The papers presented on the opening morning of the International Neurological Congress at Bern dealt with three phases of the problem of tumors of the brain. In the first four communications certain aspects of the clinical neurologic symptoms of these lesions were considered. In the second group of papers the pathology of tumors of the brain was discussed, together with the variations in position, rapidity of growth and possibilities for complete extirpation without the recurrence noted in different types of tumors. Proper evaluation of these facts has an important bearing on preoperative prognosis and operative procedure. Lastly, mechanical methods of localization, by roentgen changes in the skull produced by the tumor, puncture of the brain and the injection of air or arterial encephalography were outlined, and the usefulness of each method was discussed. In this way the problems that present themselves in an attack on an intracranial tumor were taken