The preface of this monograph on hallucinations was written by J. Seglas, the eminent psychiatrist of the Salpetriere, who duly emphasizes that in spite of the large number of works for which this subject has furnished the material, the principal issues are still highly problematic. He points out that anatomo-physiologic theories one after another have all but failed, but that the same is not entirely true of the psychologic theories, many of which have greatly advanced our knowledge of hallucinatory phenomena, however, without always being able to offer definite explanations. In the past it would seem that more attention has been given to attempts to study and explain hallucinations of a toxic origin and of a visual character than those of auditory significance. The verbal character of the hallucination must be recognized, and when this is done the subject becomes a chapter in the pathology of “interior language” rather