300 PINGUICULA VULGARIS. {Cnar. XVI. 
like the helix of the human ear, to the breadth of 3; of an inch, so as 
to lie partly over the row of flies (fig. 15). The glands on which the 
flies rested, as well as those on the over-lapping margin which had 
been brought into contact with the flies, were all secreting copiously. 
Experiment 2.—A row of flies was placed on one margin of a rather 
old leaf, which lay flat on the ground; and in this case the margin, 
after the same interval as before, namely 15 hrs., had only just begun 
to curl inwards; but so much secretion had been poured forth that the 
spoon-shaped tip of the leaf was filled with it. 
Experiment 3,—Fragments of a large fly were placed close to the 
apex of a vigorous leaf, as well as along half one margin. After 4 hrs. 
20 m. there was decided incurvation, which increased a little during 
the afternoon, but was in the same state on the following morning. 
Near the apex both margins were inwardly 
curved. I have never seen a case of the apex 
itself being in the least curved towards the base 
; of the leaf. After 48 hrs. (always reckoning 
from the time when the flies were placed on the 
leaf) the margin had everywhere begun to unfold, 
Experiment 4.—A large fragment of a fly was 
placed on a leaf, in a medial line, alittle beneath 
the apex. Both lateral margins were perceptibly 
incurved in 3 hrs., and after 4 hrs. 20 m. to such 
a degree that the fragment was clasped by both 
margins. After 24 hrs. the two infolded edges 
near the apex (for the lower part of the leaf was 
not at all affected) were measured and found to 
be *11 of an inch (2°795 mm.) apart. The fly 
was now removed, and a stream of water poured 
over the leaf so as to wash the surface; and after 
Fie, 16. 24 hrs. the margins were *25 of an‘inch (67349 
(Pinguicula vulgaris.) yom.) apart, so that they were largely unfolded. 
Outline of leaf with lett After an additional 24 hrs. they were completely 
margin inflected over @ unfolded. Another fly was now put on the same 
Tow-of small fies: spot to see whether this leaf, on which the first 
fly had been left 24 hrs., would move again; 
after 10 hrs. there was a trace of incurvation, but this did not increase 
during the next 24 brs, A bit of meat was also placed on the 
margin of a leaf, which four days previously had become strongly in- 
curved over a fragment of a fly and had afterwards re-expanded ; but 
the meat did not cause even a trace of incurvation. On the contrary, 
the margin became somewhat reflexed, as if injured, and so remained 
for the three following days, as long as it was observed. 
Eaperiment 5.—A large fragment of a fly was placed halfway be- 
tween the apex and base of a leaf and halfway between the midrib and 
one margin. A short space of this margin, opposite the fly, showed a 
trace of incurvation after 3 hrs., and this became strongly pronounced in 
7 hrs. After 24 hrs. the infolded edge was only ‘16 of an inch 
