1. The results of transfusions of whole plasma and blood on the fecal urobilinogen excretion of 5 children with sickle cell anemia have been reported.
2. The phenomenon observed by Josephs—a reduction in urobilinogen output following plasma transfusions—has been confirmed.
3. It has been observed further that in certain patients the continued use of plasma transfusions induces a reversal of this phenomenon, namely an increase in urobilinogen output after each transfusion.
4. The possible significance of these phenomena is discussed and attention is called to the limitations inherent in accepting urobilinogen excretion as a valid index of hemoglobin destruction in certain disorders in which a defect of hemoglobin metabolism may be present.