298 DIONZA MUSCIPULA. Cuap. XIIL 
the surface of the leaf much more sensitive to a touch 
than it is in its ordinary state; and this is a curious 
fact. Two days afterwards the end of the leaf where 
nothing had been placed began to open, and on the 
third day was much more open than the opposite end 
where the albumen had lain. 
Lastly, large drops of a solution of one part of car- 
bonate of ammonia to 146 of water were placed on 
some leaves, but no immediate movement ensued. I 
did not then know of the slow movement caused by 
animal matter, otherwise I should have observed the 
leaves for a longer time, and they would probably 
have been found closed, though the solution (judging 
from Drosera) was, perhaps, too strong. 
From the foregoing cases it is certain that bits of 
meat and albumen, if at all damp, excite not only the 
glands to secrete, but the lobes to close. This move- 
ment is widely different from the rapid closure caused 
by one of the filaments being touched. We shall see 
its importance when we treat of the manner in which 
insects are captured. There is a great contrast be- 
tween Drosera and Dionza in the effects produced by 
mechanical irritation on the one hand, and the absorp- 
tion of animal matter on the other. Particles of glass 
placed on the glands of the exterior tentacles of Dro- 
sera excite movement within nearly the same time, 
as do particles of meat, the latter being rather the 
most efficient ; but when the glands of the disc have 
bits of meat given them, they transmit a motor impulse 
to the exterior tentacles much more quickly than do 
these glands when bearing inorganic particles, or 
when irritated by repeated touches.” On the other 
hand, with Dionea, touching the filaments excites 
incomparably quicker movement than the absorption 
of animal matter by the glands. Nevertheless, in 
