1296 



THE UBO-GENITAL SYSTEM. 



fold, termed the plica inguinalis (or plica inguino-mesonephrica), is joined from above 

 by a less marked fold (the plica testis inferior) which extends downwards from the 

 inferior end of the testis, which, at this time, is situated in the abdomen close to the inner 

 aspect of the mesonephros. Within both these folds smooth muscular and fibrous tissue 

 arises and gives origin to a continuous band, or ligament the gubernaculum testis. 

 The gubernaculum is, therefore, to be regarded as originally composed of two portions 

 a part developed within the plica inguinalis, and a part formed within the plica testis 

 inferior. It is interesting to note that in the female the representatives of these two parts 



of the gubernaculum remain separate i 

 throughout life, and constitute the round 

 ligament of the uterus and the ligament 

 of the ovary. The gubernaculum, when 

 it is at its greatest development (about 

 the sixth month), is rounded and cord-like, 

 and is attached above to the lower end of 

 the testis, while inferiorly it is fixed near 

 the inguinal region. In the lower part 

 of its course it is closely related to, and is 

 FIG. 1015. DIAGRAM to illustrate the descent of the part iy COV ered by, the peritoneum of the 



processus vaginalis. Striped muscular 

 scrotum, fibres are present in the lower part of the 



t.v. Tunica vaginalis. gubernaculum, and have their origin from 



the muscles of the inguinal part of the 

 anterior abdominal wall. As the testis 

 enters the processus vaginalis the gubernaculum atrophies, but at birth a short part of j 

 the gubernaculum may still be found passing downwards towards the inferior part of the i 

 scrotum and lying below the level of the tunica vaginalis. It is considered by some] 

 anatomists that the movement downwards of the testis may be partly due to a pull caused] 

 by the shrinking of the gubernaculum as it atrophies. 



In some mammals, such as the elephant, the testes remain permanently within thej 

 abdominal cavity ; while in others, such as the rabbit and the hedgehog, the peritoneal 

 pouches remain widely open throughout life, and the testes are periodically withdrawn^ 

 into the abdomen. 



testis and the manner in which the tunica vaginalis 

 is derived. 



a.c. Abdominal cavity. 

 p.v. Processus vaginalis. 

 t. Testis. 







External spermatic fascia 



I Internal spermatic fascia 

 Testicular 



artery p amp i n if O ri] 

 ,, plexus 



FUNICULUS SPERMATICUS (SPERMATIC CORD). 



The testis in its course downwards through the abdominal wall into t 

 scrotum takes with it its duct the ductus deferens blood and lymph vessels, and 

 nerves of supply. All these lie together in the inguinal canal as they traverse the 

 abdominal wall, and when they leave the canal by the subcutaneous inguinal rin 

 they extend downwards to the posterior border of the testis. The ductus deferens 

 the spermatic "vessels, and the nerves and 

 lymph vessels of the testis, loosely con- 

 nected together, form the funiculus sper- 

 maticus, or spermatic cord. At the ab- 

 dominal inguinal ring its constituent parts 

 separate from one another, and the funi- 

 culus may therefore be considered to extend 

 from the abdominal inguinal ring to the 

 posterior border of the testis. The struc- 

 tures which form the spermatic cord are en- 

 closed within a number of coverings derived 

 from the layers of the anterior abdominal 

 wall, and these, when the constituents of Fia 

 the cord reach the posterior border of the 

 testis, surround the tunica vaginalis, and 

 so form a part of the wall of the scrotum. 

 The sheaths or coverings of the cord derived from the abdominal wall are three i 

 number, and are named external spermatic fascia, fascia cremasterica, and inte 

 spermatic fascia. The external spermatic fascia is the most superficial of 

 three sheaths, and is derived from the aponeurosis of the external oblique mu 



Deep fascia 



Ductus deferens ! ^^ 

 Artery to ductus deferens 



1016. TRANSVERSE SECTION OF THE 

 CULUS SPERMATICUS, OR SPERMATIC 

 JUST BELOW THE SUBCUTANEOUS 

 RING. 



