In one golden age of medicine epitomized by William Osler, the physician also aspired to mastery of gross and microscopic pathologic anatomy. Now another such age has dawned in which ultrastructure and immunopathology provide insights into mysterious diseases of the kidney, connective tissues, joints, and muscles, among other sites. Dr. Anil K. MandaI has a background in clinical nephrology, experimental pathology, and diagnostic pathology of renal diseases that suits him well for his chosen task. This is to explain clearly the clinicopathologic entities seen by nephrologists, using the full range of available morphologic techniques. His ap- proach is brisk and incisive. To read his monograph as a pathologist is to make oneself a better clinician, and as a physician is to improve one's grasp of pa- thology. Such correlative knowledge seems at present the means most likely to lead to the ultimate control of some crippling chronic renal diseases. Sheldon C. Sommers, M.D.