THE INTESTINE 



431 



fokl, except at the terminal part. Here there are two short folds, one of which 

 joins the mesocolon; the other passes onto the terminal part of the colon. The 

 first part of the mesoduodenum contains the right branch of the pancreas. Its 

 root is blended with the mesocolon to form a common mesentery. The remainder 

 of the small intestine forms numerous coils, and is attached by a wide mesentery 

 to the sublumbar region. The pancreatic and bile ducts open into the duodenum 

 about two or three inches (ca. 5 to 8 cm.) from the pylorus; the accessory pancreatic 

 duct opens an inch or two (ca. 2.5 to 5 cm.) further back. The mucous membrane has 

 very long villi. The duodenal ( Brunner's) glands occur only near the pylorus. Peyer's 

 patches are numerous (about twenty in young subjects), and begin in the duodenum. 

 They are usually elliptical in outline, but the last one is band-like, reaches to the end 



Fig. 33fi. — Deep Dissection of Abdominal Viscera of Dog (Female). 



BL, Bladder; B, body; C, C, cornua of uterus; O, O', ovaries; L. K., left kidney. The concealed part of the coloa 



is indicated by dotted lines. (From photograph of formalin-hardened subject.) 



of the ileum and is four to sixteen inches (ca. 10 to 40 cm.) long in young dogs (Ellen- 

 berger). There is an ileo-caecal valve.^ The muscular coat is relatively thick. 



The large intestine is two to two and a half feet (ca. 60 to 75 cm.) long. 

 Its caliber is about the same as that of the small intestine, and it has neither longi- 

 tudinal bands nor sacculations. 



The caecum is about three or four inches (ca. 8 to 10 cm.; long, and is twisted 

 in a spiral fashion. The twist is maintained by the peritoneum, which attaches it 



' The valve does not seem to be efficient, since experience shows that rectal injections can 

 be made to pass beyond it. This may be partly due also to the fact that the terminal part of the 

 ileum runs horizontally forward, and the ileo-csecal orifice faces into the beginning of the colon. 



