66 DROSERA ROTUNDIFOLIA. Cuap JV, 
CHAPTER IV. 
Tur Erreots or Heat on THE LEAVES. 
Nature of the experiments — Effects of boiling water — Warm water 
causes rapid inflection — Water at a higher temperature does not 
cause immediate inflection, but does not kill the leaves, as shown 
by their subsequent re-expansion and by the aggregation of the 
protoplasm —A still higher temperature kills the leaves and 
coagulates the albuminous contents of the glands. 
In my observations on Drosera rotundifolia, the leaves 
seemed to be more quickly inflected over animal sub- 
stances, and to remain inflected for a longer period 
during very warm than during cold weather. I 
wished, therefore, to ascertain whether heat alone 
would induce inflection, and what temperature was 
the most efficient. Another interesting point pre- 
sented itself, namely, at what degree life was extin- 
guished ; for Drosera offers unusual facilities in this 
respect, not in the loss of the power of inflection, but 
in that of subsequent re-expansion, and more espe- 
cially in the failure of the protoplasm to become 
aggregated, when the leaves after being heated are 
immersed in a solution of carbonate of ammonia.* 
* When my experiments on the 
cludes that the protoplasm with- 
effects of heat were nade, I was 
in their cells always coagulates, 
not aware that the subject had 
been carefully investigated by 
several observers. For instance, 
Sachs is convinced (‘Traité de 
Botanique, 1874, pp. 772, 554) 
that the most different kinds of 
plants all perish if kept for 10 m. 
in water at 45° to 46° Cent., or 
113° to 115° Fahr.; and he con- 
if in a damp condition, at a tem- 
perature of between 50° and 60° 
Cent., or 122° to 140° Fahr. Max 
Schultze and Kiihne (as quoted 
by Dr. Bastian in ‘Contemp. 
Review, 1874, p. 528) “found 
that the protoplasm of plant- 
cells, with which they experi- 
mented, was always killed and 
