The fact that systemic infection may lead to significant metabolic changes in the host has long been appreciated by clinical observers, who are trained to focus their attention on the whole organism rather than on a given bacteriologic, immunologic or pathologic phase of the disease. In contrast to this, in the study of experimental laboratory infections workers have been so preoccupied with the investigation of specific phenomena of defense, as seen in the altered reactivity of serum and tissue cells, that they have lost sight, as a rule, of the many correlated changes of metabolic nature which assume great significance for a better understanding of the intricate mechanism of the morbid process. Only in recent years, for example, have serious efforts been made to elucidate the nature of diphtheritic intoxication by systematic analysis of disturbances in the carbohydrate metabolism. Among the most important results obtained by a large group of