GENERATION. 



down towards the fcrotum : but when the latter and the 

 ligament are drawn downwards, then there is an aperture 

 from the cavity of the abdomen all round the fore-part of the 

 ligament, apparently ready to receive the tcftis. This 

 aperture becomes hirger when the tciUs defceods lower, as 

 if the pyramidal ligament was firft drawn down, in order not 

 only to direft, but to make room for the tcllis, which mull 

 follow it. The aperture is fometimes fo large tiiat theteftis 

 c;m be pufhed into it, as far as the tendon of the external 

 oblique mufclc. 



From this original fituation in the abdomen, the tedis 

 moves downwards, at a certain period, to its deftined ftatioii 

 in the fcrotum. Its lower extremity comes into contadl with 

 the lower part of llie abdominal parietes. At this time, 

 the upper part of the ligament, which hitherto was Ln the 

 abdomen, lias funk downwards, and lies in the paffage from 

 the abdomen to the fcrotum, which is afterwards to receive 

 the teilis. As the latter pafTes out, it inverts the guber- 

 naculum, going down behind it : what was the anterior 

 furfacc of that organ now becomes poRerior, and compofes 

 the lower and anterior portion of the tunica vaginalis. Mr. 

 Hunter Hates, tiiat the place where the ligament is moft con- 

 fined, and where the teilis meets with moil obftruAion in its 

 defcent, is the ring in the tendon of the external oblique muf- 

 cle ; and, confequciilly, that where the tefles are not in the 

 fcrotum, they are more frequently lodged immediately with- 

 in the tendon of that mufcle, than included in the cavity of 

 the abdomen. The teilis commonly remains for fome time 

 by the fide of the penis, and defccnds only by degrees to the 

 bottom of the fcrotum. AVhen it has entirely defcended, 

 the ligament is no longer vifible. 



While the teilis is deleending, and even when it has palTed 

 into the fcrotum, it is dill covered by the peritoneum, and is 

 connefted by its pollerior edge exactly in th.e fanie manner 

 as when it was within the abdomen. The fpermatic vefTels 

 run in the fame way behind the membrane, the teflis is fixed 

 backwards to the parts againll which it rells, and is uncoii- 

 nefted and loofe forwards, as it was when in the abdomen. 

 In its defcent the teilis brings the peritoneum with it ; but 

 the elongation of that membrane, though itrefembles, in fome 

 circumftances, a common hernial fac, in others is very dif- 

 ferent. If a perfon can reprelent to himfelf a hernial fac 

 reaching to the bottom of the fcrotum, and covered by the 

 cremafter ; if he can imagine, further, that the pollerior 

 half of the bag covers, and is united with the teilis, epi- 

 didymis, fpermatic veflels, and vas deferens, while its anterior 

 half lies loofe before all thofe parts, he will have a perfeft 

 idea of the ftate of the peritoneum and of the teilis when it 

 firft. defcends into the fcrotum. This gland, therefore, does 

 not fall loofe, like the parts protruded in a rupture, into the 

 elongation of the peritoneum ; but it Aides down from the 

 loins, carrying the peritoneum with it, and both continue to 

 adhere, by cellular membrane, to the parts behind them, as 

 they did in the loins. The dudlility of the peritoneum, and 

 the loofeuefs of its conneclion to the parts furrouuding the 

 teflis, are clrcum. unices which favour its elongation and de- 

 fcent into the fcrotum with the tedis. 



It is plain, from this defcription, that the cavity of the 

 bag, or elongation of the peritoneum, which contains the 

 tetlis in the I'crolum, mull at tirll communicate with the 

 general cavity of the abdomen, by an aperture at the abdo- 

 minal ring. That aperture has exactly the appearance of a 

 common hernial fac : the fpermatic veflels and vas deferens 

 lie inimediately behind it, and a probe patfes readily through 

 it from the general cavity of the abdomen down to the 

 bottom of the fcrotum. And if this procefs of the perito- 

 neum he laid open through its whole length on the fore-part, 



it will be plainly feen to be a continuation of the peritoneum r 

 the teilis and epididymis will be feen at the lower part of it ; 

 and the fpermatic veffels and vas deferens may be obferved, 

 covered by the pollerior part of the bag, in their whole 

 courfe from the groin to the tcRis. 



