392 True . — On the Influence of Sudden Changes of 
following the transfer from o-f~2-o° C.,to i 8*5°-19*8° C. The 
time spent in the lower temperature was 94 hours. 
The striking feature of this experiment is the slight elonga- 
tion occurring promptly after the change, and the subsequent 
rapid fall of the curve. 
A measurement made at 11.25 , 1 5 minutes after the transfer 
from the cold, showed that 1 1 of the 1 6 units of elongation 
were made during the first quarter of an hour. That this is 
in part due to a turgor-change will appear from further 
considerations. 
Table XVII gives the increments of elongation shown by 
measurements made every 15 minutes seen in a root of Pisunt 
sativum under very similar circumstances. The root was 
exposed 48 hours to a temperature of o-5~o-8° C., and was then 
suddenly brought into a temperature of \ 9-4° C. 
TABLE XVII. 
Period. 
Growth in scale units. 
Temperature. 
I I.30-I I.45 
19.0 units 
19 * 5 ° c. 
II.45-I2 
5-o „ 
i 9 ’ 6 
I2-I2- 15 
4*o » 
19-6 „ 
12. 15-I2. 30 
4-o „ 
19.6 „ 
1 unit = 0.0182 mm. 
Essentially the same result is here repeated. A fuller con- 
sideration of this phenomenon is reserved for another place. 
A number of experiments were made to ascertain the effect 
of a short exposure to a low temperature. To this end the 
growth-rate at the room-temperature was first obtained, then 
the radicle was transferred to a low temperature, and the 
growth was observed for a given time. The transfer to the 
original temperature was then made, and the further growth 
noted. 
In Table XVIII is shown the record made by a root of 
Vicia Faba observed before, during and after an exposure for 
two hours to a temperature of 1-2° to 2*0° C. 
