For obvious practical reasons the subject of oncology has increasingly been becoming artificially subdivided, e.g. into epidemiology, experimental carcinogenesis, pathology, im­ munology, genetics, and even microbiology. Most extant tre­ atments of the subject are multi-authored, even when they deal with just one of these various subdivisions. Moreover, the corresponding specialists have seen the cancer problem as one within the purview of their own calling. In nature, however, the problem is a unity: its immunology, biochemistry, genetics, and cell biology, for example, are closely interdependent. Con­ sequently, its proper appraisal requires detailed examination of all of the major parts, but with the primary aim of a single-minded and hence unified survey of the whole. The present work is an offering in this direction. It is addressed specifically to all practising oncologists, whether clinical or ex­ perimental, and generally to all serious students of the growth of oncology and medicine from ancient to modern times.