Two general titles on the mammals of North America, both heavily illustrated, offer the nature lover easy access to basic information on physical characteristics, habits and habitat, reproduction. The Caras book is the bigger, the more exacting and extensive. For the observing nature lover, it provides tips (""In literally one word, blend"") throughout, directing its material with observation in mind (appearance and distinguishing characteristics). It covers sixty-three mammal families (The Fur-bearing Animals of the U.S. and Canada) from ancient opossum to new nutria, tiny aplondontia to great bison. 138 photographs (4 in color), 152 charts and diagrams; bibliography; index. Mr. Rue, a naturalist and lecturer, author of Cottontail and The World of the Beaver, is more the writer. His capsule commentaries are personalized, stand accompanied by 110 photographs, 65 maps of ranges, 65 especially prepared track charts. Bibliography and index, and a listing of the orders, families and species of North American wildlife. Both are popular calls of the wild. Reviewed from the texts alone.