DUCT OF TESTIS. 483 



The epididymis (fig. 169, //) extends in the form of an arch along the 

 outer side of the testis, from the upper to the lower end, and receives its 

 name from its situation. Opposite the upper part of the testicle it pre- 

 sents an enlarged portion or head, the globus major (g~) ; and at the lower 

 end of that organ it becomes more pointed or tail-like globus minor ('), 

 before ending in the vas deferens. The intervening narrow part of the 

 epididymis is called the body (h). Its head is attached to the testis by 

 the vasa etferentia ; and its lower part is fixed to the tunica albuginea by 

 fibrous tissue, and by the reflection of the tunica vaginalis. 



The epididymis is formed of a single tube, bent in a zigzag way, whose 

 coils are united into a solid mass by fibrous tissue. After the removal of 

 the serous membrane and some fibrous tissue this part of the tube may be 

 uncoiled; it will then measure twenty feet in length. The diameter of its 

 canal is about ^th of an inch, though there is a slight diminution in size 

 towards the globus minor, but it is increased finally in the vas deferens. 



The vas deferens (fig. 169, k) begins opposite the lower end of the tes- 

 tis, at the termination of the globus minor of the epididymis. At first this 

 part of the excretory duct is slightly wavy, but afterwards it becomes for 

 the most part a firm round tube: near its termination it is enlarged again 

 and sacculated, but this condition will be referred to with the viscera of 

 the pelvis. 



In its course to the urethra it ascends on the inner side of the testicle, 

 and along the bloodvessels of the spermatic cord with which it enters the 

 internal abdominal ring; it is then directed over the side of the bladder, 

 and through the prostate to open into the urethra. The length of this 

 part of the exci-etory duct is about two feet, and the width of its canal 

 about ^th of an inch. 



Opening sometimes into the vas deferens, at the angle of union with the 

 epididymis, is a, small narrow crecal appendage, the vas aberrans of Haller 

 (fig. 169, /). It is convoluted, and projects upwards for one or two inches 

 amongst the vessels of the cord. Like the epididymis, it is longer when 

 it is uncoiled : its capacity is greatest at the free end. Its use is unknown. 



Structure. The excretory duct of the testis has a thick muscular coat, 

 which is covered externally by fibrous tissue, and lined internally by mu- 

 cous membrane. To the feel the duct is firm and wiry, like whip-cord. 

 On a section its wall is dense and of a rather yellow color, but it is thinnest 

 at the head of the epididymis. 



The muscular coat is composed of longitudinal and circular fibres ar- 

 ranged in strata. Both externally and internally is a longitudinal layer, 

 the latter being very thin ; arid between them is the layer of circular fibres. 



The mucous membrane is marked by longitudinal folds in the straight 

 part of the canal, and by irregular ridges in the sacculated portion. A 

 columnar epithelium, though not ciliated) covers the inner surface ; but in 

 the epididymis it is ciliated (Becker). 



Organ of Giraldes. 1 In the spermatic cord of the foetus and child, close 

 above the epididymis, is a small whitish granular-looking body (" Corps 

 Innomine," Giraldes), about half an inch long the remains of the lower 

 part of the Wolffian body of the embryo. With slight magnifying power 

 its component white granules are resolved into small vesicles, and convo- 

 luted tubes of varying shape, filled with a clear thick fluid; their wall 



1 Sur un Organe place dans le Cordon Spermatique, et dont I'existence n'a pas 

 ete signalee par les Anatomistes. Par F. Giraldes. Proceedings of the Royal 

 Society for May, 1858. 



