STRUCTURE OF THE INTESTINE 



147 



fibres of the circular muscular layer on the one side, and the mucous mem- 

 brane on the other side so as to leave only the submucous tissue and the 

 niuscularis mucosae. This tissue is also to be mounted flat in Farrant's 

 solution : it contains the plexus of Meissner. 



Sketch a small portion of each plexus under a high power. 



3. Sections of the large intestine, perpendicular to the surface. These 

 will show the general structure and arrangement of the coats. Sketch under 

 a low power. 



4. Sections of the mucous membrane of the large intestine parallel 

 to the surface, and therefore across the glands. Sketch some of the glands 

 and the interglandular tissue under a high power. 



5. The arrangement of the blood-vessels of the large intestine may be 

 studied in sections of the injected organ. 



THE SMALL INTESTINE. 



The wall of the small intestine consists, like the stomach, of four 

 coats. 



The serous coat is complete except over part of the duodenum. 



FIG. 178. PLEXUS OF AUERBACH, BETWEEN THE TWO LAYERS OF THE MUSCULAR 



COAT OF THE INTESTINE. (Cadlat.) 



The muscular coat is composed of two layers of muscular tissue, an 

 outer longitudinal and an inner circular. Between them lies a net- 

 work of lymphatic vessels and also the close gangliated plexus of non- 



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