ABDOMINAL WALL 413 



extremity and lateral side of the posterior margin of the testis. 

 The superior extremity of the epididymis is enlarged, and is 

 termed the caput epididymidis (O.T. globus major] ; its inferior 

 extremity is called the cauda epididymidis (O.T. globus minor] ; 

 while the intervening portion,- which is narrow, receives the 

 name of the corpus epididymidis (body of the epididymis}. The 

 caput epididymidis is attached to the superior extremity of the 

 testis, which it surmounts like a helmet, both by the visceral 

 tunica vaginalis which is continued over it, and also by the 

 ductuli efferentes, which pass from the one into the other. 

 The cauda epididymidis is merely fixed to the back of the 

 testis by the visceral tunica vaginalis and some intervening 

 areolar tissue, whilst the body of the epididymis is free, and 

 is separated from the body of the testis by an involution of 

 the serous covering which forms the wall of the digital fossa, 



If the superior extremity of the body of the testis be care- 

 fully examined, two minute structures will be observed attached 

 to it close to the head. These are the appendices testis (O.T. 

 hydatids of Morgagni\ remnants of an embryonic canal called 

 Miiller's duct. One of the hydatids is usually pear-shaped 

 and stalked ; the other is smaller and generally sessile. 



The ductus deferens emerges from the inferior extremity of 

 the tail of the epididymis, and then passes upwards upon the 

 posterior margin of the testis and on the medial side of the 

 body and head of the epididymis. By this relation, the side 

 to which a given testis belongs can be readily detected. 

 The vessels have already been seen entering and emerging 

 from the posterior margin of the testis. 



Visceral Layer of the Tunica Vaginalis Testis. Having 

 learned the foregoing points concerning the testis, the 

 student is in a position to trace the visceral layer of the tunica 

 vaginalis. Observe that it is attached to the posterior border 

 of the testicle, where the vessels enter and emerge, and that 

 it covers the sides of the epididymis. On the lateral surface 

 of the organ it forms a little cul-de-sac between the body of 

 the epididymis and the body of the testis. This is called 

 the digital fossa. Note particularly that it is along the 

 posterior border of the testis that the epithelium lining 

 the tunica vaginalis becomes continuous with the epithelium 

 on the testis. 



Dissection. Some of the main facts relating to the structure of the 

 testis may be learned by a careful naked-eye examination of its different 



