Moll's comparison of nocturnal emissions of semen with nocturnal incontinence of urine suggests an interesting resemblance, and at the same time seeming contrast. In both cases we are concerned with viscera which, when overfilled or unduly irritable, spasmodically eject their contents during sleep. There is a further resemblance which usually becomes clear when, as occasionally happens, nocturnal incontinence of urine persists on to late childhood or adolescence: both phenomena are frequently accompanied by vivid dreams of appropriate character. (See e.g. Ries, "Ueber Enuresis Nocturna," _Monatsschrift für Harnkrankheiten und Sexuelle Hygiene_, 1904; A.P. Buchan, nearly a century ago, pointed out the psychic element in the experiences of young persons who wetted the bed, _Venus sine Concubitu_, 1816, p. 47.) Thus, in one case known to me, a child of seven, who occasionally wetted the bed, usually dreamed at the same time that she wanted to make water, and was out of doors, running to find a suitable spot, which she at last found, and, on awaking, discovered that she had wetted the bed; fifteen years later she still sometimes had similar dreams, which caused her much alarm until, when thoroughly awake, she realized that no accident had happened; these later dreams were not the result of any actual strong desire to urinate. In another case with which I am acquainted, a little girl of eight, after mental excitement or indigestible meals, occasionally wetted the bed, dreaming that she was frightened by some one running after her, and wetted herself in consequence, after the manner of the Ganymede in the eagle's clutch, as depicted by Rembrandt. These two cases, it may be noted, belong to two quite different types. In the first case, the full bladder suggests to imagination the appropriate actions for relief, and the bladder actually accepts the imaginative solution offered; it is, according to Fiorani's phrase, "somnambulism of the bladder." In the other case, there is no such somnambulism, but a psychic and nervous disturbance, not arising in the bladder at all, irradiates convulsively, and whether or not the bladder is overfull, attacks a vesical nervous system which is not yet sufficiently well-balanced to withstand the inflow of excitement. In children of somewhat nervous temperament, manifestations of this kind may occur as an occasional accident, up to about the age of seven or eight; and thereafter, the nervous control of the bladder having become firmly established, they cease to happen, the nervous energy required to affect the bladder sufficing to awake the dreamer. In very rare cases, however, the phenomenon may still occasionally happen, even in adolescence or later, in individuals who are otherwise quite free from it. This is most apt to occur in young