contents of the vesicles into the urethra at the same
moment when the epididymis the vas deferens and the ducts of the
prostate are emptying their secreted contents into the urethra.

Now the sensory nerves passing from the seminal vesicles up to the
erection and emission centers are stimulated by any unusual pressure
within the vesicles. Unusual pressure may be caused either by
distention due to accumulated secretion or by pressure upon the
vesicles from over-distended rectum or bladder. It sometimes happens
that two or more of these influences are acting at the same time.
These impulses are most likely to be effective when the subject is
asleep, and particularly if he is lying upon his back. The result of
the stimulus is to cause an erection, accompanied usually by an erotic
dream, the whole phenomenon culminating in an emission of the contents
of the seminal vesicles and followed, of course, by a relief of the
pressure which was the cause of the condition. This phenomenon has
been variously called _nocturnal emission_, "pollution" and
"dreaming-off."

Vecki, a specialist in physiology, hygiene and pathology of the sexual
apparatus, says that the nocturnal emission is a normal physiological
phenomenon, the object of which is to relieve pressure in the seminal
vesicles, and that in normal cases it occurs in fairly regular
periods, these periods varying in length with different individuals,
according to their physical condition and habits, the period being two
to four weeks, usually; though a considerably longer or shorter
period would not be looked upon as pathological. Vecki describes the
normal nocturnal emission as being accompanied by an erection, erotic
dreams, and an orgasm, the subject being wholly unconscious of the
condition until he is awakened at the moment of orgasm. Normally, the
subject experiences on the following day a feeling of relief and
well-being and should, normally, be wholly free from headache,
depression or languor.

Inquiry among a large number of normal healthy men convinces the
author that it is not at all unusual for these emissions to occur as
infrequently as once in two months in normal healthy men. On the other
hand, it is not unusual for them to occur as frequently as once in ten
days or even once a week and still be within the physiological limit.
However, when the emission occurs as frequently as once per week, it
should be looked upon as abnormal if it is followed by depression,