Before the teilis has quitted the abdomen, the fcrotum is 

 fmall and corrugated, and contains nothing but cellular 

 fubilance. This i.s loofe, and yielding near the ring, but 

 more denie and clofe below. Some have defei'ibcd a pouch 

 of peritoneum pafTing through the ring, and therefore con- 

 tained in the fcrotum, previoufly to the defcent of tlie teflis : 

 but this is noi generally corrccl. There is no fuch poucli 

 while the gland remains near the kidney. The parts about 

 the ring are furrounded by fuch a loofe and cellular texture, 

 that, by drav.ing the gubernaculum downwards, the perito- 

 neum is carried with it fo as to reprcfent a fmall cul-de-fac. 

 The teilis, too, after it has pafled the ring, may be drawn up 

 again into the abdominal cavity, in confequence of this laxity 

 of the furrounding fubilance. 



In the human body then, when the teflis has recently 

 come down, it is contained in a membranous bag, formed of 

 an elongation of the peritoneum, and communicating with, 

 the abdomen by means of a narrow procefs, afcending in 

 fs-ont of the fpermatic cord. The parts remain in this 

 condition throughout life in the quadruped, but in man the 

 communication betv.'een the membranous covering of the 

 teilis and the abdomen is foon cut off. The upper end of 

 the canal is doled lirft, and the aperture is obliterated fo 

 fpeedily, that there is leldom any communication in a child 

 born at its fall time. 1'he procefs of contradlion is conti- 

 nued downwards, along the cord, to the upper end of the 

 teilis, at which it flops. Thus the tunica vaginalis teflis, 

 which was in the iirfl inflance a produfticn of peritoneum, 

 becomes entirely feparated from that mem.brane ; the peri- 

 toneal covering of the gland is the re.<lecled tuniea vagi- 

 nalis. 



" This contraftion and obliteration of the pafTage feems," 

 fays Mr. Hunter, " to be a peculiar operation of nature, 

 depending upon fleady and uniform principles, and not tlie 

 confequence of inflammation, or of any thing that is acci- 

 dental : and, therefore, if it is not accompliilied at the proper 

 time, the difficulty of bringing about an union of the pirt 

 is much greater : as in children who b.ave had the fac kept 

 open by a turn of the intettine falling down into the fcrotum 

 immediatelyaftertlie teflis.'' "The clofing of themouth, and 

 of the neck of the fac, is peculiar to the human fpccies ; 

 and we mull fuppofe the final caufe to be the prevention of 

 ruptures, to v>'hich men are fo much more liable than beatls, 

 from their ereft flate of body.'' We feel fome hcfitation in 

 admitting this reafoning as to the caufe of obliteration : at 

 all events, if we fhould acknowledge it, the frequent occur- 

 rence of ruptures mull prove that nature accoinplifhes her 

 end very imperfeclly. " What !" fays the fame priyflolo- 

 gilt; " is the immediate caufe of the defcent of the teflis 

 from the loins to the fcrotum ? It is evident t'nat it cannot 

 be the comprefTed force of refpiration, becaufe commonly 

 the teilis is in the fcrotum before the child has breathed ; 

 that is, the efFeft has been produced before the fuppofed 

 caufe has exifled. Is the teflis pulled dov.-n by the cre- 

 maller mufcle ? I can hardly fuppofe that it is. Becaufe, 

 it that was the cafe, I fee no reafon why it fhould not take 

 place in the hedge-hog, as well as in other quadrupeds ; and 

 if the mufculus teilis had this power, it could not bring it 

 lower than the ring of the mufcle.'' 



The procefs, which we have now defcribed, is liable to 

 fome variations. In fome individuals, the neck of the peri- 

 toneal elongation is not obliterated, fo that the tunica vagi- 



