Addisonian or idiopathic pernicious anemia is a complex disease resulting from a lack of specific factors necessary (1) for the normal growth and development of erythrocytes, (2) for the nutrition of nerves and spinal cord and (3) for the correct functioning of the gastrointestinal tract. With a deficiency of such factors (1) large uncompleted red cells stagnate in the marrow which becomes hyperplastic and red—such erythrocytes as are released into the circulation are macrocytic and so larger than normal, (2) the peripheral nerves and spinal cord degenerate from interference with nutrition and (3) the papillae of the tongue atrophy and the epithelial cells of the gastrointestinal tract become abnormal with impaired function. It is not known just how many factors are involved. There are certainly two and perhaps more. The disease was always fatal before the discovery of liver therapy. Over 10,000 persons died yearly in the United States alone