Studied certain types of hysteria from the point of view of the dissociated personality; and conversely, the dissociated personality from the point of view of hysteria. The method used was entirely clinical. 20 cases were selected for observation, to recognize the essential clinical characteristics manifested by them. They led to the following conclusions: (1) the individual, physiological and mental alterations observed were not peculiar to this condition, (2) amnesia was not an essential characteristic of secondary personalities, and (3) hysteria may alternate with other symptom-complexes, such that amnesia is exhibited. Concludes that certain symptom-complexes commonly placed under the name of hysteria with or without amnesia, are to be regarded as disintegrated or secondary personality, which when taken in connection with the normal condition, are to be regarded as a phase of multiple personality. (PsycINFO Database Record (c) 2006 APA, all rights reserved)