The problem of the absorption and excretion of iron by the gastrointestinal tract remains baffling in spite of studies by numerous investigators during many years. The conclusions of many workers that iron is absorbed by the small and excreted by the large intestine have not been confirmed by recent investigations. Wallbach,1 after repeating on mice the experiments of Hochhaus and Quincke, came to the conclusion that there is no morphologic criterion for the determination of whether iron is being absorbed or excreted, since the morphologic appearance of iron in the intestine is the same in the two instances. M'Gowan,2 from a study of the literature and from observations on fowls suffering from hemolytic anemia, came to the conclusion that there is apparently "no justification for the statements current regarding the movements of iron in the body, namely that while absorption takes place solely from the duodenum, excretion is