Environmental control has been given a big boost in public relations through the activities of Secretary of the Interior, Stewart Udall, and the beautifying campaign of the current First Lady. Safe-guarding our natural splendors is no longer merely a ladies' club hobby. ""Steadily,"" remarks Professor Murphy, ""the average American seems to regard the land less as an economic object than an essentially aesthetic one."" And steadily too, alas, the problems of conservation, pollution, and urban industrial culture have mounted, producing challenges, not to say crises, concerning the regulation of renewable resources. In his own very resourceful study, Professor Murphy gives a detailed, extremely level-headed, historically minded assessment of the present ambiguous state of the water, air, and forests around us, as well as the costs, conflicts, and choices which we face. From Wisconsin to California, the native grasses have perished; the great rivers are dumping grounds; and though ""emissions are becoming smokeless...the problem is greater than it was: in the future, it will not be deposited grit but what is carried in suspension that will serve as the measure of air pollution."" One of the book's most valuable aspects is the close survey given to planning difficulties, scientific ""advances,"" and vested interests.