60 RESPONSE IN THE LIVING AND NON-LIVING 
mine whether the undoubted changes induced by tem- 
perature in the vital activity of plants wi affect 
electrical response. 
Effect of very low temperature.—As regards the 
influence of very low temperature, | had opportunities 
of studying the question on the sudden appearance 
of frost. In the previous week, when the tempera- 
ture was about 10° C., I had obtained strong electric 
response in radishes whose value varied from ‘05 to 
‘1 volt. Buttwo or three days later, as the effect of the 
frost, I found electric response to have practically 
disappeared. A few radishes were, however, found 
somewhat resistant, but the electric response had, even 
in these cases, fallen from the average value of ‘075 V. 
under normal temperature to ‘005 V. after the frost. 
That is to say, the average sensitiveness had been 
reduced to about ,%. On warming the frost-bitten 
radish to 20° C. there was an appreciable revival, as 
shown by increase in response. In specimens where 
the effect of frost had been very great, i.e. in those 
which showed little or no electric response, warming 
did not restore responsiveness. From this it would 
appear that frost killed some, which could not he 
subsequently revived, whereas others were only re- 
duced to a condition of torpidity, from which there 
was revival on warming. 
I now tried the effect of artificial lowering of tem- 
perature on various plants. A plant which is very 
easily affected by cold is a certain species of Eucharis 
lily. I first obtained responses with the leaf-stalk 
of this lly at the ordinary temperature of the room 
