14 TRANSACTIONS OF THE (ocr. 17, 
an insect. In the foregoing experiments the slighter the irri- 
tation the slighter appeared to be the chances of closing. 
The nature of the irritating object does not appear to effect 
the rate of closing. 
3. ‘Twenty-five examples similarly irritated but with muscle 
of insect gave results similar to the foregoing ; the time of 
closing varied between 1 and 20 seconds, two did not close, ten 
interlocked. 
Continuous gentle pressure of filiaments by wisp appears to 
close the trap gently and slowly, a provision perhaps of strategic 
advantage in capturing prey. 
In these experiments was noted how variable appeared to be 
the seat of sensitiveness. In some instances a single touch of 
one of the filiaments would render closing instant ; in others all 
filiaments might be touched without causing the traps to close, 
or at the best would give rise to most tardy action. In one of 
the latter cases an accidental touch at the anterior notch in the 
line of the midrib caused rapid closing. This suggested the 
following experiments, which show that the point of closing is 
not altogether localized in and at the base of the filiaments 
(Cf. Ins. P], 294). i 
4. Ten examples were brushed by wisp along the margin 
of the face of a lobe without approaching the filiaments. Eight 
closed within 20 seconds—two of these as rapidly as if the 
filiaments had been disturbed. 
5. Ten examples were irritated by brushing the wisp sharply 
across the marginal spikes. None closed. 
6. Ten examples were stroked with wisp within the terminal 
quarter inch of the hinge. All closed within 30 seconds—three 
very rapidly. 
7. A similar experiment irritating the posterior half of the 
hinge line gave practically the same results—two closing rapidly. 
In these instances, however, it appears as in the experiments 
upon the tactile filiaments that especial interest is to be attached 
to the present condition of each leaf. 
The foregoing experiments lead to the conclusion that the 
majority of opened leaves would allow insects to pass over them 
and would not entrap unless the visitor proved a lingering one. 
It seems further evident that when a leaf has acquired or 
regained its maximum degree of sensitiveness its instant closing 
may result from irritation within the trap even when the 
filiaments may not have been touched. The insect, however, 
that passes over the trap has in general an exceedingly good 
chance of escape, even granting that the trap commences to 
close. Of a number of insects allowed to pass (slowly) over the 
