In the lecture which I had the honor to deliver a few weeks ago before the New York Academy of Medicine, I explained that human diabetes mellitus was a disease of highly complicated nature. I then took the stand that we should not seek in the pancreas the sole cause of the disease, but rather that a rôle is also played therein by other organs which elaborate internal secretions, and especially by the nervous system. In most general terms I defined the diabetic disturbance of metabolism as a lack of equilibrium between carbohydrate mobilization and carbohydrate combustion, arising from insufficiency of the pancreas or from overactivity of the chromaffin system, or from both causes together. Apart from the rare cases in which grave pancreatic disease has been found, we are at present ignorant of the ultimate cause of this disturbance of metabolism, and accordingly a causal therapy, the