chap, xvii.] ABDOMINAL BLOOD-VESSELS. 371 



understood that great enlargement of those bodies 

 may cause oedema from pressure. 



A number of minute but most important anasto- 

 moses exist between some of the visceral branches 

 of the abdominal aorta and certain of the vessels 

 supplied to the abdominal parietes. These anasto- 

 moses are situated behind the peritoneum, and 

 mostly concern such viscera as have a fair surface 

 uncovered by that membrane. The visceral branches 

 that join the anastomoses are derived from the hepatic, 

 renal, and suprarenal arteries, and from the vessels 

 supplying the lower part of the duodenum, the pan- 

 creas, the caecum, and the ascending and descending 

 segments of the colon. The parietal vessels joining 

 with the above are derived from the phrenic, lumbar, 

 ilio-lumbar, lower intercostal, epigastric, and circum- 

 flex iliac trunks. In a case detailed by Professor 

 Chiene (Journ. Anat. and Phys., vol. iii.) the coeliac 

 axis and mesenteric vessels were plugged, but blood 

 in sufficient amount to supply the viscera had reached 

 the branches of these arteries through their parietal 

 communications. The anastomosis gives an anatomical 

 demonstration of the value of local blood-lettings and 

 of counter-irritants in inflammatory affections of 

 certain of the viscera, and also a scientific basis to the 

 ancient practice of poulticing the loin and the iliac 

 region in nephritis and in inflammation about the 

 caecum. 



Cases have been recorded of communications 

 between the external iliac vein and the portal vein. 

 These have generally been effected by the deep 

 epigastric vein joining with a pervious umbilical vein 

 in the vicinity of the navel. 



Thoracic duct. Some six cases of wound of 

 this duct have been reported, the injury being usually 

 a stab. In each case lymph and chyle in large 

 quantities escaped from the wound. In one instance 



