In 1935 Mason and Turner1 reported a carefully studied case of prolonged galactosuria with associated nutritional and developmental disturbances in an infant. Theirs was the second case of such a condition to be described, the first having been reported by Göppert2 in 1917. In both cases the outstanding clinical symptom was failure of the infant to gain and grow properly, and the chief abnormalities observed were enlargement of the liver and spleen and presence ot galactose and albumin in the urine as long as the child received any considerable amount of milk. Both patients exhibited normal tolerance for dextrose and levulose but greatly decreased tolerance for lactose and galactose. Removal of milk from the diet resulted in remarkable improvement in both instances. Intensive study of the carbohydrate metabolism of their patient led Mason and Turner to postulate that galactose was apparently absorbed normally but failed to be converted