308 THE ADRENAL, GENERAL MOTOR, AND VAGAL SYSTEMS. 



they would give rise, besides, to disturbances in all parts of 

 the organism to which its subdivisions are distributed. Any 

 practitioner is familiar with the fact that a violent emotion 

 immediately after a meal will arrest digestion, followed by its 

 attending phenomena, but give rise to no other symptoms. 

 The vagus center merely fails, under such circumstances, to 

 supply the added energy for the active function, and the 

 food lies in a passive stomach. We have seen that in the ex- 

 periments of Pawlow and Schumowa-Simanowskaja, referred 

 to by Howell, the "fictitious meal," though it passed out of 

 an artificial opening in the oesophagus, nevertheless caused in 

 dogs a "psychical" secretion of gastric juice. Cutting of the 

 two vagi in these animals, however, prevented its flow: strong 

 evidence in itself that the vagus system is the ruling one dur- 

 ing digestion. Finally, and even more to the point, are the 

 experiments of Contejean, referred to by Onuf and Collins in 

 the following words: "Contejean in experimenting upon frogs 

 found that the pneumogastric nerve has a stimulating influence 

 upon the secretion of gastric juice, the sympathetic having but 

 little effect in this direction." Alluding to the results of per- 

 sonal experiments, these investigators further say: "Inci- 

 dentally we may mention that this conclusion is in harmony 

 with the results obtained by Contejean on the stomach of 

 frogs." 



A feature not to be overlooked in this connection is the 

 practical independence of the suprarenal system. Its vast im- 

 portance in the organism necessarily involves freedom from 

 individual organs. As regards the stomach, we can readily 

 see that the mere constriction of the extrinsic vessels is suffi- 

 cient to hasten the speed of the blood-flow and the metabolism 

 of the intramural structures. 



This does not mean that all fibers of the motor system 

 are passive factors; indeed, it is probable that during peri- 

 staltic action the two nerves, by transmitting impulses of vary- 

 ing relative intensity, may underlie the motions observed. The 

 cardiac end of the stomach, for instance, is mainly supplied by 

 motor fibers. 



Vomiting is an interesting symptom in this connection. 

 Toxics, we have seen, increase suprarenal activity to a more or 



