THE ABDOMEN. 233 



give tlie faeces its peculiar odour. The intestines of tlie 

 horse are about ninety feet in length, and as the posterior 

 eighteen feet are much larger in calibre than the rest, it is 

 divided into the large and the small intestine. The small intes- 

 tine commences from the pyloric extremity of the stomach, 

 and just after its commencement becomes very large. It 

 is here termed the duodenum, and takes an upward direc- 

 tion over the posterior concave surface of the liver, to the 

 porta of which it is attached by a continuation of the 

 gastro-hepatic omentum, between the two layers of which 

 the duct common to the liver and the pancreas runs to the 

 attached margin, and then, after passing beneath the peri- 

 toneal coat, opens on the free margin through a perforated 

 papilla into the intestinal canal, about four inches from 

 the pylorus. Passing in an upward direction, the duo- 

 denum takes a curve around the head or right extremity 

 of the pancreas (termed its horse-shoe curve), and then, 

 passing underneath the spine behind the anterior mesen- 

 teric artery, terminates. The rest of the small intestine 

 occupies no regular position in the abdomen, for, being 

 attached in the free margin of the mesentery, it hangs 

 loose, but terminates in the right lumbar region, where it 

 opens into the large intestine, the muscular coat being here 

 doubled in such a manner as to form the ileo-csecal valve, 

 which prevents food from passing from the large into the 

 small intestines under ordinary circumstances. The ante- 

 rior two fifths of this portion of the small intestine is 

 termed the jejumtm, and the posterior three fifths the 

 iletmi. This division is purely artificial, and anatomists 

 now prefer to describe the fixed or duodenal, and the free 

 portions of the small intestine. The mucous coat of the 

 duodenum presents, in addition to papillae, follicles of 

 Lieberklihn, and solitary glands (extremely rare here), 

 certain small racemose glands, in every respect resembling 

 salivary glands, even, it is supposed, in the nature of their 

 secretion, of which, however, nothing definite is known, 

 these are named Brunner's glands, after their discoverer. 

 On the free margin of the ileum and of the posterior part 

 of the jejunum may be seen elongated patches, apparently 

 of pigmentary matter. These are Peyer's patches, and 

 when examined microscopically are found to be aggrega- 

 tions of solitary glands surrounded by a row of fol- 

 licles of Lieberklihn termed the corona tubulorum, while 



