450 DISSECTION OF THE PIGEON. 



mid -dorsal line of the thorax and abdomen. Its 

 principal branches are as follows : 



i. The coeliac artery is a median vessel which arises 

 about the level of the auriculo-ventricular 

 septum of the heart It runs back in the 

 mesentery, and divides into branches which 

 supply the stomach, gizzard, and part of the 

 intestine. 



ii. The anterior mesenteric artery is a median 

 vessel, which arises about a quarter of an 

 inch behind the cceliac artery, and runs back- 

 wards in the mesentery, dividing into branches 

 which supply the greater part of the length 

 of the intestine. 



iii. The anterior renal arteries are a pair of small 

 vessels, which arise from the aorta opposite 

 the anterior ends of the kidneys, and supply 

 their anterior lobes. From the artery of the 

 left side a branch is given off to the ovary. 



iv. The femoral arteries are paired, and arise oppo- 

 site the anterior lobes of the kidneys. They 

 pass outwards, dorsal to the kidneys, to supply 

 the extensor muscles of the thigh. Each gives 

 off a pubic artery, which runs backwards 

 along the ventral border of the pubes. 



v. The sciatic arteries are a pair of larger vessels 

 which arise opposite the middle lobes of the 

 kidneys : they pass outwards and backwards, 

 between the middle and posterior lobes of 

 the kidneys, and through the ilio -sciatic 

 foramina, to supply the flexor muscles of the 

 thighs and the muscles of the legs. 



Each sciatic artery gives off a middle 

 renal artery to the middle lobe of the kidney, 

 and a posterior renal artery to the posterior 

 lobe. 



