If any neurologic surgeon were asked to name the most difficult tumor to extirpate, his answer would doubtless be "the acoustic tumor." Until recent years the surgical removal of this type of growth appeared to be almost impossible. In 1917 no less an authority than Cushing1 wrote: "I doubt very much, unless some more perfected method is devised, whether one of these tumors can with safety be totally enucleated." He was content with removal of the interior of the tumor, by which life could be prolonged, although recurrence was inevitable. Nor could there be any question of the wisdom of his course, for the mortality following total removal at that time was nearly 100 per cent. Successful complete removals of tumors of this type by all of the world's brain surgeons at that time could be counted on the fingers of one hand.
It seemed incredible that a perfectly