THE ABDOMINAL WALLS 267 



The Epididymis begins in an enlargement which is situated 

 on the upper pole of the testis. This is termed the Head (globus 

 major), and it receives the efferent ducts of the testis, which 

 unite to form the convoluted Ducts of the Epididymis. The 

 body, which contains the downward continuation of the duct, 

 is much narrower than the head, and is closely applied to the 

 lateral aspect of the posterior border of the testis (Fig. 81). 

 Interiorly, the epididymis again enlarges to form the Tail 

 (globus minor}, and from its medial side the duct emerges as 

 the ductus (vas) defer ens, with greatly thickened walls. This 

 structure ascends along the medial side of the epididymis and 

 is closely related to the terminal branches of the internal 

 spermatic artery. At the upper pole of the testis the ductus 

 deferens enters the spermatic cord. 



Development of the Testis and Epididymis. Prior to the develop- 

 ment of the permanent kidneys, the embryo possesses two primitive kidneys, 

 the Wolffian bodies, which communicate with the cloaca by the Wolffian 

 ducts. The testis develops in close relation to the Wolffian body, and, as the 

 Wolffian body atrophies, the efferent ducts of the testis become connected 

 to the Wolffian duct, which forms both the epididymis and the ductus deferens 

 (p. 394). Most of the tubules of the Wolffian body disappear and the few 

 which persist constitute the Paradidymis or Organ of Giraldes, which is 

 situated in the lower part of the spermatic cord, just above the head of the 

 epididymis. The Mullerian ducts, which play such an important part in the 

 formation of the female generative organs (p. 394), disappear almost entirely 

 in the male. Each is represented by two Appendices Testis (the Hydatids of 

 Morgagni), which lie at the upper pole of the testis just in front of the epi- 

 didymis. Both the paradidymis and the appendices testis may give rise to 

 cysts, which frequently contain spermatozoa and are termed spermatoceles. 

 The prostatic utricle (sinus pocularis) represents the fused caudal ends of the 

 two Mullerian ducts. 



In Hydrocele of the tunica vaginalis, fluid collects in the 

 sac and gradually distends it above, in front, and on each side 

 of the testis, giving rise to a somewhat egg-shaped swelling. 

 The testis and epididymis lie posterior to it, but in rare cases 

 inversion of the testis may be present. In this condition the 

 epididymis is related to the anterior border and the tunica 

 vaginalis to the posterior border and lateral surfaces of the 

 testis, while the ductus deferens occupies an anterior position 

 in the cord (Treves). Before tapping a hydrocele it is important 

 to determine the position of the testis with reference to the 

 swelling. The trochar and cannula are pushed through the 

 skin of the scrotum anteriorly in an upward and backward 

 direction. The distended tunica vaginalis is pierced from in 

 front (to avoid the testis) and near its lower pole (to facilitate 

 the evacuation of its contents). Care must be taken not to 



