THE ABDOMINAL WALL 215 



It is important to mark exactly the relation which the 

 inferior part of the muscle bears to the spermatic cord. At 

 first the cord lies behind the fleshy fibres, but it soon emerges, 

 clothed by the cremaster muscle, and, as it is continued 

 downwards and medially to the subcutaneous inguinal ring, it 

 lies in front of the falx aponeurotica inguinalis (O.T. con- 

 joined tendon). Especially note the position of the falx 

 inguinalis in relation to the subcutaneous inguinal ring. 

 It lies immediately behind it, and gives strength to that 

 otherwise weak point in the abdominal parietes. 



M. Cremaster. The cremaster muscle supports the testis 

 and spermatic cord, and is consequently peculiar to the male. 

 It arises from the medial part of the inguinal ligament, and 

 it derives fibres also from the inferior border of the internal 

 oblique (rarely from the inferior border of the transversus 

 abdominis muscle). The fleshy fibres descend upon the lateral 

 and anterior aspects of the cord in the form of loops, the con- 

 cavities of which are directed upwards. The depth to which 

 the loops descend varies. Some reach the tunica vaginalis 

 of the testis, and the scrotum should now be opened up, on 

 the right side, in order that they may be traced downwards 

 to their terminations ; the majority of the fibres, however, do 

 not reach so far down, some going no farther than the sub- 

 cutaneous inguinal ring. Upon the posterior aspect of the 

 cord the loops are directed upwards, and some, reaching the 

 os pubis, obtain a tendinous insertion into its tubercle and 

 crest. 



It will be noticed that the cremasteric fleshy loops do not 

 form a complete investment for the cord and testis. The 

 intervals between the fasciculi are occupied by areolar tissue, 

 and the combination of muscular and areolar tissue is some- 

 times termed the cremasteric fascia. 



Dissection. Reflection of Internal Oblique. On the right 

 side of the body the entire muscle may be reflected, but on the 

 left side preserve the inferior portion of it (i.e., that part which 

 is still covered by the aponeurosis of the external oblique) in situ. 

 Begin below by dividing the muscular fibres along the crest of 

 the ilium. The depth to which the knife should be carried is 

 indicated by the dense areolar tissue which lies between the 

 internal oblique and the subjacent transversus muscle. An 

 ascending branch from the deep circumflex iliac artery will also 

 serve as a guide. That vessel emerges from the fibres of the 

 transversus muscle and then runs upwards upon its surface, 

 close to the anterior part of the iliac crest. Although the vessel 

 ii 14 c 



