INNERVATION OF THE DIGESTIVE TUBE 



189 



in the ner\'ous control of the digestive functions can hardly be 

 avoided. 



The ner\^ous mechanism in the walls of the digestive tube is 

 connected with the cerebro-spinal nervous system primarily by 

 the vagi and the splanchnics. In general the vagi act in an excit- 



FSg. 5 Schematic diagram illustrating probable relationships of sympathetic 

 neurones in myenteric and submucous plexuses. Motor neurones, stippled; sen- 

 sory neurones, solid. 1, tunica propria; 2, muscularis mucosae; 3, submucosa; 4> 

 muscularis; M, myenteric plexus; S, submucous plexus; a, axones; d, dendrites. 



atory and the splanchnics in an inhibitory manner on the diges- 

 tive organs. The recent work of Cannon ('06) and Auer ('10) 

 shows that the vagi possess both excitatory and inhibitory fibers 

 for the digestive tube. The work of these investigators shows, 

 furthermore, that while the splanchnics are not necessary for the 



