400 



STUDIES ON RESPIRATION. VI 



in a 7.3 per cent (by volume) solution of ether. These changes are 

 shown in Table I. 



The CO2 output of Salvia involucrata was measured by the methods 

 used in the previous investigation. The petals^ were immersed in tap 

 water and the normal respiration was determined. The petals were 

 then immersed in a solution of 7.3 per cent ether (by volume) and new 

 determinations were made. The results are shown in Fig. 1. 



Objection might be made to submerging the petals in liquid on the 

 ground that this condition is abnormal and that gas might be given 

 off more rapidly through the stomata when ether is present (as the 

 result of changes in surface tension). For this reason it seemed de- 



TABLE I. 



Changes in the pH Value of Salvia Petals during the Process of Death Caused by 

 Immersion in Solution of 7.3 Per Cent Ether (by Volume). 



sirable to repeat the experiments by the method described by Oster- 

 hout.^ As flowers of Salvia involucrata were no longer available 

 Salvia splendens was used. The corollas were placed in a glass tube, 

 the normal respiration was measured, and sufficient ether was then 

 introduced into the apparatus to saturate the air with ether vapor 

 at 20°C.^ The rate of respiration was then determined at frequent in- 

 tervals. In respect to the per cent of increase produced by ether the 

 results agreed closely with those shown in Fig. 1. 



* In all the experiments the entire corolla was used, care being taken to detach 

 it with as Httle injury as possible. 

 5 Osterhout, W. J. V., /. Gen. Physiol., 1918-19, i, 17. 

 ^ The petals were at no time in contact with liquid. 



