ABDOMINAL ARTERIES OF A YOUNG PANDA. 



177 



above, and the source of these abnormalities may be due to an 

 error of development or a pathological cause. Perhaps the bron- 

 chial arteries to the left lung have been occluded by reason of 

 some disease and the coeliac artery has taken their place. If 

 there were an anastomosis between the bronchial, oesophageal, 

 and coeliac vessels, and the former had been occluded, the latter 

 might take their place and pass in from the surface to supply 

 the lung. In time the latter would enlarge and appear as in this 

 specimen. 



I have referred to many books and papers on comparative 

 anatomy and embryology, but I have not found any mention of 

 a similar condition. Chauveau*, after describiug some pecu- 

 liarities of the gastro-pulmonary anastomoses, says, " There are 

 other varieties of which it is unnecessary to speak"; but it is 

 unlikely that he would dismiss such a condition so summarily if 

 he had seen it. 



The Siqyerioy^ Mesenteric Arte?^. 



The unusual feature of the superior mesenteric artery wns the 

 great development of the pyloro-duodenal branch, in order to 

 take the place of the hepatic branch of the coeliac artery. 



This branch passed upwards and to the right to reach the 

 pyloro-duodenal junction. It passed behind it and then curved 

 to the left below the liver, giving off branches to the right and 

 left lobes of the liver, and the gall-bladder. Xone of these vessels 

 entered the portal fissure of the liver. 



The Renal Arteries. 



The right renal artery soon divided into two after its origin 

 from the abdominal aorta, and the left one exhibited a very 

 tortuous course. These are, however, not abnormalities, but 

 merely extreme degrees of a condition common among the 

 Carnivora. 



The reader is referred to page 171, where another peculiarity 

 of the coeliac axis occurs. 



* Chauveau, A. ' Tlie Comparative Anatomy of tlie Domesticated Animals,' 

 page 613. 



Proc. Zool. Soc- 1920, No. XII. 



12 



