[Experiment 1.—A leaf was plunged, and as in all cases waved about for
a few minutes, in water at 130° (54°.4 Cent.), but there was no trace
of inflection; it was then placed in cold water, and after an interval
of 15 m. very slow movement was [page 70] distinctly seen in a small
mass of protoplasm in one of the cells of a tentacle.* After a few
hours all the tentacles and the blade became inflected.
Experiment 2.—Another leaf was plunged into water at 130o to 131o, and
as before there was no inflection. After being kept in cold water for
an hour, it was placed in the strong solution of ammonia, and in the
course of 55 m. the tentacles were considerably inflected. The glands,
which before had been rendered of a brighter red, were now blackened.
The protoplasm in the cells of the tentacles was distinctly aggregated;
but the spheres were much smaller than those generated in unheated
leaves when subjected to carbonate of ammonia. After an additional 2
hrs. all the tentacles, excepting six or seven, were closely inflected.
Experiment 3.—A similar experiment to the last, with exactly the same
results.
Experiment 4.—A fine leaf was placed in water at 100° (37°.7 Cent.),
which was then raised to 145° (62°.7 Cent.). Soon after immersion,
there was, as might have been expected, strong inflection. The leaf was
now removed and left in cold water; but from having been exposed to so
high a temperature, it never re-expanded.
Experiment 5.—Leaf immersed at 130° (54°.4 Cent.), and the water raised
to 145° (62°.7 Cent.), there was no immediate inflection; it was then
placed in cold water, and after 1 hr. 20 m. some of the tentacles on
one side became inflected. This leaf was now placed in the strong
solution, and in 40 m. all the submarginal tentacles were well
inflected, and the glands blackened. After an additional interval of 2
hrs. 45 m. all the tentacles, except eight or ten, were closely
inflected, with their cells exhibiting a slight degree of aggregation;
but the spheres of protoplasm were very small, and the cells of the
exterior tentacles contained some pulpy or disintegrated brownish
matter.
Experiments 6 and 7.—Two leaves were plunged in water at 135° (57°.2
Cent.) which was raised to 145° (62°.7 Cent.); neither became
inflected. One of these, however, after having been left for 31 m. in
cold water, exhibited some slight inflection, which increased after an
additional interval of 1 hr. 45 m., until
* Sachs states (‘Traité de Botanique,’ 1874, p. 855) that the movements
of the protoplasm in the hairs of a Cucurbita ceased after they were
exposed for 1 m. in water to a temperature of 47° to 48° Cent., or 117°
to 119° Fahr. [page 71]