In the course of an address (unpublished) before the American College of Surgeons,1 on "Brain Tumor Statistics," it was pointed out by Dr. Harvey Cushing that there was great difficulty in comparing statistics from different clinics because of the great variation in classification. It is believed that a record of the method employed in a clinic where large numbers of such cases are handled will be of value. The routine series entering the Peter Bent Brigham Hospital between April 1, 1919, and Dec. 1, 1919, has been chosen, all these cases having been under my personal supervision.
There were admitted between the dates given, 118 patients supposed to be suffering from some sort of intracranial new growth involving the brain. Some of the difficulties involved in classification may be appreciated from the following history which will be, in common with all the succeeding ones, condensed to positive findings, omitting