DISSECTION OP THE PERINEUM IN THE MALE. 279 



its serous covering. It passes upwards through the inguinal canal, in 

 which its connections will be observed at a later stage. 



The Spermatic Vessels. The spermatic artery is an important vessel 

 from the hsemorrhage to which it may give rise in castration. It is 

 placed in the anterior part of the cord, and in a well-injected subject its 

 remarkably convoluted disposition will be evident without dissection. 

 The spermatic veins accompany the artery. They are large and tor- 

 tuous. 



The Vas Deferens is the excretory duct of the testicle, and is placed 

 at the posterior part of the spermatic cord, where it may be seen and 

 felt as a thick, firm tube. 



Directions. — The student, having identified these different elements of 

 the cord, may practise the operation of castration by any one of the 

 common methods, taking care to sever the spermatic cord just above the 

 epididymis, at the upper border of the testicle. The cord is to be left 

 in the inguinal canal. 



the testicle and EPIDIDYMIS (PLATES 46 AND 47). 



The Testicle is the gland that secretes the semen — the male fertil- 

 izing fluid. In form it is ovoid. Its faces, right and left, are smooth 

 and rounded; its inferior border is slightly convex and free; its upper 

 edge is nearly straight, and is related to the epididymis. Its anterior 

 extremity shows below the globus major of the epididymis a small cyst- 

 like body — the peduncidated hydatid of Morgagni. 



The Epididymis is made up of the convolutions of the excretory tube 

 of the testicle. It presents anteriorly an enlargement termed the 

 glohtis major, and posteriorly a lesser enlargement termed the globus 

 m,inor, the intermediate part being called the body. At the globus 

 minor the tube loses its convoluted disposition, and is continued as the 

 vas deferens, which, as already seen, becomes one of the constituents of 

 the spermatic cord. 



Structure. The testicle has for its most external investment the 

 tunica vaginalis j)7'op7na. This, as already explained, is a serous mem- 

 brane which passes on to the testicle from the cord, and is continuous 

 with the peritoneum at the upper opening of the inguinal canal. It is, 

 as it were, the visceral part of a serous membrane, the ttmica vaginalis 

 rejiexa — the inner lining of the bag in which the testicle lies free — 

 being the parietal portion of the same membrane. This covering is 

 thin and transparent, and closely adherent to the next covering — the 

 tunica alhuginea. The tunica albuginea is a complete envelope of dense, 

 lamellated connective-tissue, containing some fibres of non-sti-iped 

 muscular tissue. Towards the upper and anterior part of the testicle, a 

 strong process from the tunica albuginea passes into the interior of the 

 gland. This is tenned the corpus Highmori, or mediastinum testis; and 



