336 



AVES. 



aorta, even higher than the zone of the gastric 

 glands. It descends obliquely for a short way, 

 and then gives off a branch which soon divides 

 into two or three others that are spread upon 

 the lower part of the oesophagus, and the side 

 of the zone of the gastric glands, uniting with 

 the other arteries of the oesophagus above, and 

 extending downwards upon the posterior side 

 of the ventricle, and anastomosing with the an- 

 terior gastric artery. The trunk of the coeliac 

 now divides into two very large branches, 

 which from their distribution we have chosen 

 to call the posterior and the anterior gastric 

 arteries. 



"The posterior gastric artery, almost as soon 

 as it is formed, detaches the splenic artery ; 

 and very soon after it furnishes from the poste- 

 rior side of the vessel the right hepatic artery. 

 This brancli proceeds to the right lobe of the 

 liver, which it enters on the side of the hepatic 

 duct ; after having divided into two or three 

 minute arteries on its way to the liver, it sup- 

 plies the hepatic duct with a branch which 

 accompanies the duct to the intestine, and is 

 there lost. The posterior gastric artery then 

 runs down upon the back of the gizzard, and 

 opposite to the origin of the first intestine it 

 sends offan artery , which proceeds directly to one 

 of the cceca(in the Fowl), upon whichand the side 

 of the next intestine it is expended, inosculating 

 at the end of the coecum with branches of the 

 mesenteric artery, which are distributed to the 

 adjoining portion of the small intestine. The 

 posterior gastric then furnishes a large vessel 

 which runs upon the gizzard, and divides into 

 two chief branches, which penetrate the sub- 

 stance of the digastric muscle, in which they 

 are lost. 



" The next branch of the posterior gastric 

 artery is the pancreatic. It runs between the 

 two pancreatic glands, dispensing branches to 

 each and to the duodenum. After this the 

 trunk of the posterior gastric divides into two 

 branches, which furnish twigs to the muscular 

 parietes of the ventricle, and run along the 

 margins of the upper and lower portions of the 

 digastric muscle. Supplying them with nume- 

 rous twigs, and anastomosing with the ramifi- 

 cations of the other gastric arteries. 



" The anterior gastric artery descends to the 

 angle formed by the bulbus glandulosus and 

 the gizzard, and there sends off a small branch 

 which spreads upon the zone of the gastric 

 glands, and inosculates with the first ramifica- 

 tions of the cceliac, and immediately afterwards 

 it detaches a large artery, which runs round the 

 superior margin of the digastric muscle, which 

 it furnishes with many twigs, and communi- 

 cates freely with the corresponding branch of 

 the posterior gastric artery. 



" Three small hepatic arteries take their 

 origin from this branch of the anterior gastric, 

 just as it passes over the highest part of the 

 margin of the gizzard ; these vessels enter the 

 fissure in the left lobe of the liver. The ante- 

 rior gastric artery now proceeds along the fore 

 part of the gizzard, sending one or two brandies 

 into the muscular substance, and near the ten- 



don it terminates in two large vessels, one of 

 which is distributed upon the left side of the 

 digastric muscle, and the other passes a little 

 over the tendon, and then divides into two 

 arteries, which produce several branches that 

 disappear in the substance of the gizzard, and 

 between the digastric muscles and the parietes 

 of the ventricle, anastomosing with the vessels 

 of the posterior side. 



" The superior mesenteric artery (2 1 ,Jig. 1 70) 

 takes its origin from the fore part of the aorta, a 

 little below the coeliac, and proceeds for some 

 way without detaching any branches; after 

 which it experiences the same kind of division 

 and subdivision that takes place in mammalia ; 

 and the numerous arteries which are thus ulti- 

 mately produced are spent upon the small intes- 

 tines. One of the first and largest branches of 

 the superior mesenteric, however, is allotted to 

 supply one of the cceca, and to establish a com- 

 munication with the inferior mesenteric and 

 gastric arteries. This branch, soon after it 

 leaves the trunk of the superior mesenteric, 

 divides into two. One descends upon the rec- 

 tum, where it meets with the inferior mesenteric 

 artery, with which it produces a very remark- 

 able anastomosis, similar to the mesenteric arch 

 in the human subject ; this united artery sup- 

 plies the rectum and origin of the cceca. The 

 second portion of this branch of the superior 

 mesenteric runs in the space between the last 

 part of the small intestine and the coecum of 

 one side, sending numerous branches to each, 

 and at the end of the coecum communicates in 

 a palpable manner with another branch of the 

 superior mesenteric artery, which runs upon the 

 adjoining part of the small intestine. 



"A branch (22, Arteria spermaticu) arises 

 from the anterior part of the aorta, just below 

 the lungs; it is designed for the nutrition of 

 the organs of generation, and except in the 

 season for propagation, it is so small as to 

 be discovered with difficulty ; but when the 

 testicles become enlarged, it is considerably 

 increased in size in the male bird, and much 

 more so in the female, when the ovary and 

 oviduct are developed for producing eggs. It 

 nearly equals the superior mesenteric artery 

 during the period of laying, in which state we 

 shall describe it. It is a single artery, like the 

 coeliac and mesenteric, proceeds at a right angle 

 from the aorta, and soon sends off a branch, 

 which goes into the kidney of the left side, to 

 which it gives some twigs, and afterwards 

 emerging from the kidney, it runs in the mem- 

 brane of the oviduct, upon which it is distri- 

 buted. After this branch is detached, the 

 artery projects a little farther forwards into 

 the cavity, and divides into two branches; one 

 of these goes to the ovary, in which it ramifies, 

 and furnishes an artery of some size to each of 

 the cysts containing the ova. The other is dis- 

 tributed in numerous branches to the mem- 

 brane and superior parts of the oviduct, and 

 inosculates with the other arteries of the 

 oviduct. It deserves to be remarked, that this 

 and all the other arteries which are furnished 

 to the oviduct have a tortuous or undulating 



