Chap. II. INFLECTION INDIRECTLY CAUSED. 23 



a second by a very few tentacles ; and a tliird by none. 

 I then removed the particles from the two latter leaves, 

 and put on them recently killed flies. iThese were 

 fairly well embraced in 7 J hrs. and thoroughly after 

 20 J 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 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.* 



* Owinj? to the extraordinary and particles were then placed 

 belief held by M. Zieglcr (' Comp- (every iustriiment with which 

 tes rendus,' May 1872, p. 122), they were touched havincf been 

 that albuminous substances, if previously immersed in boiling 

 held for a moment between the water) on the glands of several 

 fingers, acquire the property of leaves, and they acted in exactly 

 making the tentacles of Drosera the same manner as other par- 

 contract, whereas, if not thus held, tides, which had been purposely 

 they have no such power, I tried handled for some time. Bits of 

 some experiments with great care, a boiled egg, cut with a knife 

 but the results did not confirrn which had been washed in boiling 

 this belief. Eed-hot cinders were water, also acted like any other 

 taken out of the fire, and bits animal substance. I breathed on 

 of glass, cotton-thread, blotting some leaves for above a minute, 

 paper and thin slices of cork and repeated the act two or three 

 were immersed in boiling water ; times, with my mouth close to 



