theologians, needless to say, were opposed to the _mos
diabolicus_, and already in the Anglo-Saxon Penitential of
Theodore, at the end of the seventh century, 40 days' penance is
prescribed for this method of coitus.

From the frequency with which they have been adopted by various
peoples as national customs, most of the postures in coitus here
referred to must be said to come within the normal range of
variation. It is a mistake to regard them as vicious perversions.

Up to the point to which we have so far considered it, the process of
detumescence has been mainly nervous and vascular in character; it has, in
fact, been but the more acute stage of a process which has been going on
throughout tumescence. But now we reach the point at which a new element
comes in: muscular action. With the onset of muscular action, which is
mainly involuntary, even when it affects the voluntary muscles,
detumescence proper begins to take place. Henceforward purposeful psychic
action, except by an effort, is virtually abolished. The individual, as a
separate person, tends to disappear. He has become one with another
person, as nearly one as the conditions of existence ever permit; he and
she are now merely an instrument in the hands of a higher power--by
whatever name we may choose to call that Power--which is using them for an
end not themselves.

The decisive moment in the production of the instinctive and involuntary
orgasm occurs when, under the influence of the stimulus applied to the
penis by friction with the vagina, the tension of the seminal fluid poured
into the urethra arouses the ejaculatory center in the spinal cord and the
bulbo-cavernosus muscle surrounding the urethra responsively contracts in
rhythmic spasms. Then it is that ejaculation occurs.[106]

"The circulation quickens, the arteries beat strongly," wrote Roubaud in a
description of the physical state during coitus which may almost be termed
classic; "the venous blood, arrested by muscular contraction, increases
the general heat, and this stagnation, more pronounced in the brain by the
contraction of the muscles of the neck and the throwing of the head
backward, causes a momentary cerebral congestion, during which
intelligence is lost and the faculties abolished. The eyes, violently
injected, become haggard, and the look uncertain, or, in the majority of
cases, the eyes are closed spasmodically to avoid the contact of the
light. Th