THE ACTION OF VENOMS UPON THE PULSE-RATE. 79 



pulse after section of the pneumogastric nerves. If the increase in the pulse-rate 

 in normal animals is due for the most part to excitation of the accelerator centres, 

 whereby impulses are generated which pass chiefly through the accelerator fibres 

 running in the spinal cord, it would seem probable that the accelerator impulses 

 induced by the globulins take for the most part the course of the fibres through 

 the pneumogastric nerves, but are much feebler than the impulses which are gene- 

 rated by the pure venoms, and which take their path chiefly through the fibres in 

 the spinal cord. 



After section of both the pneumogastric nerves and cervical spinal cord, we 

 found in all of our experiments a diminution in the heart-beats; this must be due 

 to a direct action of the globulin upon the heart. 



It therefore seems probable that the globulins cause a primary increase of the 

 pulse by an excitation of the accelerator centres, whereby impulses are conveyed 

 principally by the accelerator fibres passing through the pneumogastric nerves; 

 and a diminution of the heart beats by a direct action on the heart. 



Section III. — The Actions of Venom Peptones upon the Pulse-Rate 



The Action of Venom Peptones on the Pulse-rate. — In seven experiments made 

 with peptone on normal animals — four with the peptone from the venom of the 

 Crotalus adamanteus ; one with that of the Ancistrodon piscivorus ; and two with 

 that of the Cobra — we find results which vary and which resemble closely those 

 obtained by the administration of pure venom. In three experiments there was a 

 primary increase of pulse followed generally by a diminution ; in three the pulse 

 remained below normal ; while with Ancistrodon peptone there was a primary fall 

 of rate followed by a rise. 



The differences in the results, as in previous experiments, do not seem to 

 depend at all upon the dose or the variety of venom from which the peptone was 

 obtained. 



Experiment No. 55. 

 Normal 



Time : 



Pulsations 





min. 



sec. 



per miuute. 









280 



Injected intravenously ; 





20 



102 



venom of the Grotahu 





30 



190 







40 



190 







50 



190 





1 



00 



180 





3 



00 



190 





6 



00 



340 



Struggles. 



11 



00 



285 



Struggles. Broke loose, 



49 



00 





Dead. 



