In the era of undernutrition in diabetic therapy, low blood sugar was observed in several cases of severe diabetes.1With the introduction of insulin, "the symptom-complex hypoglycemia" became of more general interest.2It was appreciated both then and later3that symptoms were not an invariable accompaniment of low blood sugar; many authors have shown that they appear at varying levels.4 The syndrome of spontaneous hypoglycemia without diabetes was described in 1924 by Harris,5who thought it due to hyperinsulinism or dysinsulinism. Wilder, Allan, Power and Robertson6three years later published full clinical, biochemical and pathologic studies of a case of severe hypoglycemia arising from carcinoma of the pancreatic islands with metastases. The liver in this case was loaded with glycogen, but injection of epinephrine as well as of pituitary extract failed to elevate the blood sugar. When these extracts fail to elevate low blood