The recent historical review by van Creveld1 of the cases reported as examples of glycogen disease not only called attention to the syndrome but demonstrated the great variation in the clinical and pathologic observations. These variations are indeed so great that it is reasonable to doubt whether the cases belong to a single disease entity. The concept has been that the fundamental basis of the disease is the inability of the liver or the heart to break down glycogen, and some cases can logically be interpreted on that basis. In others of the reported cases, however, the liver released dextrose on the administration of epinephrine, and postmortem studies showed the liver tissue to be capable of breaking down glycogen. The inclusion of these cases under the heading of von Gierke's disease has obscured the problem. It seems probable that the cases reported as examples of von Gierke's disease or