Our time does not permit of more than a brief allusion to the subject, but in cancer patients I have so constantly found the salivary secretion acid, and often strongly so, instead of the normal alkaline or neutral, that I cannot but believe that this condition has some bearing upon the subject which we are studying; the saliva also is apt to be acid in diabetes, which is closely allied to cancer. It is to be remembered that the saliva, which amounts in health to between one and two quarts daily, varying somewhat with the food, is not wholly for the purpose of lubricating the mouth and facilitating deglutition, but its enzymes, ptyalin and maltase, effect radical and important changes in the starchy matters consumed. It is also to be remembered that the latter cannot be acted upon by the stomach secretions, but must be passed on to the influence of the pancreatic fluid in the small intestine, in case the action of the saliva has not been effective; hence there follows delayed and imperfect digestion, faulty metabolism, deranged nutrition, and possibly tumor growth. The importance, therefore, of very slow eating, thorough mastication, and perfect insalivation cannot be too strongly insisted on, both as an element of importance in the prevention of cancer, and also as a curative measure in patients in whom the diseased process has already manifested itself. The so-called _internal secretions_ have also been the subject of much research and speculation of late years, in regard to their influence on metabolism and the life processes of the economy, and many studies have been made concerning their connection with cancer, which cannot be long dwelt upon now; but there seems to be little doubt but that the secretions of the ductless glands in common have much to do with regulating the metabolism of the cells. We know, for instance, that disease of the pituitary body produces bone disorder, resulting in gigantism, that thyroid derangement results in myxœdema, and that disease of the supra-renal capsules gives rise to Addison’s disease, or bronzed skin; and it is not at all impossible that the derangement of secretion of one or more of these and other organs may be an element in the disordered action of certain epithelial cells, resulting in cancer. Harrower calls attention to the fact that cancer is essentially a disease of that period of life when certain of the ductless glands lose their normal function, this loss entailing related changes in the whole chain of interrelated functions of the ductless glands.