only a very few tentacles were inflected over the other objects. The
bits of paper, moss, and quill were then removed from these leaves, and
bits of raw meat placed on them; and now all the tentacles were soon
energetically inflected.
Again, particles of coal-cinder (weighing rather more than the flies
used in the last experiment) were placed on the centres of three
leaves: after an interval of 19 hrs. one of the particles was tolerably
well embraced; [page 23] a second by a very few tentacles; and a third
by none. I then removed the particles from the two latter leaves, and
put on them recently killed flies. These were fairly well embraced in 7
1/2 hrs. and thoroughly after 20 1/2 hrs.; the tentacles remaining
inflected for many subsequent days. On the other hand, the one leaf
which had in the course of 19 hrs. embraced the bit of cinder
moderately well, and to which no fly was given, after an additional 33
hrs. (i.e. in 52 hrs. from the time when the cinder was put on) was
completely re-expanded and ready to act again.
From these and numerous other experiments not worth giving, it is
certain that inorganic substances, or such organic substances as are
not attacked by the secretion, act much less quickly and efficiently
than organic substances yielding soluble matter which is absorbed.
Moreover, I have met with very few exceptions to the rule, and these
exceptions apparently depended on the leaf having been too recently in
action, that the tentacles remain clasped for a much longer time over
organic bodies of the nature just specified than over those which are
not acted on by the secretion, or over inorganic objects.*
* Owing to the extraordinary belief held by M. Ziegler ( Comptes
rendus, May 1872, p. 122), that albuminous substances, if held for a
moment between the fingers, acquire the property of making the
tentacles of Drosera contract, whereas, if not thus held, they have no
such power, I tried some experiments with great care, but the results
did not confirm this belief. Red-hot cinders were taken out of the
fire, and bits of glass, cotton-thread, blotting paper and thin slices
of cork were immersed in boiling water; and particles were then placed
(every instrument with which they were touched having been previously
immersed in boiling water) on the glands of several leaves, and they
acted in exactly the same manner as other particles, which had been
purposely handled for some time. Bits of a boiled egg, cut with a knife
23