INNERVATION OF THE DIGESTIVE TUBE 183 



In similar preparations of the small intestine sympathetic fibers 

 may be traced into close proximity with the digestive glands and 

 not infrequently such fibers could be observed among the gland- 

 cells. There can be little doubt, therefore, that some of these 

 fibers form physiological contact with cells of the digestive glands. 

 Many of the sympathetic fibers reaching down from the sub- 

 mucous plexus may be traced beyond the level of the digestive 

 glands into the gastric folds and plicae or the intestinal villi where 

 many of them terminate on cells of the digestive epithelium. 



Fig. 3 Terminations of sympathetic nerve-fibers. A, on smooth muscle- 

 cell; B, on cells of digestive epithelium, ileum of cat; C, on cells of digestive 

 epithelium, stomach of cat; D, on parietal cell, stomach of cat. A and B, Leitz, 

 obj. 1/16, oc. 4; C and D, Leitz, obj. 1/12, oc. 4. 



These terminations are very delicate, but in good methylene blue 

 preparations thej^ may be observed without difficulty under high 

 magnification. In methylene blue preparations of the stomach 

 and the small intestine of the cat, terminations of this kind could 

 not infrequently be observed on several adjacent epithelial cells. 

 The sympathetic fibers extending into the gastric folds and plicae 

 and the intestinal villi lie in the tunica propria close to the diges- 

 tive epithelium. The tenninal portions of these fibers or lateral 

 branches given ofT by them deviate from the course of the fiber- 



