Cur. II,  INFLECTION INDIRECTLY CAUSED. 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 73 hrs. and thoroughly after 
203 hrs.; the tentacles reinaining 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 excep- 
tions 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 bv M. Ziegler (‘Comp- 
tes 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 immerse:l in boiling water; 
3 
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 par- 
ticles, 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 
