220 STUDIES ON RESPIRATION. V 



CO2 output is accompanied by irreversible changes leading to death, 

 while this is not necessarily the case in plants. The reversible (nar- 

 cotic) action of ether on the animals studied was accompanied by a 

 decrease in the carbon dioxide output; in plants this is not ordinarily 

 the case. 



These facts are of considerable interest, but their interpretation 

 must be left to future investigation. 



