Cuar. XII MANNER OF CAPTURING INSECTS. 307 
instantly if their sensitive filaments are touched. 
How many times a leaf is capable of shutting and 
opening if no animal matter is left enclosed, I do 
not know; but one leaf was made to close four times, 
reopening afterwards, within six days. On the last 
occasion it caught a fly, and then remained closed for 
many days. 
This power of reopening quickly after the filaments 
have been accidentally touched by blades of grass, 
or by objects blown on the leaf by the wind, as 
occasionally happens in its native place,* must be of 
some importance to the plant; for as long as a 
leaf remains closed, it cannot of course capture an 
insect. 
When the filaments are irritated and a leaf is made 
to shut over an insect, a bit of meat, albumen, gela- 
tine, casein, and, no doubt, any other substance con- 
taining soluble nitrogenous matter, the lobes, instead 
of remaining concave, thus including a concavity, 
slowly press closely together throughout their whole 
breadth. As this takes place, the margins gradually 
become a little everted, so that the spikes, which at first 
intercrossed, at last project in two parallel rows. The 
lobes press against each other with such force that I 
have seen a cube of albumen much flattened, with 
distinct impressions of the little prominent glands; but 
this latter circumstance may have been partly caused 
by the corroding action of the secretion. So firmly do 
they become pressed together that, if any large insect 
or other object has been caught, a corresponding pro- 
jection on the outside of the leaf is distinctly visible, 
When the two lobes are thus completely shut, they 
* According to Dr. Curtis, in ‘Boston Journal of Nat. Hist. 
vol. i. 1837, p. 123. 
