XXVII.-ON GALVANOTROPISM 

 By 



Sir J. C. BosE, 

 Assisted by 



GURUPRASANNA DaS. 



Before describing the effect of unilateral application 

 of an electrical current in inducing tropic curvature, I 

 shall give an account of the polar effect of anode and 

 cathode on the pulvinated and growing organs. In my 

 previous work * on the action of electrical current on 

 sensitive pulvini I have shown that : — 



(1) at the 'make' of a current of moderate intensity 



a contraction takes place at the cathode ; the 

 anode induces no such contractile effect ; 



(2) at the ' make ' of a stronger current both the 

 anode and cathode induce contraction. 



I have also carried out further investigations on the 

 polar effect of current on the autonomous activity of the 

 leaflet of Desmodimn gyrans. These rhythmic pulsations 

 can be recorded by my Oscillating Recorder. Each pulsa- 

 tion consists of a sudden contractile movement downwards, 

 corresponding to the systole of a beating heart, and a 

 slower up movement of diastolic expansion. Application of 



""Irritability of Plants." p. 21'.>. 



