Many papers have been written concerning heredity as a factor in the development of tumors in the human body. Blank,1in 1941, reviewed the role of genetics in cancer research. Recently, we had occasion to treat the fourth member of a family to have a tumor of the brain. The occurrence of tumor of the brain in 4 members of one family strongly suggests a familial tendency in certain types of cerebral neoplasms. The predominating type of tumor identified in our cases was hemangioblastoma of the cerebellum. Cushing and Bailey,2in 1928, described at length many cases of this tumor. These growths were classified as simple cyst or gliomatous cyst until portions were removed for microscopic examination and a diagnosis of hemangioblastoma was made. The neoplasm occurs almost exclusively in the cerebellum, is usually cystic and has a familial tendency (Sargent and Greenfield3). Characteristically, but not always,