76 INGUINAL HERNIA. 



Oblique inguinal hernia is a protrusion of intestine through a 

 passage originally made by the escape of the testicle from.the loins to 

 the scrotum, and afterwards occupied by the spermatic cord. Until 

 the seventh month of fostal life the testicle reposes in the lumbar 

 region beneath the kidney, but not within the cavity of the perito- 

 neum. As yet there is no spermatic cord formed, the constituents, 

 to wit, the artery, vein, duct, &c., each approaching the testicle 

 separately. About this period the testicle ordinarily descends, by 

 means of a contractile structure attached to its inferior extremity, 

 until it is enveloped in the scrotum, in its passage it must come in 

 contact with the various structures forming the parietes of the abdo- 

 men, viz., the peritoneum, fascia transversalis, the transversalis, 

 internal and external oblique muscles, the superficial fascia, and the 

 skin. Now each of these structures, with the exception of the ex- 

 ternal oblique muscle, will be found to form a covering for the testicle 

 and cord, because it does not perforate them, but pushes them before it ; 

 although this covering may be modified in some degree, nevertheless 

 there is a representation of every layer of the walls of the abdomen ; 

 and this is the case not only in the covering of the testicle and cord, 

 but also in the covering of a hernial protrusion ; hence, if a student 

 understands the changes which take place in the descent of the 

 testicle, he must necessarily understand the mode by which a hernial 

 protrusion obtains its coverings. 



Here we must caution students from attaching too much impor- 

 tance to words or terms used in description, for they vary with diffe- 

 rent writers ; but let him keep constantly belore his mind the thing 

 itself, as if he were making a dissection ; for by actual dissection 

 he can understand it thoroughly, although he may not know the 

 name of a single point. 



In the first place, by the contraction of the gubernaculum testis, 

 the testicle is brought in contact with the peritoneum, and since it is 

 not in the peritoneal cavity, it must necessarily push before it a doubled 

 Inmma of peritoneum. Thus the testicle gets a covering of serous 

 membrane arranged as serous membranes always are ; that is, one 

 lamina covers the testicle, and the other lines the cavity in which it 

 is contained, and it is called the 2Jeri/cs/ is or timica vaginalis testis. 

 The comaiunication between the peritoneum and peritestis is oblite- 

 rated, otherwise the bowel could readily pass down ; and when 

 this does occur, it constitutes a variety of hernia, termed congenital. 

 As the testicle descends, the spermatic artery, vein, and vas deferens 

 descend with it, and thus the cord is formed ; the components are 

 held together by means of cellular tissue, formerly the canal of 

 peritoneum, connecfinii; the peritoneum and peritestis. Organs that 

 have been of use in the system are never entirety absorbed, but 

 converted into another which serves a different purpose — as in the 

 case of an artery when tied for aneurism, it becomes a cord ; the um- 

 bilical vein becomes the lio amentum teres. 



