The world-riddle of pathology the past twenty years has been: Is cancer due to the invasion of a parasite, a veritable microscopic crab, or is it due to alterations in the communal relations, or, to speak metaphorically, the allegiance of the cells? Disappointing as it may be, the balance of proof and the opinion of the ablest and broadest-minded experts are against the parasitic theory, so far, and becoming more decidedly so. In other words, cancer appears to be an evil which the body breeds within itself. There is absolutely no adequate ground for the tone of lamentation and the Cassandra-like prophecy which pervade all popular, and a considerable part of medical, discussion of the race aspects of the cancer problem. The reasoning of most of these Jeremiahs is something on this wise: That, inasmuch as the deaths from cancer have apparently nearly trebled in proportion to the population within the last thirty years, it only needs a piece of paper and a pencil to be able to figure out with absolute certainty that in a certain number of decades, at this geometric ratio, there will be more deaths from cancer than there are human beings living. There could be no more striking illustration, both of the dangerousness of "a little knowledge" and of the absurdity of applying rigid logic to premises which contain a large percentage of error. Too blind a confidence in the inerrancy of logic is almost as dangerous as superstition. Space will not permit us to enter into details, but suffice it to say:-- First, that expert statisticians are in grave doubt whether this increase is real or only apparent, due to more accurate diagnosis and more complete recording of all cases occurring. Certainly a large proportion of it is due to the gross imperfection of our records thirty years ago. Second, that the apparent increase is little greater than that of deaths due to other diseases of later life, such as nervous, kidney, and heart diseases. Our heaviest saving of life so far is in the first five-year period, and more children are surviving to reach the cancer and Bright's disease age. Third, that a disease, eighty per cent of whose death-rate occurs after forty-five years of age, is scarcely likely to threaten the continued existence of the race. The nature of the process is a revolt of a group of cells. The cause of it is legion, for it embraces any influence which may detach the cell from its normal surroundings,--"isolate it," as one pathologist expresses it. The cure is early and complete amputation of not only the rebellious cells, but of the entire organ or region in which they occur. A cancer is a biologic anomaly. Everywhere else in the cell-state we find each organ, each part, strictly subordinated, both in form and function, to the interests of the whole.