ous ideas, and these latter, in their turn, further stimulate the
erection centre.

Normally, during coitus, erection is followed by _ejaculation_. A
special nerve centre for ejaculation is also supposed to exist; and the
ejaculation centre, like the erection centre, was formerly believed to
be situated in the lumbar enlargement of the spinal cord, but recent
investigations have shown that it also most probably forms part of the
sympathetic plexuses of the pelvis. This centre also may be stimulated
either by psychical or by physical stimuli. In normal conditions,
however, much more powerful stimuli are needed to cause ejaculation than
those which are competent to give rise to erection. For this reason,
erections often occur without leading to ejaculation, whereas in normal
conditions ejaculation hardly ever occurs without erection. In fact,
ejaculation in the absence of erection is almost peculiar to
pathological states, and may occur, for instance, in many forms of
impotence, in which the ejaculation centre still remains susceptible to
stimulation, whilst the erection centre is exhausted. Whereas
stimulation of the erection centre exercises its reflex influence
through the vasomotor nerves, thus leading to distension of the penis
with blood, the reflex impulses resulting from stimulation of the
ejaculation centre are transmitted by the motor nerves to certain
muscles--those, namely, whose contraction forcibly expels the
accumulated semen. The contractions of the affected muscles occur
rhythmically, the stimulation of the ejaculation centre giving rise to a
series of contractions alternating with relaxations. True ejaculation,
resulting from the activity of these muscles, must be distinguished from
the appearance of a drop or two of fluid at the urethral meatus, which
occasionally occurs at the outset of sexual excitement--the so-called
_urethrorrhoea ex libidine_. This fluid runs out while the ejaculatory
muscles are quiescent. It was formerly believed that it consisted of the
secretion of the prostate gland; but Fuerbringer, to whom we are indebted
for the most valuable researches in this province, has shown that this
view is erroneous. These drops are, he states, derived solely from the
glands of Littre and the glands of Cowper (urethral and suburethral
glands).

Sexual excitement is accompanied throughout by a sensation of pleasure,
specifically known as _voluptuous pleasure_, the _voluptuous sensation_,
or simply