84 



THE VENOMS OF CERTAIN THANATOPHIDEA 



Normal 



Normal 



Time: 



Pulsations 



min. sec. 



per minute. 



17 00 



190 



17 30 





19 30 



187 



21 30 



190 



23 30 



180 



25 30 



170 



31 30 



165 



34 30 





it No. 67. 





Time : 



Pulsations 



min. see. 



per minute. 





282 









15 



276 



20 





30 



264 



1 00 



264 



1 30 



246 



2 00 



234 



it No. 68. 





Time: 



Pulsations 



min. sec. 



per minute. 





324 









11 



300 



40 



318 



1 40 



276 



5 40 



272 



10 40 



276 



15 40 



306 



16 00 





16 06 





16 15 



306 



16 25 



300 



17 00 



276 



18 00 



270 



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. 



Injected a similar dose. 



23 00 



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. 



