THE VENOMS OF CERTAIN T II A N A T PHI D E M. 



REMARKS 



23 00 



Injected peptone from 0.03 gram dried venom. 



Dead. 



REMARKS. 



Pneumogastric nerves and cord cut. Injected intravenously 

 the peptone from 0.015 gram dried venom of the Crotalus 

 adamanteus. 



REMARKS. 



Pneumogastric nerves and cord cut. Injected intravenously 

 the peptone from 0.015 gram dried Cobra venom. 



j- Injected a similar dose. 



Dead. 



In the above series of experiments with venom peptones we find results which 

 agree with those in which the pure venoms were used. We conclude, therefore, 

 that the peptones cause a primary increase and a secondary diminution of the 

 pulse-rate, and that they occasion primary hastening of the heart beat by excita- 

 tion of the accelerator centres in the medulla, and that the impulses are carried 

 through fibres passing chiefly by the spinal cord. This increase is more marked 

 after section of the pneumogastric nerves, thus suggesting that this principle has 

 some direct or indirect effect upon the pneumogastric centres, tending to slow the 

 action of the heart and to neutralize the accelerator influence. Peptones cause 

 the diminution of the heart beat by a direct action on that organ. 



