As in The Prairie Worm (1969) Costello sketches for the interested novice ecosystems and endemic flora and fauna of a diminishing wilderness -- here the North American desert region including the Great Basin, Mohave, Sonoran and Chihuahuan Deserts. This area is ""the most densely vegetated of the earth's arid regions"" and the author discusses the adaptive mechanisms of desert plants to water and salt levels, and typical patterns of seed dispersal. He also touches upon physiological and behavioral adjustments of the desert animals to the environment which result in a large variety of oddments -- a rabbit's heat-reflecting ears, an insect's ""wax-proofed"" surface -- and illustrate the fine interdependence of plants and animals in the limited, demanding yet sufficient habitat. There is a survey of prominent lakes and rivers, endemic ecozones and a round-up of typical plants, mammals, reptiles, amphibians and insects. Now these tight ecosystems are threatened and in some cases have been destroyed -- overgrazing has produced floods and grass loss, etc.; poisoning of predators has resulted in large increases of rodents; and military, industrial, and ""vandal"" incursions are menacing prehistoric ruins, some species and the essential balance of the desert. Costello writes plodding prose but there are 75 photographs to lighten the way through the thicket of information.