414 ABDOMEN 



parts. For this purpose place it in a cork-lined tray and dissect it under 

 water. Having fixed it to the bottom of the tray, with pins, begin by 

 tracing the vessels into the gland. In doing this a quantity of involuntary 

 muscular tissue spread over the posterior border of the testis and the 

 epididymis becomes apparent. This is the inner muscular tunic of Kolliker. 

 Now free the tail and body of thj epididymis from the back of the 

 gland. This can be easily done by cutting the serous covering as it passes 

 from one to the other, and breaking through the fibrous tissue which 

 intervenes between the tail and the lower part of the body of the 

 testis. Do not interfere with the head. When the body and tail of the 

 epididymis are turned aside, the body of the testis may be divided trans- 

 versely, with a sharp knife, about its middle, into an upper and a lower 

 portion. 



Structure of the Testis. The cut surface of the lower 

 part of the body of the testis may now be studied. The 

 dense, tough fibrous coat which envelops it, under cover of 

 the epithelium, first attracts attention. It is called the 

 tunica albuginea. At the posterior margin of the testis it 

 will be seen to be projected into the interior in the form 

 of a thick fibrous elevation. This extends along the whole 

 length of the posterior border, and receives the name of 

 the mediastinum testis (corpus Highmori). It is traversed 

 by the vessels that pass into and out from the gland, and 

 it is also tunnelled by a plexus of seminal canals, called the 

 rete testis (Hallerf). 



From the front and sides of the mediastinum testis radiat- 

 ing fibrous lines will be seen passing into the substance of 

 the testis. These are the cut margins of incomplete fibrous 

 septula which extend towards the deep surface of the tunica 

 albuginea and become connected with it (Fig. 154). By 

 means of these partitions and the mediastinum testis, the 

 space enclosed by the tunica albuginea becomes broken up 

 into a large number of lobules or compartments, two to three 

 hundred in number, the walls of which are imperfect. Such 

 is the fibrous framework of the body of the testicle. 



The blood-vessels have a very definite arrangement with 

 reference to this framework. Passing in through the media- 

 stinum they spread out on the deep surface of the tunica 

 albuginea, and upon both surfaces of the fibrous septula 

 which bound the testicular compartments. The vascular 

 mesh -work thus formed is sometimes called the tunica 

 vasculosa. 



The proper glandular substance of the testis is lodged 

 within the compartments described above. It consists of an 

 enormous number of fine hair-like tubes, termed the contorted 



