PLANT RESPONSE 65 
least, recovery was quicker. At 20° C., for example, 
the response was 21 dns., and the recovery was not com- 
plete in the course of a minute. At 30° C., however, 
the response had been reduced to 7:5 divisions, but 
there was almost complete recovery in twelve seconds. 
As the temperature was gradually increased, a con- 
tinuous decrease of response occurred. This diminution 
of response with increased temperature appears to be 
universal, but the quickening of recovery may be true 
of individual cases only. 
TABLE SHOWING DIMINUTION OF RESPONSE WITH INCREASING 
TEMPFPRATURE 
(‘01 Volt = 35 divisions) 
Temperature Response Temperature Response 
ee 21 | SO aan Aaa 
2) ee 75 | GO ences 3 
AN Soar 5:5 
In radishes response disappeared completely at 
55° C,, but with celery, heated in the manner described, 
I could not obtain its entire abolition at 60° C. or even 
higher. <A noticeable circumstance, however, was the 
prolongation of the period of recovery at these high 
temperatures. I soon understood the reason of this 
apparent anomaly. The method adopted in the present 
case was that of dry heating, whereas the previous ex- 
periments had been carried on by the use of hot water. 
It is well known that one can stand a temperature of 
100° C. without ill effects in the hot-air chamber of a 
Turkish bath, while immersion in water at 100° C. would 
be fatal. 
In order to find out whether subjection to hot water 
would kill the celery-stalk, I took it out and placed it 
: 
