We saw further that there appeared to be good evidence that certain misplaced “embryonal rests” were the original starting points of diseased cell action, but as these are now known to exist in every one from birth, this offers no real explanation of the occurrence of the disease at different times in life. It is, of course, quite possible that local injury of one kind or another may be the exciting cause which determines that a cell or group of cells shall revert to its original reproductive activity, as Williams contends that the process is one of agamogenesis, dependent upon excessive and faulty nutrition. The question as to the relation of uricacidæmia, or lithæmia, to cancer has never been fully studied, and it is worth considering whether, as in gout and rheumatism, to which cancer is often associated and perhaps closely allied, the exciting cause may not be the lodgment somewhere of uratic deposit, which is further excited and fed by effete or imperfectly oxidized nitrogenous elements; for later we shall see that perverted metabolism, largely of proteid elements, is closely associated with cancer. We noted also that some attributed cancer to independent cell action, relating to the polarity of cells, etc.; but it is inconceivable that a cell or cells can idiopathically start out on a rampant course and pursue it with increasing severity, even until death results, without, at least, some definite pre-disposing cause, even though diligent and earnest work has not as yet determined just what that cause may be. The error has been, we believe, in searching too exclusively by the microscope and by certain laboratory methods, and not sufficiently along clinical and bio-chemical lines. For it must be recognized that all the cells of the body are continually bathed in the vitalizing fluid of the blood, whence they derive their nutriment, and into which, with the lymphatics, they return the products of their vital action, by anabolism and catabolism. By exclusion, therefore, we are reduced to seek the etiology of cancer along other lines, and about all that is left is metabolism, as influenced by advancing, so-called civilization, which relates very largely to diet and mode of life. This we will take up later, but will first examine some of the scientific findings in regard to the blood in cancer, and data relating to the various secretions and excretions of the body bearing upon metabolism in this disease. That the blood shows great changes in advanced cancer is recognized by all, as is clinically manifested by the intense cachexia and anæmia commonly present and always strongly marked toward the end, of which the cytology has been very fully studied and presented by Türk. When then examined there is found to be a marked reduction of red cells, low hæmoglobin index, and distinct leucocytosis, with greatly diminished alkalescence.