422 Stiles and j0rgensen . — Studies in Permeability. V. 
ment in four different thermostats. The swelling of potato at io° C., 20° C., 
30° C., and 40° C. measured in this way is shown in Table IV. 
Table IV. 
Swelling of Potato in Distilled Water at Different Temperatures. 
10 ° c . 
20 
0 C . 
3°° C . 
O 
0 
.O 
Time. 
Swelling. 
Time. 
Swelling. 
Time. 
Swelling. 
Time. Swelling. 
hrs. 
per cent. 
hrs. 
per cent. 
hrs. 
per cent. 
hrs. 
per cent. 
0-65 
5-6 
o*53 
9* 1 
o-6o 
19*6 
1.23 
4.4 
1.27 
8.7 
1-28 
12-6 
1.30 
14-4 
!’95 
5*8 
2*00 
10*2 
2*00 
15* 1 
2*02 
10.3 
2-85 
7*2 
2*87 
II- 8 
2-87 
17.7 
2*87 
5-8 
4-98 
8*9 
5*03 
14-5 
5-05 
2 06 
08 
-5*8 
6*57 
io-3 
665 
16-2 
6*67 
22.5 
6-o8 
-8.2 
18-80 
19*8 
19.23 
20-6 
19-68 
— 14*6 
These results are shown graphically in Fig. 4. They clearly illustrate 
the fact that the temperature exerts a marked influence on the rate of 
water absorption by potato tissue — the 
higher the temperature the more rapid 
the swelling. With higher tempera- 
tures, however, secondary actions occur 
which transform the swelling into a 
rapid shrinkage. Measurements were 
not taken at temperatures higher than 
40° C., but the results obtained leave 
little doubt that the initial period of 
swelling would be less at higher tem- 
peratures, and the shrinkage still more 
rapid. The results are analogous 
to those obtained by F. F. Blackman 
for carbon assimilation, where assimi- 
lation falls off with time at higher tem- 
peratures owing to secondary actions. 
The influence of temperature on the swelling of carrot is similar to its 
influence on potato, although it is not so marked. The numbers obtained 
by experiments are given in Table V. 
Table V. 
Swelling of Carrot in Distilled Water at Different Temperatures. 
io° C . 
20° c . 
3°° C . 
40 
0 C . 
Time. 
Swelling. 
Time. Swelling. 
Time. Swelling. 
Time. 
Swelling. 
hrs. 
per cent. 
hrs. per cent. 
hrs. per cent, 
hrs. 
per cent. 
0-63 
9’4 
0-52 io-8 
0*52 12-6 
0-58 
12-0 
2-27 
15.2 
2*28 16-0 
2-28 16-5 
2-35 
10.9 
3*13 
16-6 
3.15 17.2 
3*13 17-3 
3.22 
8-8 
14.90 
20*1 
15-13 18-8 
15-08 16-6 
15*23 
-i-7 
There will again be observed the increase in the rate of swelling with 
Fig. 4. Curves illustrating the influence 
of temperature on the swelling of potato in 
distilled water. 
