WALL OF THE ABDOMEN. 261 



the male, the prominence of the spermatic cord descending through 



it to the testicle. The internal abdominal ring is farther out than and inner. 



the external, and cannot be recognised on the surface with the 



finger ; its position may be ascertained by taking a point midway 



between the symphysis pubis and the anterior superior iliac spine, 



and a finger's breadth above Poupart's ligament. 



Dissection. The requisite incisions for raising the skin from the Raise the 

 sides and front of the belly are the following : One cut is to extend the^ron 

 outwards over the side of the chest from the ensiform process to 

 about midway between the sternum and the spine (fig. 1, B. 7 , 

 p. 3). A second incision begins at the symphysis pubis, and is 

 carried outwards along Poupart's ligament and the iliac crest till it 

 emls opposite the first cut (8). Lastly, the anterior extremities of 

 the two incisions are to be connected along the middle line of the 

 belly (3). The piece of skin thus marked out is to be raised out- 

 wards, but is not to be taken away ; and the cutaneous vessels and 

 nerves are to be sought in the fat at the side and front of the 

 abdomen. 



Along the side of the abdomen look for the lateral cutaneous Position of 

 nerves (fig. 97, p. 263), five or six in number, which issue in a line nervesT* 8 

 with the corresponding nerves of the thorax. At first they lie 

 beneath the fat, and divide into two ; one offset is to be traced 

 forwards and the other backwards, with small cutaneous arteries. 

 On the iliac crest, near the front, is a large branch from the last on the side 

 dorsal nerve ; and usually farther back on the crest, and deeper, is a 

 smaller branch of the ilio-hypogastric nerve. Near the middle line and in front, 

 the small anterior cutaneous nerves will be recognised with com- 

 panion arteries : they are uncertain in number and size, and are 

 to be followed outwards in the fat. 



In the inguinal region the cutaneous vessels and nerves are to be Seek vessels 

 dissected on the right side, and the superficial fascia on the left. 

 For this purpose, all the fascia superficial to the vessels is to be 

 removed from the right groin. The vessels which will then appear 

 are the superficial external pudic internally, the superficial epigastric 

 in the centre, and an offset of the superficial circumflex iliac artery 

 externally. Some inguinal glands lie along the line of Poupart's 

 ligament. Two cutaneous nerves are to be sought : one, the ilio- and nerves 

 inguinal, comes through the external abdominal ring, and descends 

 to the thigh and scrotum (fig. 97, I i) ; the other, ilio-hypogastric, 

 appears in the superficial fascia above, and rather outside the 

 abdominal ring (I-H). 



In the examination of the superficial fascia on the left side two Separate 

 strata are to be made out, one over and one beneath the vessels. 

 The layer that is superficial to the vessels is to be reflected by means 1 

 of a transverse cut directed inwards from the front of the iliac crest, 

 and by a vertical one near the middle line to the pubic bone. The 

 subjacent vessels mark the depth of this layer; and when these 

 are reached, a triangular flap of the fascia is to be thro\vn towards 

 the thigh. To define the thinner deep stratum, cut it across in the 



