1. Department of Medicine, George Washington University Medical School, Washington, D. C., and the Department of Hematology, Walter Reed Army Institute of Research, Walter Reed Army Medical Center, Washington, D. C.
2. George Washington University Medical School, Washington, D. C.
3. George Washington University Medical School, Washington, D.C.
4. U. S. Army, Director, Divi.si#{252}n of Medicine and Department of Hematology, Walter Reed Army Institute of Research, Walter Heed Army Medical Center, Washington, D. C.