Besides there is absolute amnesia succeeding this. Upon persistent questioning there is an attempt to fill in the gaps in memory by confabulation, like the effort to explain posthypnotic action. Furthermore, it is asserted that a specially deep sleep always ushers in night wandering, that indeed the latter in general is only possible in this condition. It is more frequent with children up to puberty and throughout that period than with adults. At the same time the first outbreak of sleep walking occurs often at the first appearance of sexual maturity. According to a widespread folk belief sleep walking will cease in a girl when she becomes pregnant with her first child. It seems to me that practically no scientific treatment of this problem exists. Modern psychiatry, so far as it takes a sort of general notice of it, contents itself, as Krafft-Ebing does, with calling night wandering "a nervous disease," "apparently a symptomatic manifestation of other neuroses, epilepsy, hysteria, status nervosus."[2] The older literature is more explicit. It produces not only a full casuistic but seeks to give some explanation aside from a reference to neurology.[3] So, for example, the safety in climbing upon dangerous places finds this explanation, that the sleep walker goes there with closed eyes and in this way does not see the danger, knows no giddiness and above all is in possession of a specially keen muscular sense. [2] Lehrbuch der gerichtlichen Psychopathologie. [3] I introduce as the most important sources Peter Jessen: "Versuch einer wissenschaftlichen Begründung der Psychologie," Berlin, 1855 (with many examples); Heinrich Spitta: "Die Schlaf- und Traumzustände der menschlichen Seele," 2d edition, 1882 (with abundant casuistic and literature); finally based upon these L. Löwenfeld: "Somnambulismus und Spiritismus," Grenzfragen des Nerven- und Seelenlebens, Vol. I, 1900.