In the Neurosurgical Clinic of the University of Pennsylvania Hospital there are records of sixty-two verified cases of tumor of the cerebellopontile angle. Two of these are cases of bilateral acoustic neurofibromas, one of which was associated with generalized neurofibromatosis while the other was not. This survey was suggested by a statement in the history in the latter case which intimated deafness and blindness in a number of the family connections for five generations. It so happened that eleven of the twelve members of the second generation of this family migrated to another state, so that this survey covered chiefly the direct descendants of only one of the original twelve progenitors. In this family there were thirty-eight cases of bilateral deafness; fifteen of these persons subsequently became blind. In each case in which a history was obtainable it was found that headache and vomiting preceded the blindness. From the evidence