The comparative value of whole liver, ferrous carbonate, liver extract (fraction G of Cohn) and various combinations of these substances in the treatment of secondary anemia of man was discussed in three previous communications.1The present report is concerned with observations as to the relative merit of ferric ammonium citrate, ferric citrate, liver extract for use in secondary anemia (Whipple2), solution of liver extract for intramuscular injection3and a comparison of these with the substances previously reported on for the treatment of the same type of anemia. METHODS OF STUDY Since the methods used in the study of the cases reported here have been similar in most respects to those described previously,4a complete description of them will not be repeated. Hemoglobin determinations have been made by means of the Osgood-Haskins5modification of the Sahli method. By this method, 100 per cent is equivalent to