IN 1968, Bucy and Thieman1 reported a long-term study which confirmed the general opinion that astrocytomas of the cerebellum are among the most benign and most favorable of all brain tumors. At that time they studied a group of 24 patients who had suffered from such tumors, 22 of these patients having undergone surgical treatment prior to 1938. However, there were unfortunate aspects in that series of cases; notably, a serious residual impairment of vision in seven out of the 17 patients available for follow-up and an unacceptably high postoperative mortality of 23%. If the two patients who died without being operated upon are included, the mortality for that group became 29%. Even though it was felt that the results in the 24 cases then reported were gratifying for that period, 1928 to 1938, it was believed that in the past 30 years the results of treatment had