248 DIONÆA MUSCIPULA. (Omir. XMI 
case a leaf re-expanded to about two-thirds of the full extent 
in 7 hrs., and completely in 32 lrs.; but one of its filaments 
had been touched merely with a hair just enough to cause 
the leaf to close. Of these ten leaves only a few re-expanded 
completely in less than two days, and two or three required 
even a little longer time. Before, however, they fully 
re-expand, they are ready to close 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, 
Ido 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, gelatine, casein, 
and, no doubt, any other substance containing 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 projection on the outside of the 
leaf is distinctly visible. When the two lobes are thus 
completely shnt, they resist being opened, as by a thin 
wedge being driven between them, with astonishing force, 
and are generally ruptured rather than yield. If not 
ruptured, they close again, as Dr. Canby informs me in a 
letter, “ with quite a loud flap.” But if the end ofa leaf is 
held firmly between the thumb and finger, or by a clip, so 
* According to Dr. Curtis, in ‘ Boston Journal of Nat. Hist.’ vol. i. 1837, 
p: 123. 
a scent 
