224 RESEARCHES ON IRRITABILITY OF PLANTS 



carrying out the experiments, I found that the excitation 

 took place at make of kathode and break of anode only. 

 I give a sketch showing these effects of kathode-make and 

 anode-break (fig. 114). The figure at the left shows the 

 depression of leaflets starting from the kathodic point 

 which was on the left. After their recovery the circuit was 

 broken and excitation is seen to have taken place at the 

 anode, on the right, and not at the kathode, on the left. 

 Thus the leaflets of Biophytum, with a moderate current, 



K A 



Fig. 114. — Illustration to the left shows excitation induced by the make 

 of kathode, that to the right the effect of break of anode. 



gave the same reaction as the leaflets of Mimosa, the 

 excitatory formula in both being Km Ab. I carried out 

 more than fifty experiments on the effect of moderate 

 currents on the leaflets of Biophytum, and the results 

 without a single exception were as has been described. 



The tabular statement below shows the results due to 

 a current of moderate intensity on leaflets of Biophytum 

 as given in the typical experiment. Each experiment, it 

 should be remembered, was carried through the usual cycle 

 of direct and reverse currents. 



Table V. — Effect of Moderate Current on Leaflets of Biophytum 

 E.M.F. = 22 volts; current = 2"i micro-amperes 



Experiments made on leaflets of other plants, in which 



