Many fundamental questions concerning the cerebrospinal fluid, as, for example, whether it is wholly or only partially produced by filtration through the choroid plexus, remain unsolved. But the discoveries of modern workers, from Magendie through Cushing and his pupils, concerning the nature, origin, outlet and functions of the "third circulation," leave one free to enter on a discussion of the therapy in diseases affecting it, without first having to consider these other aspects.
In many papers on the treatment of hydrocephalus, the confidence of the authors in their own methods leads them to pass briefly over the efforts of others in the same direction. The present writer, from the beginning, must confess to a feeling of trepidation at offering still another method, and will at least review in some detail the multitudinous schemes presented—especially during the past forty years—for the cure of this distressing condition. Each one has its own