1. James Homer Wright Pathology Laboratories and Mixter Laboratory for Electron Microscopy, Neurosurgical Service, Massachusetts General Hospital, Boston, Massachusetts.
2. Clinical and Research Fellow in Pathology and Acting head, Mixter Laboratory for Electron Microscopy, Massachusetts General Hospital; Teaching Fellow, Harvard Medical School, Boston, Massachusetts.
3. Assistant Resident in Pathology, Massach uselts General hospital; Teaching Fellow, Harvard Medical School, Boston, Massachusetts.