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THE MUCOUS MEMBRANE. 

 FIG. 21. 



The columnar form of epithelium is also found in all the 

 glandular ducts, whose bases are often surmounted with 

 cilite, (Fig. 22,) whose motions are directed towards the 

 FIG. 22. outlets of the canals they line. 



The second coat, the proper mu- 

 cous, called also the papillary or 

 basement membrane, resembles 

 the papillary layer of the skin, 

 and is a membrane apparently without texture. Its sur- 

 face presents different aspects at different points. 



In the stomach it forms cells or alveoli, into which the 

 follicles open. In the intestines it presents numerous pro- 

 jecting points, having a velvety appearance and called 

 villi, while in the large intestines it again, as in the 

 stomach, assumes the shape of cells. This coat is exceed- 

 ingly soft and spongy, easily destroyed either by mechani- 

 cal violence or the action of acids, which reduces it to a 

 pulpy state. 



The fibrous layer, called also the sub-mucous and nervous, 

 forms the third layer of mucous membrane. It corresponds 

 to the corium of the skin, in giving support and strength to 

 the mucous layer, and contains numerous capillary vessels, 

 nerves and absorbents. 



It has just been stated that the mucous membrane has 

 upon its papillary surface numerous conical projections, 



FIG. 21 represents cylinders of the Intestinal Epithelium. 



1 Cylinders from cardiac region of the human stomach. 2 Cylinders from 

 jejunum. 3 Cylinders seen from their free extremity. 4 Cylinders as seen in 

 a transverse section of a villous. 



FIG. 22, Ciliated Epithelium. 6 Cilia upon the top of a epithelium. 



