INTESTINE. 191 



which surrounds the gland tubules, and passes over into a 

 venous network which is situated in the tunica propria. From 

 here the veins enter the submucosa, where they join to form 

 large vessels which leave the intestine by paths similar to that 

 taken by the arteries in entering. From the submucosa also 

 other branches from the large arteries pass downward into the 

 muscular coats. The relations of the vessels of the stomach tis 

 demonstrated by F. P. Mall are shown in Figs. 145 and 146. 



In the small intestine there are small arteries proceeding 

 from the subglandular network to enter the villi. One or 

 sometimes two arteries run in the centre of the villus to its end, 

 giving out on the way side branches which form a capillary 

 network. The branches of this network join near the per- 

 iphery of the villus to form veins, which descend to join the 

 subglandular plexus of veins. 



The Brunner's glands are surrounded by a network of capil- 

 laries derived from the submucous branches. The lymph folli- 

 cles gain their blood supply partly from the subrnucous 

 branches and partly from the plexus in the tunica propria. 



The beginning of the chyle vessels is between the glands in 

 the stomach and large intestine, and in the axis of the villi in 

 the small intestine. In the upper part of the villus the lymph- 

 vessels end blindly and show a certain degree of anastomosis. 

 These join to form the central chyle vessel or lacteal. Around 

 the Lieberkiihn's glands there are numerous lymphatics, which 

 form a thick network below. This is in combination with a 

 second coarser network in the submucosa. The efferent vessels 

 pass through the muscularis, collecting the fluid from numerous 

 lymphatics in the muscle and from a lymphatic plexus between 

 the muscle layers. The lymph-vessels leave the intestine 

 between the two layers of the mesentery. Around the follicles 

 the lymph-vessels form a network with sinus-like dilatations. 



The nerves of the alimentary canal arise mainly from the 

 sympathetic system. The non-medullated fibres enter at the 

 mesenteric border, pierce the external muscle layer, and form a 

 peculiar plexus between this and the internal muscle coat. This 

 is called the plexus myentericus or Auerbach's plexus. Where 



