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
which had been washed in boiling water, also acted like any other
animal substance. I breathed on some leaves for above a minute, and
repeated the act two or three times, with my mouth close to [[page 24]]
them, but this produced no effect. I may here add, as showing that the