The Nature of the Cerebrospinal Fluid

The cerebrospinal fluid, noted by Galen, Vesalius and Valsalva, received its first important description from François Magendie,1in 1825. His monograph,2published in 1842, marked the beginning of numerous investigations stimulated by the increasing diagnostic and therapeutic importance of this fluid and its intimate relation to the problem of intracranial pressure. Faivre,3in 1854, suggested that the choroid plexus was the source of the fluid, a view that has been accepted by most of the important investigators in this field; but it was not until 1919 that conclusive evidence was available. In that year, Dandy4demonstrated that obstruction of the foramen of Monro resulted in dilatation of the obstructed ventricle, but that such hydrocephalus never occurred if the choroid plexus of the same ventricle was removed. Hassin,5however, seriously opposes the view that the choroid plexus is a source of cerebrospinal fluid. He believes that