THE ABDOMEN. 



383 



from Meckel's diverticulum to the umbilicus and causes strangulation of other coils 

 of the intestine. We have operated on one such case. The umbilical vein becomes 

 obliterated and the small vein found in the round ligament of adults, called by Schiff 

 \ho. par umbilical, is a new formation, and not the original fetal umbilical vein. 



Infantile umbilical hernia is the common form which appears soon after birth. 

 It does not contain omentum so constantly as does adult hernia, because it does not 

 hang so low, nor is it so well developed. 



Acquired umbilical hernia is the form seen in adults. The presence of the 

 urachus and hypogastric arteries so strengthens the lower edge of the umbilical ring 

 that hernial protrusions make their exit above, hence the hard edge of the ring is 

 nearer the lower end of the hernial sac. 



These herniae almost always contain omentum, and either transverse colon or 

 small intestine. The contents of the herniae are usually matted together and 

 are adherent. The coverings are very thin, consisting of skin and peritoneum, 

 with a small amount of transversalis fascia and scar-tissue between. Unless~extreme 

 care is exercised in operating, the first cut will pass into the sac and wound the intes- 

 tines or omentum. There are two modes of operating on these herniae. In one 

 operation the sheaths of the two recti muscles are opened and the muscular fibres and 

 sheaths are brought together and sewed in the median line; in the other, two flaps 



Vaginal Funicular Encysted 



FIG. 394. The various forms of congenital inguinal hernia. 



Infantile 



are made from the fibrous walls of the sac and lapped one over the other, thus clos- 

 ing the hernial opening by two fibrous layers. This may be done either longitudin- 

 ally or transversely. 



Inguinal Hernia. There are two forms of inguinal hernia, the congenital and 

 the acquired. These are subdivided into several varieties which can only be under- 

 stood by having a knowledge of the development and construction of the parts involved. 



Development and Descent of the Testis. The testicle originates in the lumbar 

 region inside of the abdomen about the third month. It is behind the peritoneum 

 and has a fold of peritoneum, the plica vascularis, passing upward from it, containing 

 the spermatic artery and veins, and a fold passing downward to the inguinal region 

 and into the scrotum called the gubernacuhim. By the fifth or sixth month the testicle 

 has reached the abdominal wall at the internal ring, after which it enters the inguinal 

 canal to pass into the scrotum in the eighth or ninth month of fetal life. A 

 process of peritoneum the vaginal process precedes the passage of the testicle into 

 the scrotum. The neck of the vaginal process is called the funicular process. Soon 

 after birth the vaginal process becomes occluded, first at the internal ring, and thence 

 downward until the testicle is reached, where the unobliterated portion forms the 

 tunica vaginalis testis. 



Congenital Hernicz and Hydrocele. There are several forms of congenital 

 herniae. They are so named, not because they exist from birth, but because they 

 are caused by developmental defects which exist at birth (Fig. 394). 



