(11) This fine dark red and rather old leaf, though not very large,
bore an extraordinary number of tentacles (viz. 252), and behaved in an
anomalous manner. After 6 hrs. 40 m. only the short tentacles round the
outer part of the disc were inflected, forming a ring, as so often
occurs in from 8 to 24 hrs. With leaves both in water and the weaker
solutions. But after 9 hrs. [page 160] 40 m. all the outer tentacles
except twenty-five were inflected; as was the blade in a strongly
marked manner. After 24 hrs. every tentacle except one was closely
inflected, and the blade was completely doubled over. Thus the leaf
remained for two days, when it began to re-expand. I may add that the
three latter leaves (Nos. 9, 10, and 11) were still somewhat inflected
after three days. The tentacles in but few of these eleven leaves
became closelyinflected within so short a time as in the previous
experiments with stronger solutions.
We will now turn to the twenty corresponding leaves in water. Nine had
none of their outer tentacles inflected; nine others had from one to
three inflected; and these re-expanded after 8 hrs. The remaining two
leaves were moderately affected; one having six tentacles inflected in
34 m.; the other twenty-three inflected in 2 hrs. 12 m.; and both thus
remained for 24 hrs. None of these leaves had their blades inflected.
So that the contrast between the twenty leaves in water and the twenty
in the solution was very great, both within the first hour and after
from 8 to 12 hrs. had elapsed.
Of the leaves in the solution, the glands on leaf No. 1, which in 2
hrs. had all its tentacles except eight inflected, were counted and
found to be 202. Subtracting the eight, each gland could have received
only the 1/1552000 grain (.0000411 mg.) of the phosphate. Leaf No. 9
had 213 tentacles, all of which, with the exception of four, were
inflected after 24 hrs., but none of them closely; the blade was also
inflected; each gland could have received only the 1/1672000 of a
grain, or .0000387 mg. Lastly, leaf No. 11, which had after 24 hrs. all
its tentacles, except one, closely inflected, as well as the blade,
bore the unusually large number of 252 tentacles; and on the same
principle as before, each gland could have absorbed only the 1/2008000
of a grain, or .0000322 mg.
With respect to the following experiments, I must premise that the
leaves, both those placed in the solutions and in water, were taken
from plants which had been kept in a very warm greenhouse during the
winter. They were thus rendered extremely sensitive, as was shown by
water exciting them much more than in the previous experiments. Before
giving my observations, it may be well to remind the reader that,
judging from thirty-one fine leaves, the average number of tentacles is
192, and that the outer or exterior ones, the movements of which are
alone significant, are to the short ones on the disc in the proportion
of about sixteen to nine. [page 161]
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