1. The Distribution of Iron in Nature.- The basic physical, chemical, and biochemical properties of iron.- 2. Biochemical Evolution of the Heme-Type Enzymes.- 3. The Biological Significance of Iron-Containing Compounds.- 4. Distribution and Function of the Iron-Containing Complexes of the Human Organism.- Heme iron compounds.- Storage iron.- Transport iron.- Other non-heme iron compounds.- 5. Dietary Iron.- Iron intake.- 6. Iron Absorption.- Factors influencing iron absorption.- The control of iron absorption.- Measurement of iron absorption.- 7. Iron Transport.- Plasma iron.- Transferrin.- 8. Storage Iron.- Ferritin and hemosiderin.- Deposition and mobilization of iron.- Quantitative aspects of iron stores.- Clinical methods used for the estimation of available iron stores.- 9. Iron Loss and Iron Requirement.- Iron loss in women.- Iron requirements for newborns, infants, and children.- 10. Erythropoiesis.- 11. Hemoglobin Synthesis.- Biosynthesis of heme.- Biosynthesis of globin.- 12. Red Cell Destruction.- 13. Hemoglobin Catabolism.- 14. Ferrokinetics.- Survey.- Plasma iron clearance and plasma iron transport rate.- Incorporation of radioiron into the erythroblasts and reticulocytes. Iron utilization in the course of red cell production. Effective erythropoiesis.- Distribution of iron among the bone marrow, liver, and spleen.- 15. Erythrokinetics.- Red cell production.- Red cell destruction.- 16. Cytochemical Stains and Microscopy.- Siderocytes.- Sideroblasts.- Sideromacrophages.- 17. Electron Microscopic Investigations.- Ferritin.- Hemosiderin.- Erythrophagocytosis.- Iron transport.- Rhopheocytosis.- Sideroblasts and siderocytes.- 18. Iron Deficiency.- Incidence.- The clinical picture of iron deficiency.- Laboratory findings.- Ferrokinetics.- The diagnosis of iron deficiency.- Differential diagnosis of iron deficiency.- Etiology and pathogenesis of iron deficiency.- Therapy of iron deficiency.- Acute iron intoxication.- 19. Anemia of Infection.- Differential diagnlC+