The relation between the memory in dreams and in the hypnotic trance is curious: suggestions given in the trance may be accepted and then forgotten or never remembered in ordinary life; this does not prevent them from reappearing occasionally in dreams; conversely dreams forgotten in ordinary life may be remembered in the hypnotic trance. These dream memories of other states of consciousness suggest that dreams are sometimes the product of a deeper stratum of the personality than comes into play in ordinary waking life. It must be remembered in this connexion that we judge of our dream consciousness by our waking recollections, not directly, and our recollection of our dreams is extraordinarily fragmentary; we do not know how far our dream memory really extends. Connected with memory of other states is the question of memory in dreams of previous dream states; occasionally a separate chain of memory, analogous to a secondary personality, seems to be formed. We may be also conscious that we have been dreaming, and subsequently, without intermediate waking, relate as a dream the dream previously experienced. In spite of the irrationality of dreams in general, it by no means follows that the earlier and later portions of a dream do not cohere; we may interpolate an episode and again take up the first motive, exactly as happens in real life. The strength of the dream memory is shown by the recurrence of images in dreams; a picture, the page of a book, or other image may be reproduced before our eyes several times in the course of a dream without the slightest alteration, although the waking consciousness would be quite incapable of such a feat of visualizing. In this connexion may be mentioned the phenomenon of redreaming; the same dream may recur either on the same or on different nights; this seems to be in many cases pathological or due to drugs, but may also occur under normal conditions. _Personality._--As a rule the personality of the dreamer is unchanged; but it also happens that the confusion of identity observed with regard to other objects embraces the dreamer himself; he imagines himself to be some one else; he is alternately actor and observer; he may see himself playing a part or may divest himself of his body and wander incorporeally. Ordinary dreams, however, do not go beyond a splitting of personality; we hold conversations, and are intensely surprised at the utterances of a dream figure, which, however, is merely an _alter ego_. As in the case of Hilprecht (see above) the information given by another part of the personality may not only appear but actually be novel.