Periodic changes in personality without amnesic dissociation are found in the region of _folie circulaire_, but are rarely seen in hysterics, as Renaudin's[66] case shows. A young man, whose behaviour had always been excellent, suddenly began to display the worst tendencies. There were no symptoms of insanity, but, on the other hand, the whole surface of the body was anæsthetic. This state showed periodic intervals, and in the same way the patient's character was subject to vacillations. As soon as the anæsthesia disappeared he was manageable and friendly. When the anæsthesia returned he was overcome by the worst instincts, which, it was observed, even included the wish to murder. Remembering that our patient's age at the beginning of the disturbances was 14 1/2, that is, the age of puberty had just been reached, one must suppose that there was some connection between the disturbances and the physiological character-changes at puberty. "There appears in the consciousness of the individual during this period of life a new group of sensations, together with the feelings and ideas arising therefrom; this continuous pressure of unaccustomed mental states makes itself constantly felt because the cause is always at work; the states are co-ordinated because they arise from one and the same source, and must little by little bring about deep-seated changes in the ego."[67] Vacillating moods are easily recognisable; the confused new, strong feelings, the inclination towards idealism, to exalted religiosity and mysticism, side by side with the falling back into childishness, all this gives to adolescence its prevailing character. At this epoch the human being first makes clumsy attempts at independence in every direction; for the first time uses for his own purposes all that family and school have contributed hitherto; he conceives ideals, constructs far-reaching plans for the future, lives in dreams whose content is ambitious and egotistic. This is all physiological. The puberty of a psychopathic is a crisis of more serious import. Not only do the psychophysical changes run a stormy course, but features of a hereditary degenerate character become fixed. In the child these do not appear at all, or but sporadically. For the explanation of our case we are bound to consider a specific disturbance of puberty. The reasons for this view will appear from a further study of the second personality. (For the sake of brevity we shall call the second personality IVENES--as the patient baptised her higher ego).