196 PLANT RESPONSE 



as will be seen later, is due to the depressing action of a strong 

 anode. There was no action at the anode itself at make ; at 

 break, there was no action near the kathode, but there was 

 excitation at the anode, as was shown by the fall of three 

 contiguous pairs of leaflets. The direction of the current was 

 now changed, the poles being thus reversed, and eight pairs of 

 leaflets fell at the new kathode, in and out. There was, how- 

 ever, no effect at the new anode at make ; but at break, the 

 reverse was the case, leaflets falling near the anode, and no 

 response occurring at the kathode. This experiment was 

 repeated three times on the same specimen, and the results 

 were in every case similar. I give (fig. 93) a pair of records 



FlG. 93. Records of Responses of Leaflet of Biophytum, showing 

 Responses occurring at Kathode at Make and not at Break ; and at 

 Anode at Break and not at Make 



in Biophytum leaflet, showing the opposite character of the 

 effects of make and break at the anode and kathode respec- 

 tively. The E.M.F. used in this particular experiment was 

 sixteen volts. 



In the former series of experiments, it was seen that 

 there was no break-anode effect when the E.M.F. was 

 feeble. The present experiments show us that the break- 

 anode is effective when the E.M.F. is moderately strong. 



I obtained similar effects when stimulation was produced 

 by means of condenser discharge, the experiments being 

 carried out on Biophytum. 



From the investigation just described, it will be seen 

 that with moderate EM.F. we obtain response from the 



