THE ABDOMINAL WALL 237 



with pins, and fill the tray with water. Divide the external 

 spermatic fascia longitudinally and turn it aside ; next make a 

 longitudinal incision through the cremasteric fascia along the 

 cord and reflect the divided fascia downwards over the testicle. 

 The cremasteric fascia consists of strands of muscle intermingled 

 with fibrous tissue. Then deal in a similar manner with the in- 

 ternal spermatic fascia, and, as the testicle is approached, be care- 

 ful not to injure the tunica vaginalis. After the internal spermatic 

 fascia has been reflected, dissect out the constituent parts of 

 the spermatic cord from the areolar tissue in which they are 

 embedded, and by which they are still surrounded. In the 

 anterior part of the cord lie the anterior veins of the pam- 

 piniform plexus and the internal spermatic artery. In the 

 posterior part are the posterior veins of the pampiniform plexus 

 and between the two groups of veins is the ductus deferens ac- 

 companied by its artery. 



Ductus Deferens (O.T. Vas Deferens). The ductus 

 deferens is the duct through which the spermatozoa pass 

 from the testicle to the urethra. It is, therefore, the most 

 important constituent of the cord. It can always be dis- 

 tinguished, both in the living and the dead body, by the 

 hard, firm, cord-like sensation which it gives when the 

 spermatic cord is held between the index finger and the 

 thumb. It commences at the lower end of the testicle, and 

 ascends, behind the testicle, to the spermatic cord. In the 

 cord it lies posteriorly, behind the internal spermatic artery 

 and the larger anterior group of veins of the pampiniform 

 plexus. At the subcutaneous inguinal ring it enters the 

 inguinal canal and passes through the canal, still accom- 

 panied by the veins and arteries. At the abdominal inguinal 

 ring it leaves the internal spermatic artery, and the internal 

 spermatic vein in which the pampiniform plexus has ended, 

 and, accompanied by the artery to the ductus deferens, it 

 hooks round the inferior epigastric artery and passes into 

 the pelvis. Its pelvic course is described on p. 451. 



The artery to the ductus deferens is a small branch from a 

 superior vesical. It passes along the duct to the testis. 



The external spermatic artery is a branch of the inferior 

 epigastric ; it has already been seen entering the cremaster 

 muscle. The external spermatic nerve, a branch of the genito- 

 femoral nerve, has a similar destination. It has been dis- 

 played in a previous stage of the dissection. 



The internal spermatic artery arises, within the abdomen, 

 from the front of the aorta ; it enters the cord at the ab- 

 dominal inguinal ring, and proceeds to the testis, into the 



