Flagellated protozoa are important in two biological disciplines. In evolutionary biology, flagellates are critical to understanding the origins of eukaryotic cells and their diversification as protists and subsequently as plants, animals, and fungi. Flagellated protozoa also play a key role in aquatic ecosystems, where they regulate bacterial numbers and control the remineralization of nutrients. The aim of this volume is to provide a synthesis of information on these organisms. Chapters deal with the organization, diversity, ecology, and maintenance of free-living flagellates. Each chapter is written by a recognized authority in their field. The book will be of interest to protozoologists, protistologists, evolutionary biologists, and ecologists dealing with aquatic or soil ecosystems.