278 SURGICAL APPLIED ANATOMY. [Chap. xvi. 



cases the abdominal walls are fairly complete, but 

 there is a lack of union in the middle line about the 

 umbilicus. Thus result the various forms of con- 

 genital exomphalos, which may vary in severity from 

 a small hernia to a protrusion of the whole of the 

 more moveable viscera. One of the most remarkable 

 deformities is that known as extroversion of the 

 bladder. Here, not only is a part of the belly wal] 

 absent, but also a part of the geni to-urinary apparatus. 

 In complete cases there is an absence of the umbilicus 

 and of the anterior abdominal wall below it. There is 

 no symphysis pubis, an absence of the anterior 

 wall of the bladder, of the principal part of the penis, 

 and the whole of the roof of the urethra. The 

 scrotum, also, as may be expected from a reference to 

 the development of that part, is bifid. 



Hernia,. 1. Inguinal hernia. In this form of 

 rupture the herniated bowel occupies the inguinal 

 canal for the whole or part of its entire length. This 

 canal runs obliquely from the internal to the external 

 abdominal ring, and is about one and a half inches in 

 length. It represents the track followed by the testis 

 in its descent. It is, in a sense, a passage right through 

 the abdominal walls, and is occupied by the spermatic 

 cord. It is not a free canal, however, in the same 

 sense as one would speak of an open tube, but is rather 

 a potential one, a tract of tissue so arranged as to 

 permit of a body being thrust along it. It is a breach 

 in the abdominal wall, not a doorway ; a breach 

 that is forcibly opened up and widened in the acquired 

 forms of hernia. When a hernia occupies the in- 

 guinal canal it is covered in front by the integuments, 

 the external oblique aponeurosis, and the lower fibres 

 of the internal oblique and transversalis muscles. It 

 rests behind upon the transversalis fascia, the 

 conjoined tendon, and the triangular ligament ; over 

 it arches the transverse and internal oblique 



