Malignant tumours of the brain and brain stem compel an attitude of critical optimism on the part of the neurosurgeon and the radiation therapist in their approach to the problems both of the attack upon the individual tumour and the assessment of the results in the several types of neoplasm. The constantly painstaking, sometimes bold, progress of neurosurgery over the last two decades is well known. The drama of surgery is enhanced, in this field, by the close proximity of vital structures, the often critical state of the patient, and the urgent need to avoid further damage to function. The forte of radiation therapy is more humdrum, save possibly in the medulloblastomas, and not without some disappointment and headache. But if, ultimately, it is to be found valuable in the control of extension or recurrence of brain neoplasms (which the surgeon rarely can remove in toto), a consistent pattern or method of treatment must be used intelligently in a fairly large series of cases, and then critically surveye...