THE TEMPERATURE OF PLANTS. 575 
experiment was abandoned. The following are the maximum 
readings of the three thermometers for the period mentioned. 
Day. Soil. Nut. eee Day. Soil. Nut. aes 
Fah. Fah. Fah. Fah. Fah. Fah. 
19 50:2 50°9 70:2 33 54°] 62°0 76°4 
20 50'2 50°9 68:0 34 54:1 63°6 (BSA 
21 50°3 51°4 69°8 35 54°6 65°1 W714 
22 51:0 51°8 FUE 36 54°1 66°5 71:9 
23 51°1 Vee 69°4 37 54°1 69°1 70°1 
24 51°4 52°8 74:1 38 54°6 71°4 75°3 
25 51°4 53°7 74°4 39 54°7 73:0 se 
26 52°0 54°4 68°8 40 54°9 76°1 Took 
27 S221 56°0 Ziel 4] 54°9 Nez 71:0 
28 52°6 56°9 76°6 42 55°4 Hers How 
29 53°3 580 76°0 43 56°4 79'8 72°6 
30 53°3 58°6 74:4 44 56'1 81:0 74:4 
31 53°6 59°7 70°3 45 56°6 81°6 70°1 
32 54°0 60°6 79:0 46 56°6 83°0 70°6 
It is to be regretted that the experiment ended here, but cireum- 
stances prevented further investigation at that time. Numerous 
other interesting data could be given which might be worth 
recording, but enough has been said to induce some one to still 
further carry out experiments with regard to the generaticn of 
heat in plants. Science has recently offered to investigators 
“Electro thermo. needles,” which should be of immense assistance 
in determining temperatures much more minutely. The instru- 
ments used by the writer in his researches were, in several instances, 
very inferior to those now procurable. Still the data secured are, 
in the main, reliable, as the instruments used were tested by a 
Kew standard thermometer, and corrected accordingly. 
No. 17.—ON THE GROWTH OF VEGETAL GALLS. 
By W. W. Froaeart. 
(Read Saturday, January 8, 1898.) 
