WHEN adenomas of the pituitary gland first began to be diagnosed during the last decade of the nineteenth century the only method of relieving the pressure on the optic nerves and chiasm was by some type of surgical procedure. In those early days the intracranial approach proved too hazardous, and most surgeons soon made use of a transphenoidal operation in the development of which Dr. Oscar Hirsch, of Vienna (now of Boston), was one of the pioneers. In the late 1920's the intracranial procedure became much more perfected, and most neurosurgeons since that time have utilized this method, believing that . . .