298 THE ADRENAL, GENERAL MOTOR, AND VAGAL SYSTEMS. 



be considered as showing that the secretion obtained when the 

 vagi were intact was due to a reflex stimulation of the stomach 

 through these nerves. In later experiments 2 from the same 

 laboratory the secretion caused in this way by the act of eating 

 is designated as a 'psychical secretion/ on the assumption, for 

 which considerable evidence is given, that the reflex must in- 

 volve psychical factors, such as the sensations accompanying 

 the provocation and gratification of the appetite. In favorable 

 cases the fictitious feeding was continued for as long as five to 

 six hours, with the production of a secretion of about 700 cubic 

 centimeters of pure gastric juice. Finally, these observers 

 were able to show that direct stimulation of the vagi 3 under 

 proper conditions causes, after a long latent period (four and 

 a half to ten minutes), a marked secretion of gastric juice. 

 The long latent period is attributed to the simultaneous stim- 

 ulation of inhibitory fibers." Howell closes his review of this 

 subject by the remark: "Taking these results together, we 

 must believe that the vagi send secretory fibers to the gastric 

 glands, and that these fibers may be stimulated reflexly through 

 the sensory nerves of the mouth, and probably also by psychical 

 states/' 



That oral sensory nerves and psychical states may reflexly 

 cause increase of secretion of gastric juice we deem demon- 

 strated, not only by experimental physiology, but also by the 

 teachings of clinical experience. As to the nature of the 

 stimuli through which this is caused, the newer conceptions 

 recorded in this work fully sustain the results referred to by 

 Howell when he says, in the foregoing review: "In the hands 

 of most experimenters stimulation of the vagi and of the sym- 

 pathetics has given negative results, and, on the other hand, 

 section of these nerves does not seem to prevent entirely the 

 formation of the gastric secretion." And, paradoxical as this 

 may seem, there is no ground to doubt the accuracy of Pawlow 

 and Schumowa-Simanowskaja's observation that electrical 

 stimulation of the vagus gave rise to a marked secretion of 

 gastric juice. Still, it seems to us that, had wire been dis- 



1 Pawlow and Schumowa-Simanowskaja: "Die Arbeit der Verdauungsdrii- 

 ," \Viesbaden, 1898. 

 All italics are our own. 



