296 SURGICAL APPLIED ANATOMY. [Cimp xvi 



of the rectus may be much stretched, since they bear 

 the brunt of the distending force. The direction of 

 the fibres also renders them liable to be torn in the 

 opisthotonos, or extreme arching of the back, of 

 tetanus. Portions of the muscle have also been 

 ruptured by muscular violence. 



The lateral muscles of the front abdominal wall 

 are separated from one another by layers of loose 

 connective tissue. These extensive layers favour 

 the spread of interstitial abscesses of the abdominal 

 parietes. Such abscesses will be guided in their 

 course by the attachments of the muscles between 

 which they spread, and will be limited by the semi- 

 lunar lines in front, by the lower parts of the ribs and 

 their cartilages above, by Poupart's ligament and the 

 iliac crest below, and by the edge of the erector 

 cpinae behind. The same remark applies to hsemorr- 

 hagic or emphysematous collections between these 

 muscles. 



Between the abdominal parietes and the perito- 

 neum is a layer of loose connective tissue, the sub- 

 serous connective tissue. The looseness of this 

 layer greatly favours the spread of abscess, to the 

 progress of which it offers little resistance. Such an 

 abscess may spread from the viscera, especially from 

 those that have an imperfect peritoneal covering, as, 

 for example, the kidney, the vertical parts of the colon, 

 etc. The laxity of this tissue is of great service in 

 certain surgical procedures. Thus the external and 

 common iliac arteries can be reached by an incision 

 made some way to the outer side of the vessels and 

 without opening the peritoneum. That membrane 

 having been exposed in the lateral wound, the artery 

 is reached by working a way with the finger through 

 the subperitoneal tissue, and by actually stripping 

 the serous membrane from its attachments. This 

 condition of the subserous layer also favours that 



