aap, I  INFLECTION INDIRECTLY CAUSED. 29 
in an efficient state, for after 24 hrs. had elapsed, they 
were tried with bits of meat, and all became quickly 
inflected. It then occurred to me that particles float- 
ing on the secretion would cast shadows on the glands, 
which might be sensitive to the interception of the 
light. Although this seemed highly improbable, as 
“minute and thin splinters of colourless glass acted 
powerfully, nevertheless, after it was dark, I put on, 
by the aid of a single tallow candle, as quickly as 
possible, particles of cork and glass on the glands of a 
dozen tentacles, as well as some of meat on other 
glands, and covered them up so that not a ray of light 
could enter ; but by the next morning, after an interval 
of 13 hrs., all the particles were carried to the centres 
of the leaves. 
These negative results led me to try many more 
experiments, by placing particles on the surface of the 
drops of secretion, observing, as carefully as I could, 
whether they penetrated it and touched the surface of 
the glands. The secretion, from its weight, generally 
forms a thicker layer on the under than on the upper 
sides of the glauds, whatever may be the position of 
the tentacles. Minute bits of dry cork, thread, blotting 
paper, and coal cinders were’ tried, such as those pre- 
viously employed; and I now observed that they 
absorbed much more of the secretion, in the course of 
a few minutes, than I should have thought possible ; and 
as they had been laid on the upper surface of the secre- 
tion, where it is thinnest, they were often drawn down, 
after a time, into contact with at least some one point 
of the gland. With respect to the minute splinters 
of glass and particles of hair, I observed that the 
secretion slowly spread itself a little over their sur- 
faces, by which means they were likewise drawn down- 
wards or sideways, and thus one end, or some minute 
. 
