CASTRATION OF CRYPTORCHIDS. 
129 
flabelliform, proceeds from the external anglq.of the ilium and 
the superior and external quarter of the crural arch. Its pos¬ 
terior border, slightly elevated, simply rests upon the crural 
arch, to which it is united by a loose connective tissue, except 
on a level with the inguinal ring, where the two organs are 
separated. At this point the small oblique is covered by the 
aponeurosis of the great oblique, which very thin and almost 
connective tissue twists by its archiform fibres around the 
posterior or external lip of the inguinal ring. 
The crural arch is a wide fibrous band, very strong and 
resisting, which, attached by one extremity to the external 
angle of the ilium, and by the other to the anterior border of 
the pubes, spreads itself upon the pelvi-crural muscles, and 
diminishing in structure, enters upward into the abdominal 
cavity. In the superior quarter of its length, it assists in the 
attachment of the small oblique muscle, and in the rest of its 
extent is simply resting on the posterior border of this mus¬ 
cle, thus co-operating in the formation of the inguinal canal and 
of the inguinal ring. 
{a) Inguinal Ring .—This is an oval opening easily felt 
under the skin, near the anterior border of the pubes, at the 
point of union of this border with the pre-pubic tendon of 
the abdominal muscles. Its great diameter is obliquely 
directed from before backward, and from without inward. 
Pierced through the aponeurosis of the great oblique of the 
abdomen, the inguinal ring, exposed by the incision of the 
scrotum, and of the dartos with the laceration of the connec¬ 
tive tissue underneath, presents two lips or borders, one an¬ 
terior or internal, the other posterior or external, and two 
commissures, one anterior and one posterior. 
The anterior or internal border is formed by the posterior 
border of the small oblique, upon which rest and adhere the 
fibres of the aponeurosis of the great oblique. This border 
is soft and inextensible, and though imperfectly defined by 
the touch, yet allows easily of a certain degree of dilitation 
of the inguinal ring. 
The posterior or external border, well stretched and re¬ 
sisting, is formed by the crural arch. It is straight, and by 
