24 DROSERA ROTUNDIFOLIA. Cuar. IL 
The Inflection of the Exterior Tentacles as directly caused 
by Objects left in Contact with their Glands. 
I made a vast number of trials by placing, by means 
of a fine needle moistened with distilled water, and 
with the aid of a lens, particles of various substances 
on the viscid secretion surrounding the glands of the 
outer tentacles. I experimented on both the oval and 
long-headed glands. When a particle is thus placed 
on a single gland, the movement of the tentacle is 
particularly well seen in contrast with the stationary 
condition of the surrounding tentacles. (See previous 
fig. 6.) In four cases small particles of raw meat 
caused the tentacles to be greatly inflected in between 
5 and 6 m. Another tentacle similarly treated, 
and observed with special care, distinctly, though 
slightly, changed its position in 10 s. (seconds); and 
this is the quickest movement seen by me. In 2m. 
30s. it had moved through an angle of about 45°. 
The movement as seen through a lens resembled that 
of the hand of a large clock. In 5m. it had moved 
through 90°, and when I looked again after 10 m, 
the particle had reached the centre of the leaf; so 
that the whole movement was completed in less 
them, but this produced no effect. cause inflection. M. Ziegler 
I may here add, as showing that 
the leaves are not acted on by the 
odour of nitrogenous substances, 
that pieces of raw meat stuck on 
needles were fixed as close as 
possible, without actual contact, 
to several leaves, but produced 
no effect whatever. On the other 
hand, as we shall hereafter see, 
the vapours of certain volatile 
substances and fluias, such as of 
carbonate of ammonia, chloro- 
form, certain essential oil2, &c., 
makes still more extraordinary 
statements with respect to the 
power of animal substances, which 
have been left close to, but: not in 
contact with, sulphate of quinine. 
The action of salts of quinine will 
be described in a future chapter. 
Since the appearance of the paper 
above referred to, M. Ziegler has 
published a book on the same 
subject, entitled, ‘Atonicité of 
Zoicité,” 1874. 
