more commonly in the
male, whilst the crural form, at the opening E, happens more frequently
in the female.

The most common forms of herniae happen at those localities where the
abdominal walls are traversed by the bloodvessels on their way to the
outstanding organs, and where, in consequence, the walls of the abdomen
have become weakened. It also happens, that at these very situations the
visceral pressure is greatest whilst the body stands erect. These
localities are, A, the umbilicus, a point characterized as having given
passage (in the foetal state) to the umbilical vessels; D, the place
where the spermatic vessels and duct pass from the abdomen to the
testicle; and immediately beneath this, the crural arch, which gives
exit to the crural vessels. Herniae may happen at other localities, such
as at the thyroid aperture, which transmits the thyroid vessels; and at
the greater sacrosciatic notch, through which the gluteal vessels pass;
and all regions of the abdominal walls may give exit to intestinal
protrusion in consequence of malformations, disease, or injury. But as
the more frequent varieties of herniae are those which traverse the
localities, A, D, E, and as these, fortunately, are the most manageable
under the care of the surgical anatomist, we proceed to examine the
structures concerned in their occurrence.

A direct opening from within outwards does not exist in the walls of the
abdomen; and anatomy demonstrates to us the fact, that where the
spermatic cord, D F, and the femoral vessels, pass from the abdomen to
the external parts, they carry with them a covering of the several
layers of structures, both muscular and membranous, which they encounter
in their passage. The inguinal and crural forms of herniae which follow
the passages made by the spermatic cord, and the crural vessels, must
necessarily carry with them the like investments, and these are what
constitute the coverings of the herniae themselves.

The groin in its undissected state is marked by certain elevations and
depressions which indicate the general relations of the subcutaneous
parts. The abdomen is separated from the thigh by an undulating grooved
line, extending from C*, the point of the iliac bone, to B, the
symphysis pubis This line or fold of the groin coincides exactly with
the situation of that fibrous band of the external oblique muscle named
Poupart's ligament. From below the middle of this abdomino-femoral
groove, C B, another