MULTIPLE AND AUTONOMOUS ELECTRICAL RESPONSE 219 



electrical recovery takes place ; but before this is complete, 

 and while there is still a certain residual galvanometric 

 negativity, there occurs that more intense and short-lived 

 excitatory reaction which finds mechanical expression in the 

 downward-movement. The same reaction finds electrical 

 expression in a brief and intense response of galvanometric 

 negativity ; on the expenditure of this excitatory impulse 

 there is again an electrical recovery, which becomes prac- 

 tically complete. 



In the instance given in the spark-record, it was found 

 that the relative intensity of the down to the up impulse was 

 approximately as 1*5 is to i. And it is interesting to see 

 that in the photographic record of the electrical responses 

 (fig. 144), the ratio of the amplitudes of the corresponding 

 electrical waves is also the same. In other instances, the 

 relative intensity of the principal wave is still higher. I give 

 below two tables showing the absolute values of the electro- 

 motive variations in two different cases. 



TABLE I. 



TABLE II. 



It might be thought that these two electrical waves had 

 been induced by the mechanical movement of the leaflet as 

 such. We have seen, however, that the electrical response 

 is a concomitant of the excitatory condition, whether such 

 excitation be followed by any mechanical response or not. 

 This we saw in the absence of mechanical movement in the 

 case of ordinary plants. The same was found also in the 



