THE STOMACH AND INTESTINE. 



23 5 



down between the glands, and are arranged in the form of a net- 

 work just above the muscularis mucosse, but with coarser meshes 

 than that formed by the blood-vessels. Here the valves begin to 

 make their appearance. The lymph-vessels pass through the mus- 

 cularis mucosae and in the outer portion of the submucosa form a 

 plexus with open meshes, from which are derived the efferent ves- 

 sels which penetrate the muscular coat and thus gain access to the 

 mesentery. In their course through the muscular coat they com- 

 municate with the branches of a plexus of lymph-vessels situated 

 between the two muscular layers, and also with lymph-vessels found 

 in the serous coat. 



H Central chyle- 

 vessel of vil- 

 lus. 



~~f"f~ Chyle-vessel. 



Vein. 



Mucosa. 



Muscularis 



mucosse. 



Submucosa. 



Plexus of 

 lymph -ves- 

 sels. 



Circular mus- 

 cular layer. 



Plexus of 

 lymph-ves- 

 sels. 



Long. muse. 



layerwiththe 



serous coat. 



Fig. 224. Schematic transverse section of the human small intestine (after F. P. Mall). 



The lymphatics of the small intestine begin in the axes of the 

 villi. When filled, these lymph-vessels are conspicuous, irregularly 

 cylindric capillary tubules, lined by endothelial cells, and known as 

 the axial canals, the chyle-vessels, or \helacteals of the villi. They 

 are hardly discernible when collapsed. If the villus be broad, it 

 may contain two chyle-vessels, which then join at the apex of the 

 villus, and may also be connected with each other by a few anasto- 

 moses. At the base of the villus the chyle-vessel enters a lymphatic 

 capillary network, the structure of which is due to the confluence 



