usual habit of avoiding the foot-stalk.
On the gravel-walks in my garden a very large number of leaves of three
species of Pinus (_P. austriaca_, _nigricans_ and _sylvestris_) are
regularly drawn into the mouths of worm burrows. These leaves consist of
two so-called needles, which are of considerable length in the two first
and short in the last named species, and are united to a common base; and
it is by this part that they are almost invariably drawn into the
burrows. I have seen only two or at most three exceptions to this rule
with worms in a state of nature. As the sharply pointed needles diverge
a little, and as several leaves are drawn into the same burrow, each tuft
forms a perfect _chevaux de frise_. On two occasions many of these tufts
were pulled up in the evening, but by the following morning fresh leaves
had been pulled in, and the burrows were again well protected. These
leaves could not be dragged into the burrows to any depth, except by
their bases, as a worm cannot seize hold of the two needles at the same
time, and if one alone were seized by the apex, the other would be
pressed against the ground and would resist the entry of the seized one.
This was manifest in the above mentioned two or three exceptional cases.
In order, therefore, that worms should do their work well, they must drag
pine-leaves into their burrows by their bases, where the two needles are
conjoined. But how they are guided in this work is a perplexing
question.
This difficulty led my son Francis and myself to observe worms in
confinement during several nights by the aid of a dim light, while they
dragged the leaves of the above named pines into their burrows. They
moved the anterior extremities of their bodies about the leaves, and on
several occasions when they touched the sharp end of a needle they
withdrew suddenly as if pricked. But I doubt whether they were hurt, for
they are indifferent to very sharp objects, and will swallow even
rose-thorns and small splinters of glass. It may also be doubted,
whether the sharp ends of the needles serve to tell them that this is the
wrong end to seize; for the points were cut off many leaves for a length
of about one inch, and fifty-seven of them thus treated were drawn into
the burrows by their bases, and not one by the cut-off ends. The worms
in confinement often seized the needles near the middle and drew them
towards the mouths of their burrows; and one worm tried in a senseless
manner to drag them into the burrow by bending them. They sometimes
collected many more leaves over the mouths of their burrows (as in the
34