Measurement of Rale of Shrinkage of Turgid Tissues . I. 299 
Fig. 12. Curve showing the rates of shrinkage of tissue of onion leaf under uniform external 
osmotic compression but at different temperatures. This curve exhibits the alteration of protoplasmic 
permeability brought about by temperature. The actual ordinates are the values of the tangents of 
the shrinkage curves where the 50 % shrinkage line cuts them in series. 
Table II. 
Temperature. 
Observed contraction 
Time taken to 
in scale divisions. 
complete contraction , 
Min. 
5° C. 
19 
95 
i 4 ° C. 
2 o °5 
85 
1 9 0 C. 
41 
100 
26° C. 
4 2 '5 
100 
30° C. 
34 
35 
35° C. 
36-5 
25 
37° C. 
20*8 
1 2 
S 8 ° C. 
33 
10 
*42° C. 
28 
10 
