1768 



HUMAN ANATOMY. 



neum downward to constitute a sac that descends behind the tunica vaginalis, 

 especially if the latter is capacious, as it is apt to be when its upper limit is at the in- 

 ternal ring. A hernia of this variety has, therefore, between the skin and the con- 

 tents three layers of serous membrane, two of the tunica vaginalis and one of peri- 

 toneum (its own sac) connected >vith one another at the neck. Not uncommonly, 

 however, — as might be expected from the tendency of serous membranes to adhesive 



Fig. 1488. 



Fig. 1489. 



Peritoneum 

 Spennatic cord 

 'Skin and fascia 



Hernial sac 



Peritoneum 

 Spermatic cord 

 Skin and fascia 



Diagram of congenital hernia, showing relation of 

 hernial sac to peritoneum. 



Tunica vaginalis 



Diagram of infantile hernia, showing relation of 

 hernial sac to tunica vaginalis. 



inflammation, — the posterior layer of the tunica vaginalis is intimately blended with 

 the front wall of the sac. Infantile hernia, while due, like the congenital variety, to 

 anomaly in development, is even less apt to exist at birth and, in fact, is rarely seen 

 in infancy. A variety of infantile hernia known as the encysted (Fig. 1490) is de- 

 scribed, in which the intestine depresses the septum at the internal ring, making a 

 sac which passes into instead of behind the processus vaginalis, so that the hernia 

 has in front of it a layer of tunica vaginalis and a layer of septum (sac). This 

 hernia is very properly described (Lockwood, Macready) as "a figment of the 

 imagination. ' ' When, after occlusion of the process at the internal ring only, the 

 septum gives way suddenly during some unusual intra-abdominal pressure, the intes- 

 tine may descend at once into instead of behind the tunica vaginalis and lie in, con- 

 tact with the testicle, — a form of " congenital" hernia that appears in adult life. 



Fig. 1490. 



Fig. 1491. 



Peritoneum 

 Spermatic cord 

 , Skin and fascia 



Peritoneum 

 Spermatic cord 

 Skin and ^cia 



Hernial sac 



unica vaginalis 



Diagftam of so-called encysted hernia, showing sup- 

 posed relation of hernial sac to peritoneum. 



Diagram of funicular hernia, showing relation of 

 hernial sac to tunica vaginalis. 



Funicular hernia (Fig. 1491 ) is a sequence of the closure of the vaginal process 

 at the upper end of the epididymis only, the short pouch of peritoneum remaining 

 in communication with the peritoneal cavity. The contents of such a hernia are 

 separated from the testicle by the septum formed at the point of closure. 



Interparietal (intraparietal, interstitial) hernia is so usually a variety of oblique 

 inguinal hernia, and is so commonly associated in the male with anomalies of the 



