een subject to monthly attacks of
sexual excitement, after the age of 45 completely lost the liability to
these manifestations, but found himself subject, in place of them, to
monthly attacks of frequent and copious urination, accompanied by sexual
day-dreams, but by no genital excitement.[56] Such a case admirably
illustrates the compensatory relation of sexual and vesical excitation.
This mutual interaction is easily comprehensible when we recall the very
close nervous connection which exists between the mechanisms of the sexual
organs and the bladder.

Nor are such relationships found to be confined to these two centers; in a
lesser degree the more remote explosive centers are also affected; all
motor influences may spread to related muscles; the convulsion of
laughter, for instance, seems to be often in relation with the sexual
center, and Groos has suggested that the laughter which, especially in the
sexually minded, often follows allusions to the genital sphere is merely
an effort to dispel nascent sexual excitement by liberating an explosion
of nervous energy in another direction.[57] Nervous discharges tend to
spread, or to act vicariously, because the motor centers are more or less
connected.[58] Of all the physiological motor explosions, the sexual
orgasm, or detumescence, is the most massive, powerful, and overwhelming.
So volcanic is it that to the ancient Greek philosophers it seemed to be a
minor kind of epilepsy. The relief of detumescence is not merely the
relief of an evacuation; it is the discharge, by the most powerful
apparatus for nervous explosion in the body, of the energy accumulated and
stored up in the slow process of tumescence, and that discharge
reverberates through all the nervous centers in the organism.

"The sophist of Abdera said that coitus is a slight fit of
epilepsy, judging it to be an incurable disease." (Clement of
Alexandria, _Paedagogus_, bk. ii, chapter x.) And Coelius
Aurelianus, one of the chief physicians of antiquity, said that
"coitus is a brief epilepsy." Fere has pointed out that both
these forms of nervous storm are sometimes accompanied by similar
phenomena, by subjective sensations of sight or smell, for
example; and that the two kinds of discharge may even be
combined. (Fere, _Les Epileptiques_, pp. 283-84; also "Exces
Veneriens et Epilepsie," _Comptes-rendus de la Societe de
Biologie_, April 3, 1897, and the same author's