444 THE TESTICLES AND ACCESSORY STRUCTURES. 



membranes in c"eneral, of which it presents one of the simplest forms, 

 it may be described as consisting of a viscer al and a parietal portion. 

 The visceral portion, iunica vaginalis testis, closely invests the greater 

 part of the body of the testis, as vt^ell as the epididymis, between which 

 parts it is depressed in the form of a pouch (digital fossa), and lines 

 their contiguous surfaces, and it adheres intima tely to the proper fibrous 

 tunic of the gland. Along the posterior border of the gland,' where the 

 vessels and ducts enter or pass out, the serous coat, having been re- 

 flected, is wanting. This portion of the serous covering frequently pre- 

 sents villous prolongations on the borders of the epididymis and upper 

 end of the testis ; these processes, sometimes of __co nsiderable length, are 

 covered in some places with cylindrical, in otfiers with layers of flat 

 epithelium (Luschka, in Virchow's Archiv, Vol. VI., p. 321, and La 

 Valette St. George, in Strieker's Handbuch, p. 523). 



The parietal or scrotal portion of the tunica vag inalis is more exten- 

 sive than that which covers the body of the testis ; it reaches upwards, 

 sometimes for a considerable distance, upon the spermatic cord, extend- 

 ing somewhat higher on the inner than on the outer side. It also 

 reaches downwards below the testicle, which, therefore, appears to be 

 suspended at the back of the serous sac, when this latter is distended 

 with fluid ; a fold, or so-called ligament, being left projecting at the 

 lower end of the epididymis. 



Vessels and nerves of the scrotum and spermatic cord. 

 — The arteries are derived from several sources. Thus, the two ex- 

 ternal pudic arteries, branches of the femoral, reach the front and sides 

 of the scrotum, supplying the integument and dartos ; the superficial 

 perineal branch of the internal pudic artery is distrib uted to the back 

 part of the scrotum ; and, lastly, more deeply seated than either of these 

 is a branch given from the epigastric artery, named cremasteric, which 

 is chiefly distributed to the cremaster muscle, but also supplies small 

 branches to the other coverings of the cord, and by its ultim.ate divisions 

 anastomoses with the other vessels. The artery of the vas deferens, a 

 long slender vessel derived from the superior vesical, accompanies the 

 tube in its whole length. The veins, which, from the thinness of the 

 integuments, are apparent on the surface of the scrotum, follow the 

 course of the arteries. The veins of the cord form the spermatic or 

 pampiniform plexus elsewhere described. The tympliatics pass into the 

 inguinal lymphatic glands. 



The nerves also proceed fi'om various sources. Thus, the ilio- 

 inguinal, a branch of the lumbar plexus issuing by the external abdo- 

 minal ring, supplies the integuments of the scrotum ; this nerve is 

 joined also by a filament from the ilio-hypogastric branch of the same 

 plexus : sometimes two separate cutaneous nerves come forward through 

 the external ring. The two superficial perineal branches of the internal 

 pudic nerve accompany the artery of the s ame name and supply the 

 inferior and posterior parts of the scrotum. The inferior pudendal, a 

 branch of the small sciatic nerve, joins vdth the perineal nerves, and 

 with them is distributed to the sides and fore part of the scrotum. 

 Lastly, the spermatic branch of the genito -crural nerve reaching the 

 spermatic cord at the internal abdominal ring, passes with it through 

 the inguinal canal, and supplies the fibres of the cremaster muscle, 

 besides sending a few filaments to the other deep coverings of the 

 cord and testicle. 



