CONTENTS Introduction Incidence Etiology A. The neurogenic explanations B. The endocrine explanation Thyroid, suprarenals, pancreas and hypophysis The Relation of the Pancreas to Glycosuria The Relation of the Hypophysis to Glycosuria Counteraction of pituitary extracts and insulin Sugar Tolerance Tests of Acromegalic Patients Without Glycosuria The Course and Prognosis of Acromegalic Diabetes The Effect of Operations on Sugar Tolerance in Acromegaly A. With existent melituria B. With hyperglycemia in the absence of melituria Summary and Conclusions INTRODUCTION In preceding papers in this series the subject which we here propose to discuss more in detail has already been touched on. It has been stated1that in our series of 100 personally observed cases of acromegaly one out of four has shown glycosuria, and approximately one out of eight proved to have clinically outspoken diabetes mellitus. It has also been stated, in