The epoch may be of a few hours, or it may be of days, of months, or years. The simplest example is the frequent amnesia for the few hours preceding a physical injury to the head resulting in temporary unconsciousness. In other cases it is the result of extensive dissociation effected by suggestion (e. g., in hypnosis), or psychical trauma including therein emotional conflicts. Thus, to cite an experimental example: Miss B. is troubled by a distressing memory which constantly recurs to her mind during the twenty-four hours. To relieve her I suggest that she will completely forget the original experience. To my surprise, though the suggestion is limited to the experience alone, the whole twenty-four hours are completely wiped out of her memory. She cannot recall a single incident of that day. The whole epoch which had associations with the memory is dissociated. When the epochal amnesia follows psychical trauma the condition of memory is apt to present the following peculiarity and the personality may be altered. When the epoch is the immediate past, i.e., includes the experiences extending from a certain past date up to the present, it sometimes happens that memory reverts to that past date. That is to say, the personality goes back to the period last remembered in which he believes, for the moment, he is still living, the memory of the succeeding last epoch being dissociated from the personal consciousness. Under such conditions there is something more than amnesia. The neurographic residua of the remembered epoch are revived and its experiences remembered as if they had just been lived. There is not only a dissociation of the memories of one epoch, but a resurrection of the conserved and maybe forgotten experiences of a preceding one. The synthesis of these memories restores again the personal consciousness of that period. Before the cleavage took place the recollection of the resurrected epoch may have been very incomplete and vague; afterward the new personality remembers it as if just experienced. The personality is, however, in other respects generally (always?) something different from the personality of that particular epoch. The dissociation is apt to involve a certain number of acquired traits and certain innate dispositions and instincts, while other outlived and repressed traits and innate dispositions and instincts are apt to be reawakened and synthesized into an altered abnormal personality. But this is another story that does not concern us now. As an example of epochal amnesia I may cite Mrs. J——, who, after dissociation occurs, has amnesia for all the events of several years succeeding a certain hour of a certain day when a psychical trauma (shock) occurred. She thinks she is living on that day and remembers in great detail its events as if they had just occurred.