had never been disturbed, a worm was cut into two at 55 inches, and
another was found here at Down in December at the bottom of its burrow,
at 61 inches beneath the surface. Lastly, in earth near an old Roman
Villa, which had not been disturbed for many centuries, a worm was met
with at a depth of 66 inches; and this was in the middle of August.
The burrows run down perpendicularly, or more commonly a little
obliquely. They are said sometimes to branch, but as far as I have seen
this does not occur, except in recently dug ground and near the surface.
They are generally, or as I believe invariably, lined with a thin layer
of fine, dark-coloured earth voided by the worms; so that they must at
first be made a little wider than their ultimate diameter. I have seen
several burrows in undisturbed sand thus lined at a depth of 4 ft. 6 in.;
and others close to the surface thus lined in recently dug ground. The
walls of fresh burrows are often dotted with little globular pellets of
voided earth, still soft and viscid; and these, as it appears, are spread
out on all sides by the worm as it travels up or down its burrow. The
lining thus formed becomes very compact and smooth when nearly dry, and
closely fits the worm s body. The minute reflexed bristles which project
in rows on all sides from the body, thus have excellent points of
support; and the burrow is rendered well adapted for the rapid movement
of the animal. The lining appears also to strengthen the walls, and
perhaps saves the worm s body from being scratched. I think so because
several burrows which passed through a layer of sifted coal-cinders,
spread over turf to a thickness of 11 2 inch, had been thus lined to an
unusual thickness. In this case the worms, judging from the castings,
had pushed the cinders away on all sides and had not swallowed any of
them. In another place, burrows similarly lined, passed through a layer
of coarse coal-cinders, 31 2 inches in thickness. We thus see that the
burrows are not mere excavations, but may rather be compared with tunnels
lined with cement.
The mouths of the burrow are in addition often lined with leaves; and
this is an instinct distinct from that of plugging them up, and does not
appear to have been hitherto noticed. Many leaves of the Scotch-fir or
pine (_Pinus sylvestris_) were given to worms kept in confinement in two
pots; and when after several weeks the earth was carefully broken up, the
upper parts of three oblique burrows were found surrounded for lengths of
7, 4, and 31 2 inches with pine-leaves, together with fragments of other
leaves which had been given the worms as food. Glass beads and bits of
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