4. Sleep walking can also have an infantile prototype, when the child pretends to be asleep in order that it may be able, without fear of punishment, to experience all sorts of forbidden things, that is of a sexual nature, because it cannot be held accountable for that which it does "unconsciously, in its sleep." The same motive of not being held accountable actuates the adult sleep walker, who will satisfy his sexual desires, yet without incurring guilt in so doing. The same cause works also psychically, when sleep walking occurs mostly in the very deepest sleep, even if organic causes are likewise responsible for it. 5. The motor outbreak during sleep, which drives one from rest in bed and results in sleep walking and wandering under the light of the moon, may be referred to this, that all sleep walkers exhibit a heightened muscular irritability and muscle erotic, the endogenous excitement of which can compensate for the giving up of the rest in bed. In accordance with this these phenomena are especially frequent in the offspring of alcoholics, epileptics, sadists and hysterics with preponderating involvement of the motor apparatus. 6. Sleep walking and moon walking are in themselves as little symptoms of hysteria as of epilepsy. Yet they are found frequently in conjunction with the former. 7. The influence of the moon in this moon affectivity is very little known, especially in its psychic overdetermination. Yet there is little doubt that the moon's light is reminiscent of the light in the hand of a beloved parent, who every night came in loving solicitude to assure himself or herself of the child's sleep. Nothing so promptly wakes the sleep walker as the calling of his name, which accords with his being spoken to as a child by the parent. Fixed gazing upon the planet also has probably an erotic coloring like the staring of the hypnotizer to secure hypnosis. Other psychic overdeterminations appear merely to fit individual cases. It is possible finally that there actually exists a special power of attraction in the moon, which may expressly force the moon walker out of his bed and entice him to longer walks, but on this point we have no scientific hypotheses. 8. Furthermore it seems possible that sleep walking and moon walking may be permanently cured through Freud's psychoanalytic method. I know very well that this explanation which I give here, offers only the first beginning of an understanding. It will be the task of a future, which we hope is not too far distant, to comprehend fully these puzzling phenomena. INDEX "Aebelö," ix, 45 Alcoholics, 137 descendants of, 25 Alcoholism, 1 Anorexia, hysteric, 76 Anxiety dreams, 41 Anzengruber, Ludwig, ix, 106 Audition, color, 91 Blood, 3, 15, 17, 20 Burdach, Karl Friedrich, 35 "Buschnovelle," 91 Buttocks, 7 moon as, 19 Cataleptic muscular rigidity, 25 Color audition, 74, 91 Compulsion, 6 Compulsive neurotic, 77, 91