The biological assessment of pollution -- The prospects for the future -- References -- Subject index -- Author index. Examines and describes the various customs of North American Indian tribes to explain the evolution of man as a social being - his relationships with his family and kin groups, his religious and his political institutions. Includes Eskimos, Sub-arctic Indians, Plains Indians, Aztec Indians, and Pueblo Indians.