CHAPTER XVII 



MULTIPLE AND AUTONOMOUS ELECTRICAL RESPONSE 



Repeated responses under single strong stimulus Multiple mechanical response 

 in Biophytu'm Multiple electrical responses in various animal and vegetable 

 tissues Continuity of multiple "and autonomous response Transition from 

 multiple response to autonomous, and vice -versa Autonomous mechanical 

 response of Desmodium gyrans and its time-relations Simultaneous 

 mechanical and electrical records of automatic pulsations in Desmodium 

 Double electrical pulsation, principal and subsidiary waves Electrical 

 pulsation of Desmodhim leaflet under physical restraint Growth-pulsation 

 So-called current of rest in growing plants. 



WE have seen that when a plant organ is acted on by a 

 single stimulus of sufficient intensity, it exhibits a single 

 excitatory effect, which may show itself in two independent 

 ways, as mechanical and electrical response. We have also 

 seen that part of the impinging stimulus may become latent, 

 to find appropriate expression later. It was also shown 

 that with increasing intensity of stimulus the amplitude of 

 response reaches a limit. It may thus happen that a very 

 strong stimulus, not finding adequate expression in a single 

 response, will exhibit itself by means of repeated responses. 

 The incident energy in such cases is held latent for a 

 time, 1 to manifest itself later in a rhythmic manner. 



I have been able to demonstrate the occurrence of this 

 multiple excitation, in response to a single strong stimulus, 

 by several different and independent methods. The simplest 

 and most striking of these depends on the recording of the 

 motile effects in the leaflets of Biophytum. In fig. 135 are seen 

 no less than sixteen multiple pulsations resulting from a single 

 strong thermal stimulation of the petiole bearing the leaflets. 

 1 For more detailed account see Bose, Plant Response, pp. 279-357. 



