The cetaceans - whales, dolphins and other related aquatic mammals - have fascinated humans for centuries. Very early these creatures of the deep became the subject of legend and coastal folk art. Yet only in the last 50 years has our scientific knowledge advanced beyond a rudimentary understanding of their anatomy and living habits. In this succinct illustrated account, the late Everhard J Slijper - for years one of the world's foremost authorities on cetacean life - introduces the reader to all facets of the biology and behavior of whales and dolphins. He carefully explains how these aquatic mammals swim, breathe and dive; he discusses their mating and social behavior, their communication, nutrition, metabolism, and reproduction; he reviews their geographic distribution and migratory patterns.