Sex efficiency through exercises : special physical culture for women / by Th. H. van de Velde ; [photos, by E. Steinemann].

The superficial muscular layer, which is limited to the anterior portion of the pelvic outlet—as depicted on Plate I. —also consists of a kind of sphincter or locking apparatus in its most important region. But the structure here is somewhat more complex and less obvious than in the sphincter ani. The muscular fibres of the anterior, pelvic floor do not, as a rule, enclose the vaginal orifice ; some of them cross over and unite with the fibres of the sphincter ani, while others again merge with the tense and massive sinews of the perineum. Nevertheless, though anatomically dispersed, they are a functional unit, and serve to close the orifice of the vagina ; that is, they are a constrictor muscle. This Constrictor Cunni—as already mentioned in my treatise on " Ideal Marriage "—is not nearly so tensely resistant as the Anal Constrictor, but is, nevertheless, quite sufficiently powerful—congenitally in many women and, as a result of appropriate and deliberate physical exercise in others—to play an effective role in coitus, both in accen- tuating the natural pleasure of both partners, and in retain- ing the seminal fluid and thus helping impregnation. The underlying and more powerful muscular stratum (the group of the levatores, see Plate II.) has a somewhat conical shape. At its lowest point, it is intersected by the rectum. The focus of this muscular cone, far from being circular, is rather an oval slit, whose front rim is formed by the bony symphysis pubis, while the rear rim encircles the rectum slightly above the sphincter ani and from behind. Let us suppose that this cone or funnel-shaped muscular stratum is contracted by voluntary action : then the two passages—rectal and vaginal—which intersect it will obviously be affected. The most obvious effect of the initial contraction will be to draw the lower extremity of the rectum upward and forward. Therefore, the name " Levator Ani "—" Lifter of the Anus "—has been given to this whole muscular stratum. The rectum is not only lifted forward, but narrowed from behind and from either side, in such a manner that the sphincter ani is helped in its function. (This may be observed—as it is employed—by any person wishing to control and retain an attack of diarrhoea.)