D URING the past decade considerable interest has centered around the use of banana, both fresh and in' the powdered form, in infant feeding'. The digestibility of these products has been amply demonstrated, but aside from this feature other interesting and as yet unexplained facts have come to light. For example, the almost specific action of banana in cases of celiac disease and the peculiar tolerance of the diabetic patient for banana carbohydrate. Taking cognizance of these facts, we are naturally interested in knowing why they are so. In the case of the diabetic we are at a loss even for an approach to the problem, whereas the celiac child with his derangement of digestion, metabolism, and intestinal bacteriology offers a more fertile field for investigation, albeit cases of celiac disease are now great rarities. Haas I was the first to introduce banana powder in the diet of patients with celiac disease and demonstrated a marked improvement in these children. Their tolerance for the fresh fruit, for example, was such that in certain instances as many as forty bananas a day were eaten with relish and without intestinal disturbances. Surely that shows a remarkable tolerance. What, then, is the effect, if any, of banana or banana powder on tile intestinal flora of infants? I(ahn 2 reported observations on the changes in the fecal flora of seven normal infants receiving, after a preliminary normal diet control period, formulas in which an ordinary carbohydrate (5 per cent cane sugar) was changed to 5 per cent banana powder. ]~Ie noted a change in the flora of from 0 per cent gram-positive organisms during the control period to 90 per cent or over, gram-positives after twenty to twenty-five days of the diet with the banana powder supplement. Such observations in the normal infant would suggest a possible explanation of the action of banana carbohydrate in celiac disease. In this s tudy we have a t tempted to duplicate, if possible, Kahn ' s results, adhering closely to his technic and method of feeding with only slight modifications. Our group consisted of ten infants ranging in age from one week to eight months, all normal with respect to their gastrointestinal t racts and free from other disease; they were chosen principal ly because they were to remain in hospital for a sufficient length of time to enable us to complete the study. Method of Procedure.--During our prel iminary control period, which ranged in durat ion f rom ten to th i r tyfour days, with an average of