no TOPOGRAPHICAL ANATOMY OF THE 



(2) A. colica media. — The middle colic artery is scarcely, if at all, 

 larger tlian one of the intestinal arteries, and consequently might be 

 mistaken for a branch of the dorsal colic artery since both vessels arise 

 from a short common stem. The middle colic artery is distributed to the 

 terminal part of the great colon and a short length of the small colon . . 

 the mesentery of which it anastomoses with the left colic artery. 



(3) A. colica dorsalis. — There can be little question that this vesse 

 should be regarded as the equivalent of the right colic artery of the dog. 

 It is of large size and is conveniently called " dorsal " because of its 

 distribution to the dorsal colon (right and left parts). 



(4) A. ileoccecocolica. — The ileo-caeco-colic artery is the largest 

 branch of the cranial mesenteric, and, as its name implies, is the vessel 

 that supplies blood to the caecum and ventral colon as well as part of 

 the ileum. It divides into two vessels — the ventral colic and ileo-caecal 

 arteries. 



(0) The ventral colic artery (a. colica ventralis) supplies the ventral 

 colon (right and left parts) and anastomoses with the dorsal colic at the 

 pelvic flexure. 



(h) The ileo-coical artery (a. ileoctecalis) furnishes an iliac branch 

 (ramus iliacus) which carries blood to the terminal part of the ileum and 

 anastomoses with the last intestinal artery. Lateral and medial ca'cal 

 branches (rami ciecales) proceed along the corresponding surfaces of the 

 cajcum to its apex, and frequent anastomoses occur between them. The 

 lateral csecal branch furnishes twigs to the commencement of the ventral 

 colon. 



A. MESENTERICA CAUDALIS. — Very niuch smaller than the cranial 

 mesenteric, the caudal mesenteric artery leaves the ventral border of the 

 abdominal aorta opposite the fourth lumbar vertebra. Running for a 

 short distance between the two peritoneal layers of the mesentery of the 

 small colon, it soon divides into the left colic and cranial haemorrhoidal 

 arteries. 



(1) A. colica sinistra. — The left colic artery divides into three or 

 four branches that behave like the intestinal arteries in that they form 

 arterial arches just before reaching the intestine. The first branch 

 anastomoses with the middle colic artery. 



(2) A. hcemorrhoidalis cranialis. — The cranial ha-morrhoidal 

 artery supplies branches to the terminal part of the small colon and the 

 rectum, ending close to the anus where it anastomoses with the internal 

 pudendal artery. The first four or five branches continue the series of 

 arches begun by the left colic artery. 



Vv. MESENTERICA CRANIALIS ET CAUDALIS. — The tributaries of 



