INTESTINE. 189 



fibres, the innermost of which run circularly, while the outer 

 fibres take a longitudinal course. From the inner layer muscle 

 fibres run between the Lieberkiihn's glands into the villi. 



Fio. 144. 



Villi 



\ Submucosa 



-Muscularis 

 Transverse section through a Peyer's patch from a cat's small intestine. X 25. 



These are supposed on contraction to shorten the villi and to 

 aid in forcing the chyle, etc., from the villi to the large lymph- 

 atic vessels. 



The submucosa consists of firm connective tissue, with glands 

 only in the region of the duodenum. These are the so-called 

 Brunner's glands (Figs. 140 and 142). They are branched 

 tubular glands whose entire bodies are situated in the sub- 

 mucosa, and whose ducts pierce the mtiscularis mucosae and 

 open between, or into Lieberkulm's glands. These are occasion- 

 ally found, not only in the duodenum, but also in the pyloric 

 end of the stomach, just as pyloric glands are sometimes found 

 in the duodenum. The Brunner's glands are recognized easily 

 by the fact that they break through the muscularis mucosa3 and 

 into the submucosa. The cells of Brunner's glands are cylin- 



