66 RESPONSE IN THE LIVING AND NON-LIVING 
for five minutesin water at 55° C. This, as will be seen 
from the record taken afterwards, effectively killed the 
plant (fig. 38, w). 
Increased sensitiveness as after-effect of temperature 
variation.—A very curious effect of temperature varia- 
tion is the marked increase of sensitiveness which often 
30°C 
i 50 C 
25:6 a 
~«<— Temperature 
falling 
° 
I9 Cc 
° 
BOEG 
ie 50 C 70°C 
Temperature TUS g —> 
Fic. 39.--Errect oF Risinc AND FaLuinc TEMPERATURE ON THE RESPONSE 
oF Scorcu Kae 
appears as its after-effect. I noticed this first in a series 
of observations where records were taken during the 
rise of temperature and continued while the tempera- 
ture was falling (fig. 39). The temperature was 
adjusted by electric heating. It was found that the 
responses were markedly enhanced during cooling, as 
