128 



DR RUTHERFORD ON THE INFLUENCE OF THE VAGUS 



Time after Division 

 of Vagi. 



Distance of Primary from 



Secondary Coil of Induction 



Machine. 



Nerve Stimulated. 



Result as regards Gastric 

 Vascularity. 





mm. 







7' 



200 



Upper end of right vagus 

 irritated for 30". 



Slight reddening. 



12' 



150 



Upper end of right vagus 



Pallor succeeded by well- 







irritated for 30". 



marked redness. 



15' 



120 



Upper end of right vagus 

 irritated for 15". 



The same result. 





Chloroform was now given until complete anaesthesia resulted. 



20' 



120 



Upper end of right vagus 



Slight increase of pallor suc- 







irritated for 30". 



ceeded by well-marked 

 redness. 



24' 



80 



Upper end of right vagus 



The same result. 







irritated for 30". 





Experiment XXXI. — Cat which had fasted for sixteen hours. The blood- 

 vessels of the outer surface of the stomach were small and contracted. Division 

 of the nervi depressores and vagi produced no apparent change in the vascu- 

 larity of the stomach or intestines. Irritation of the upper end of the vagus 

 caused tolerably distinct blushing of the gastric wall. 



The general result of the experiments just given is, that section of the vagi 

 produces no change in the gastric blood-vessels if these be not in a dilated con- 

 dition, such, e.g., as obtains during digestion, while division of these nerves 

 during dilatation of the gastric vessels is generally followed by marked and 

 permanent contraction of these vessels. It is true that this result did not occur 

 in one (experiment xxvii) of the five experiments in which the nerves were 

 divided during digestion. In that case, however, it was quite evident that the 

 gastric vessels were not so dilated as they usually are ; but, of course, such a 

 statement is not without fallacy, seeing that every case cannot be identical as 

 regards the vascular dilatation that obtains during digestion. I am not, there- 

 fore, prepared to give any decided opinion regarding the results of experiment 

 xxvii ; but it seems clear that the general result of the effects of division of the 

 vagi supports the idea that, during digestion, vaso-inhibitory influences pass in 

 a centripetal direction through the vagi. The effects of irritating the cut ends 

 of the nerves were various. It is certain that no evident change in the vascu- 

 larity was ever produced by stimulating the lower ends of the nerves, so we 

 may safely say that the influences which pass through the nerves to control the 

 gastric vessels certainly do not pass in a centrifugal direction. When the upper 

 ends of the nerves were subjected to sufficiently powerful stimulation, pallor of 

 the gastric wall sometimes followed, at other times blushing ; frequently the 

 blushing succeeded the pallor, and sometimes no perceptible effect resulted. 



