TESTICLE (NORMAL ANATOMY). 



arise from" the nearest largest trunks, and 

 enter the substance of the gland at its pos- 

 terior part. The artery of the vas deferens, 

 from which the gubernaculum is chiefly sup- 

 plied, is nearly as large as the spermatic. The 

 long course taken by the arteries and veins of 

 the testicle when in the scrotum is thus ex- 

 plained by the original site of the organ, to 

 which circumstance must also be ascribed the 

 sharp turn upwards of the vas deferens from 

 the epididymis, the two being continuous in a 

 direct line, whilst the testicle is in the ab- 

 domen. 



Fig. 636. 



Diagram of the gubernaculum and testicle previous to 

 its descent. 



1, the kidney ; 2, the testicle ; 3, 3, the peritoneum ' 

 4, vas deferens passing down into the pelvis by the 

 side of the bladder; 5, the bladder; 6, the abdo- 

 minal ring ; 7, 7, Poupart's ligament ; 8, pubic por- 

 tion of the cremaster ; 9, fibres of the cremaster 

 arising from Poupart's ligament ; 10, portion of the 

 guberuaculuui attached to the bottom of the scro- 

 tum. 



Between the fifth and sixth month of foetal 

 existence, sometimes later, the testicle begins 

 to move from its situation near the kidney 

 towards the ring, which it usually reaches 

 about the seventh month. During the eighth 

 month it generally traverses the inguinal 

 canal, and by the end of the ninth arrives at 

 the bottom of the scrotum, in which situation 

 it is commonly found at birth. The testicle, 

 both during its passage to the ring and 

 through the inguinal canal, carries along with 

 it its original peritoneal coat, adhering by the 

 reflexion of this membrane, during the whole 

 of its course to the parts behind, in the same 

 manner as whilst situated below the kidney. 

 The testicle therefore does not pass directly 

 and abruptly into a pouch prepared to receive 

 it, but carries the peritoneum with it, con- 

 tinuing to be connected to the parts behind 

 by the reflexion of the membrane, between 

 the folds of which the vessels and nerves join 

 the gland. In the passage of the testicle from 

 the abdomen to the bottom of the scrotum, 

 the gubernaculum, including its peritoneal 

 investment and muscular fibres, undergoes 

 the same change as that which takes place 

 in certain of the rodcntia at the access of the 

 season of sexual excitement ; the muscle of 

 the testicle is gradually everted, until, when 

 the transition is completed, it forms a mus- 

 cular envelope external to the process of peri- 

 toneum, which surrounds the gland and front 

 of the cord. As the testicle approaches the 

 bottom of the scrotum, the gubernaculum di- 



983 



minishes in size, owing to a change in the dis- 

 position of its areolar elements ; the muscular 

 fibres, however, undergo little or no diminu- 

 tion, and are very distinct around the tunica 

 vaginalis in the recently descended testicle. 

 The mass composing the central part of the 

 gubernaculum which is so soft, lax, and yield- 

 ing, as in every way to facilitate these changes, 

 becomes gradually diffused, and after the 

 arrival of the testicle in the scrotum, contri- 

 butes to form the loose areolar tissue which 

 afterwards exists so abundantly in this part; 

 the middle attachment of the gubernaculum, 

 which may be traced to the dartos at the 

 bottom of the scrotum, gradually wastes away 

 and soon becomes indistinct, though slight 

 traces of this process often remain to the 

 latest period of life. Thus, after death, in 

 dragging the testicle of an adult out of the 

 scrotum by pulling the cord, the lower part 

 of the gland, which is uncovered by serous 

 membrane, is often found connected to the 

 bottom of the scrotum by a band of firm and 

 dense areolar tissue, which requires division 

 with the scalpel. This band is the remains 

 of the middle attachment of the gubernaculum. 

 In cases in which the testicle has been re- 

 tained in the groin, I have traced a cord of 

 dense tissue from the gland to the lower part 

 of the scrotum. After the arrival of the tes- 

 ticle in the scrotum, the peritoneum with 

 which it is closely invested, its original en- 

 velope, becomes the inner layer of the tunica 

 vaginalis ; whilst the pouch around, which is 

 continuous with it, forms the outer layer, or 

 vaginal sac. Immediately after the arrival of 

 the testicle in the scrotum, this bag commu- 

 nicates with the abdomen, and in quadrupeds 

 continues to do so during life ; but in the 

 human subject it soon begins to close, and 

 when the foetus is ushered into the world, 

 the abdominal orifice is often shut, and the 

 whole canal from the ring to the upper part 

 of the gland is, in general, completely obli- 

 terated in the course of the first month after 

 birth. The obliteration is effected by an 

 intimate union of the surfaces of the serous 

 membrane. It sometimes does not take place 

 at all*, or is delayed or only partially com- 



Fig. 637. 



Diagram of the. testicle immediately after its arrival 

 in the scrotum, the cremaster being everted' 



1, the testicle ; 2, the shortened gubernaculum ; 

 3, 3, the peritoneum ; 4 , portion of the cremaster 

 arising from Poupart's ligament ; 5 pubic portion 

 of the nruscle. 



* The communication constantly remains open in 

 quadrupeds, the chimpanzee, according to Professor 



3 R 4i 



