Despite long years of study, pathologists not only are ignorant of the causation of or the factors underlying the psychoses but are even uncertain of any constant pathologic change characteristic of this state. In the present investigation an attempt has been made to attack this problem from a new angle.
It is suggested that much of the work on the psychoses has given negative results because the cerebral tissue was not obtained for examination during the life of the patient and because staining methods for oligodendroglia cells have only comparatively recently come to hand. These cells are so sensitive to change that they are rendered unfit for study during the agonal and the postmortem period that inevitably precedes necropsy.
Removal of cerebral tissue for biopsy, or Hirnpunktion, has been employed in Germany, especially in the differential diagnosis of dementia paralytica (Foerster1). However, the more recent silver impregnation methods are