i 4 RESPONSE IN THE LIVING AND NON-LIVING 



It may, however, be that this limitation is not justi- 

 fied, and surely, at least until we have explored the 

 whole range of physical action, it cannot be asserted 

 definitely that a particular class of phenomena is by its 

 very nature outside that category. 



Electric response in plants. But before we proceed 

 to the inquiry as to whether these responses are or are 

 not due to some physical property of matter, and are to 

 be met with even in inorganic substances, it will perhaps 

 be advisable to see whether they are not paralleled by 

 phenomena in the transitional world of plants. We 

 shall thus pass from a study of response in highly com- 

 plex animal tissues to those given under simpler vital 

 conditions. 



Electric response has been found by Munck, Burdon- 

 Sanderson, and others to occur in sensitive plants. But 

 it would be interesting to know whether these responses 

 were confined to plants which exhibit such remarkable 

 mechanical movements, and whether they could not 

 also be obtained from ordinary plants where visible 

 movements are completely absent. In this connection, 

 Kunkel observed electrical changes in association with 

 the injury or flexion of stems of ordinary plants. 1 My 

 own attempt, however, was directed, not towards the 

 obtaining of a mere qualitative response, but rather to 

 the determination of whether throughout the whole 

 range of response phenomena a parallelism between 

 animal and vegetable could be detected. That is to 



1 Kunkel thought the electric disturbance to be due to movement of 

 water through the tissue. It will be shown that this explanation is in- 

 adequate. 



