914 A MANUAL OF ANATOMY 



dissector of the lower limb ; and (2) at the internal ring it is carried downwards 

 with the spermatic cord. 



The parietal peritoneum is now to be examined. It will be readily recog- 

 nised by its bluish-white colour, and upon it a small nodule is to be looked 

 for just behind the internal abdominal ring, representing the upper end of the 

 original processus vaginalis. Instead of a mere nodule the dissector may 

 find a fibrous thread descending for a variable distance on the spermatic cord, 

 and sometimes containing a canal in the female, known as the canal of Nuck. 

 The disposition of the fascia transversalis and fascia iliaca along the outer 

 half of Poupart's ligament, and in the region of the external iliac vessels 

 at the groin is to be attended to, the deep crural arch being at the same time 

 revised. Gimbernat's ligament may be looked to at this stage, but its com- 

 plete examination should be postponed till a later period. 



The abdominal cavity is now to be opened. This is to be done only partially 

 at first by means of the following incisions : commencing immediately below 

 the umbilicus, an incision is to be made downwards and outwards, on either 

 side, to Poupart's ligament at the junction of its inner two-thirds and outer 

 third. In this manner a triangular portion of the anterior abdominal wall 

 below the umbilicus can be thrown down. The parietal peritoneum lining 

 this portion having been sponged, the following plica; and fossa; are to be 

 studied : (i) Folds. — (a) plica urachi, in the middle line ; (b) plica hypogas- 

 trica ; and (c) plica epigastrica, which is usually a little external to the plica 

 hypogastrica, though sometimes the two correspond. (2) Fossae. — These 

 are the internal, middle, and external inguinal fossae. The relations of the 

 internal and middle fossae to the two divisions of Hesselbach's triangle are 

 to be noted, as well as the relation of the external fossa to the internal abdo- 

 minal ring. At this stage the dissector should study the descent of the testis, 

 and the abnormal conditions of the processus vaginalis. A complete revisal 

 of all the structures of the abdominal wall in the region of Poupart's ligament 

 should now be made, and thereafter inguinal hernia is to receive careful 

 attention in the following order : external oblique hernia ; internal direct 

 hernia ; internal oblique hernia ; congenital hernia ; and infantile hernia. 

 Having mastered these varieties of hernia, the dissector should now turn his 

 attention to umbilical hernia, or exomphalos. The relation of structures 

 at the pubic crest is next to be mastered, as well as the relation of parts at 

 the pectineal portion of the ilio-pectineal line. 



It will be proper to dissect the testis at this stage, if it is in proper con- 

 dition. If not, it should be delayed until the organ has been sufficiently 

 hardened by immersion in spirit. The testis, along with the lower part 

 of the spermatic cord, is to be removed and laid upon a board, and the parts 

 are to be kept in position by pins. The tunica vaginalis is to be studied, and 

 the dissector should note that the lower fibres of the cremaster spread out in 

 a scattered manner over its upper part. An attempt should be made to 

 inflate it, by making an aperture in it, just large enough to admit the small 

 end of a blow-pipe. If this is successfully done, an instructive view of the 

 membrane will be obtained. The tunica vaginalis is then to be divided by 

 a vertical incision, when its two parts will come readily into view, namel5^ 

 tunica vaginalis scroti and tunica vaginalis testis. These two parts having 

 been studied, attention is next to be directed to the following structures : 

 ( I ) the body of the testis, closely invested by the dense tunica albuginea, which, 

 in turn, is closely covered by the tunica vaginalis testis ; (2) the epididymis, 

 which will be seen lying along the posterior border and adjacent portion of 

 the external surface of the testis ; and (3) the digital fossa, which is a recess 

 formed by the tunica vaginalis testis between the testis and the epididymis. 

 The epididymis will be seen to be composed of a head or globus major, situ- 

 ated at the upper end ; a body, succeeding to the head, long and narrow : 

 and a tail or globus minor, situated at the lower end of the body. Before 

 proceeding further, the dissector should look carefully for the following 

 vestiges of embryonic structures, namely (i) the hydatids of Morgagni, 

 which will usually be seen on the front of the globus major, or on the front of 

 the testis just below the globus major ; (2) the organ of Giraldes or para- 



