EUPHORBIA VI ROSA AND ALOE DICHOTOMA 53 
The thermometers W and T are here inserted in the same unwounded 
branch, W being 70 cm. above T. Assuming that the fall in the unwounded 
stem is sympathetic to that in the wounded stem, some influence must be 
transmitted through the plant from P to W. This influence must pass the 
bulb of the thermometer T before it reaches W. But W reacts more quickly 
than T and also undergoes a greater fall of temperature. On the hypothesis 
outlined above it is difficult to explain this except on the assumption that 
the walls of the pith cavity m which the bulb of T is enclosed were unusually 
rigid or, more probably, suffered less exhaustion of the fluids of their latex- 
system. 
CHART IV. December 14. 
Euphorbia A (Thermometers W, T , P). 
The sun became slightly obscured during the early part of this experiment, 
and this no doubt added to the amount of the fall in each case. The recovery 
of P commenced 11 minutes and those of W and T 6 minutes before the 
clouds dispersed. 
No. 4. December 14. 
Plant. Euphorbia A. 
Thermometers. W, T, P all in same positions as in Experiment 3. 
Immediately after the 1 o’clock reading, all 5 furrows above and below 
the insertion of the thermometer W were wounded over an area extending 
