For all persons seriously concerned about the destruction of natural environments in the contemporary world, this book presents a comprehensive rationale for preserving wild species and ecosystems. Bryan G. Norton appeals most centrally to "transformative value," the power of human contacts with wild species to transform and uplift the human spirit. Until now species preservationists have found a theoretical basis for their policies in the "demand" value of wild species for fulfilling certain narrowly defined human needs or in controversial and badly understood proposals about the "intrinsic" values of species. This work examines such rationales and diverges from them by pointing to new sources of value for wild species: they have worth because they can transform human values. Because of the central role of biological diversity in environmental concerns, the book also provides a fresh perspective on environmental ethics more generally. Why Preserve Natural Variety? is sponsored by the Center for Philosophy and Public Policy at the University of Maryland, as was The Preservation of Species: The Value of Biological Diversity, which was edited by Professor Norton. Originally published in 1986. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.

The Mollusca, Volume 6: Ecology provides an overview of the state of knowledge in molluscan ecology. It is part of a multivolume treatise that covers the fields of biochemistry, physiology, neurobiology, reproduction and development, evolution, ecology, medical aspects, and structure. The Mollusca is intended to serve a range of disciplines: biological, biochemical, paleontological, and medical. As a source of information on the current status of molluscan research, it should prove useful to researchers of the Mollusca and other phyla, as well as to teachers and qualified graduate students. The book contains 15 chapters, arranged into three levels of ecological perspective: (a) distributional studies; (b) physiological ecology and bioenergetics; and (c) population genetics and dynamics. A discussion of the planetary distribution of and ecological constraints upon the mollusca is followed by separate chapters on the life styles and distribution of mollusks on the deep-sea bottom, in mangroves, and on coral reefs; and the trophic and reproductive ecology of those intrinsically fascinating molluscan groups—the nudibranchs and cephalopods. Subsequent chapters present physiological ecology in land snails and in freshwater bivalves, prosobranchs, and pulmonates, with a survey of the techniques of actuarial bioenergetics as applied to nonmarine molluscs. Other chapters cover population dynamics and biology in an introduced pest species, population genetics of marine molluscs, ecogenetics of land snails, and life-cycle pattems throughout the major molluscan taxa.

Sir Charles Maurice Yonge who died in 1986 was the foremost authority on the Bivalvia and one of the greatest marine biologists of this century. The volume is a memorial to his achievements and comprises 22 papers presented at a symposium in his honour during the IX International Malacological Congress, Edinburgh, Scotland, 1986. It contains 4 sections: Evolution, Feeding and Digestion, Functional Morphology, and Ecology, and will be of interest to all students of the Mollusca.