Parts three and four of a six-volume set on the evolution of vertebrates, with over 1,000 illustrations in full color. Because the volumes lack indices and glossaries and the essential information is presented on end papers, these will be most useful for browsing. And the technical language makes it helpful to have a dictionary at hand--e.g., ""But starting with the amphibians, vertebrae acquired inferior and superior articular processes in the vertebral arch (zygapophyses), which gave the spinal column a rigid continuity."" The characteristics, evolution, and current survivors of amphibians and reptiles are discussed. Each two-page spread provides brief text plus four to six captioned illustrations. Young nature-browsers will enjoy the detailed drawings of the internal anatomy of frogs, toads, salamanders, lizards, turtles and snakes. Also intriguing are drawings of how turtle and tortoise pull into their shells; how snakes and lizards move; how frogs and salamanders use their tongues to capture food; and how the midwife toad cares for its young. There is some lurid writing: the author describes the ""atrocious habit"" of the spadefoot toad tadpoles, which ""become cannibals and begin eating up their own brothers."" And there are some editing problems, such as the two-color diagram that shows the fossil distribution of apodes but fails to indicate which color represents fossil finds. All in all, the colorful illustrations in these volumes make them appealing for science browsers, but the difficult language and lack of indices will limit their usefulness for reference and school assignments.