CHAPTER II.
HABITS OF WORMS _continued_.
Manner in which worms seize objects Their power of suction The instinct
of plugging up the mouths of their burrows Stones piled over the
burrows The advantages thus gained Intelligence shown by worms in their
manner of plugging up their burrows Various kinds of leaves and other
objects thus used Triangles of paper Summary of reasons for believing
that worms exhibit some intelligence Means by which they excavate their
burrows, by pushing away the earth and swallowing it Earth also swallowed
for the nutritious matter which it contains Depth to which worms burrow,
and the construction of their burrows Burrows lined with castings, and in
the upper part with leaves The lowest part paved with little stones or
seeds Manner in which the castings are ejected The collapse of old
burrows Distribution of worms Tower-like castings in Bengal Gigantic
castings on the Nilgiri Mountains Castings ejected in all countries.
IN the pots in which worms were kept, leaves were pinned down to the
soil, and at night the manner in which they were seized could be
observed. The worms always endeavoured to drag the leaves towards their
burrows; and they tore or sucked off small fragments, whenever the leaves
were sufficiently tender. They generally seized the thin edge of a leaf
with their mouths, between the projecting upper and lower lip; the thick
and strong pharynx being at the same time, as Perrier remarks, pushed
forward within their bodies, so as to afford a point of resistance for
the upper lip. In the case of broad flat objects they acted in a wholly
different manner. The pointed anterior extremity of the body, after
being brought into contact with an object of this kind, was drawn within
the adjoining rings, so that it appeared truncated and became as thick as
the rest of the body. This part could then be seen to swell a little;
and this, I believe, is due to the pharynx being pushed a little
forwards. Then by a slight withdrawal of the pharynx or by its
expansion, a vacuum was produced beneath the truncated slimy end of the
body whilst in contact with the object; and by this means the two adhered
firmly together. {53} That under these circumstances a vacuum was
produced was plainly seen on one occasion, when a large worm lying
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