or by the middle. This alone is almost sufficient to show that chance
does not determine the manner in which leaves are dragged into the
burrows.
Of the above 227 leaves, 70 consisted of the fallen leaves of the common
lime-tree, which is almost certainly not a native of England. These
leaves are much acuminated towards the tip, and are very broad at the
base with a well-developed foot-stalk. They are thin and quite flexible
when half-withered. Of the 70, 79 per cent. had been drawn in by or near
the tip; 4 per cent. by or near the base; and 17 per cent. transversely
or by the middle. These proportions agree very closely, as far as the
tip is concerned, with those before given. But the percentage drawn in
by the base is smaller, which may be attributed to the breadth of the
basal part of the blade. We here, also, see that the presence of a
foot-stalk, which it might have been expected would have tempted the
worms as a convenient handle, has little or no influence in determining
the manner in which lime leaves are dragged into the burrows. The
considerable proportion, viz., 17 per cent., drawn in more or less
transversely depends no doubt on the flexibility of these half-decayed
leaves. The fact of so many having been drawn in by the middle, and of
some few having been drawn in by the base, renders it improbable that the
worms first tried to draw in most of the leaves by one or both of these
methods, and that they afterwards drew in 79 per cent. by their tips; for
it is clear that they would not have failed in drawing them in by the
base or middle.
The leaves of a foreign plant were next searched for, the blades of which
were not more pointed towards the apex than towards the base. This
proved to be the case with those of a laburnum (a hybrid between _Cytisus
alpinus_ and _laburnum_) for on doubling the terminal over the basal
half, they generally fitted exactly; and when there was any difference,
the basal half was a little the narrower. It might, therefore, have been
expected that an almost equal number of these leaves would have been
drawn in by the tip and base, or a slight excess in favour of the latter.
But of 73 leaves (not included in the first lot of 227) pulled out of
worm-burrows, 63 per cent. had been drawn in by the tip; 27 per cent. by
the base, and 10 per cent. transversely. We here see that a far larger
proportion, viz., 27 per cent. were drawn in by the base than in the case
of lime leaves, the blades of which are very broad at the base, and of
which only 4 per cent. had thus been drawn in. We may perhaps account
32