62 RESPONSE IN THE LIVING AND NON-LIVING 
temperature 0° C., for twenty-four hours, and afterwards 
took their records once more at the ordinary tempera- 
ture of the room. From these it will be seen that 
while the responsiveness of Eucharis lily, known to be 
susceptible to the effect of cold, had entirely disappeared, 
that of the hardier plants, Holly and Ivy, showed very 
little change (fig. 36). 
Another very curious effect that I have noticed is 
that when a plant approaches its death-point by reason 
of excessively high or low temperature, not only is its 
general responsiveness diminished almost to zero, but 
even the slight response occasionally becomes reversed. 
aL 
a 
\ LAO b 
} KGS x 
Holly Eucharis 
Fic. 36.—ArrreR-EFFECT OF Comp on Ivy, Houtiy, ann Evcuaris Liny 
a. The normal response; 0. Response after subjection to freezing temperature for 
twenty-four hours, 
Influence of high temperature, and determination of 
death-point.—I next tried to find out whether a rise of 
temperature produced a depression of response, and 
whether the response disappeared at a maximum tem- 
perature—the temperature of death-point. For this 
purpose I took a batch of six radishes. and obtained 
from them responses at gradually increasing tempera- 
tures. These specimens were obtained late in the 
season, and their electric responsiveness was much 
lower than those obtained earher. The plant, previously 
kept for five minutes in water at a definite temperature 
