194 MESSKS. BEDDARD AKD TEEVES ON THE 



with that part of the colon that has been already described as adhering to the 

 parietes. Between the segment of the duodenum and the colon the great or 

 mesenteric artery passed. 



The Mesenteric Arteries 

 in all essential points resembled the corresponding vessels in the Horse. The great 

 mesenteric gave off from its left side the vasa intestina for the small intestine and 

 the colica media. 



The former branches each formed a single arch before entering the bowel. The latter 

 artery supplied the transverse colon and upper part of the descending colon and ended 

 by joining with the lesser mesenteric artery. 



From the right side of the main trunk were derived the inferior pancreatico-duodenal 

 artery and the two arteries of the colic loop (1 and 2, fig. 1, PL XXXIV.). These 

 vessels came ofF separately from the great mesenteric. On their way to the loop they 

 were buried in the adhesions that connected the base of the caecum with the root of the 

 incoming limb of the loop. The artery of the outgoing segment (2, fig. 1) ran upon the 

 bowel itself; the corresponding vessel for the other segment (1, fig. 1) ran in a serous 

 membrane that connected the two parts of the loop. The two arteries joined at the bend 

 of the loop and gave off branches at regular intervals of two inches to supply the colon. 



A remarkable azygos artery (3, fig. 1, PI. XXXIV.) ran parallel with the artery of the 

 outgoing limb. It was contained on the free margin of a separate fold of peritoneum, 

 was of the same size from its commencement to its end, and served to connect not only 

 the two colic arteries together but also the respective extremities of those vessels. It 

 gave oflF no branches of any kind. It would appear that the connecting vessel placed 

 in a special fold would serve the purpose of carrying on the circulation, in the event of 

 the colic arteries becoming occluded by pressure or by reason of extreme bending of 

 the colic loop. 



In size this vessel was equal to the ulnar in the human subject. The artery of the 

 arch of the caecum (4, fig. 2, PL XXXIV.) has already been alluded to. The superior 

 caecal artery had a distribution identical with that of the vessel of the same name in 

 the Horse, and the same observation applies to the inferior caecal artery (5, fig. 2, 

 PL XXXIV.) 



With the superior caecal artery arose the ileo-colic that was distributed to the 

 terminal part of the ileum and ended by joining the last of the vasa intestina. 



The lesser or inferior mesenteric artery approached the bowel 3 feet from the anus. 

 Its mode of distribution difiered in no respect from the corresponding vessel in the 

 Horse. 



Heart. 



The heart presented nothing unusual in its structure ; the apex was markedly bifid ; 

 the right auriculo-ventricular valve has the same structure as has been recorded by 



