The Sun.
London, England, 1829-07-17 00:00:00

THE AVRILL, OR WOODWORM.

Resting myself one excessively warm day on
a projecting block of moor-stone rock on the
shore of the Rideau Lake, I took a large clam
shell that was lying beside me bleaching in the
sun, and pitched it into the pellucid waters. My
eye followed it as it sunk zig-zag fashion to the
bottom, which seemed to be about twenty feet
down ; but on trying it with our sounding ap-
paratus it astonished me to find the depth forty-
two feet. How much deeper the eye could have
pursued the object there is no saying, as it
seemed to increase in size the deeper it went.
While pondering on this matter one of our Ca-
nadian party brought me a large black worm out
of the wood in the hollow of his hand ; the same

I had often seen before, but never having had
leisure to examine him minutely I now set about
that very important matter. He was four inches
and a quarter long, one quarter of an inch in
thickness, had sixteen legs on each side of his
belly, making in all thirty-two ; the body was
of one thickness from end to end. The tail
and head were rounded in the same manner only
in the head there seemed to be a mouth, wimble-
shaped—no doubt set round with cutting edges,
if a microscope were brought to assist the vision,
as it can bore holes into trees that are in a cer-
tain state of decay as neatly as any gimlet, hence
its French name of avrill. On minute exami-
nation we also found that it had eight vertebral,
or divisions, with four legs to each. The trees
which this singular animal seems to admire are
those which have been deprived of their bark by
age ; it crawls into them first at some crack, or
at a hole from which a knot has fallen out ; for
be it known that when a tree gets shrunk from
the want of sap the knots, being of a hard sub-
stance, do not shrink so much, but generally
either drop out, and leave a hole behind them,
or a vacant space partly round between them and
the tree ; the reverse being the case when it is
young and growing, the knots are then formed
by being acted upon by the pressure of timber
that keeps swelling about them. Once in this
strange worm keeps boring holes to the outer
rind, and through it ; for, although the tree
has no bark, a hard casement encloses the rotten
interior. Now, this would seem to be done
for the purpose of introducing moisture, and
promoting the decomposition, as nature seems
as anxious to encourage decay as growth, and
this certainly, does it. A capillary action is
brought about by these worms, and moisture
conducted through the tree. Were no holes
made the casement alluded to would remain for
many years, being rendered almost as hard as
stone, by the dry weather and heat of the sun.
This worm and the woodpecker are never at
work on the same tree ; the season for the bird
is before the bark falls off, which it greatly pro-
motes ; that of the worm after.
The movements of this worm are not very
quick ; when laid down on a warm horizontal
rock it travelled about at a yard in a minute.
One of the Canadians, unknown to me, took it
up and threw it a little way into the lake, where
the water was about ten feet deep. This rather
displeased me ; the poor fellow, seeing this, was
as sorry as myself; so we went down on the
lower ledge of the rock, and, what was to me
extremely curious, we beheld the avrill crawling
slowly on the bottom beneath the deep water. In
about five minutes time it reached the bottom of
the rock, and continued very slowly to clamber
up to the surface, in doing which it seemed to
have great difficulty, and was frequently about
to relinquish its hold, and fall again to the
bottom. Had the lake at this time been the
least agitated it would not have succeeded in
ascending the face of the rock. At length it
came ont very much exhausted, having been be-
neath the water about twenty minutes. How
it can live in such a situation so long I leave it
to anatomists to judge ; and how it knew the
way direct towards the shore, instead of steering
its course farther out, is also a mystery. It must
have seen the rock rising up from the water, or
the small declivity of the beach might have given
it some information as to this. I am thus minute,
for worms and their ways are things not suf-
ficiently attended to by us, although they get our
bodies to themselves at last. The manner in
which they work out their holes is very
curious ; the borings are passed beneath the
belly, in a hollow between the rows of legs. These,
being strong, move about the dust of the rotten
wood. The hollow is not unlike the groove of
a gimlet. In Plymouth Sound there is a ma-
rine worm, about three-quarters of an inch thick,
and about the same length as the avrill, which
bores holes through the limestone rocks in the
bottom of the Sound, where the salt water
is from forty to twenty feet deep. I have seen
many of these stones so bored, that when inspect-
ing the bottom with a diving-bell for a good
foundation to a sea-wall that was about to be
erected we found acres of it bored as with a
wimble to a considerable depth ; even many of
the limestone blocks that compose the break-
water in the Sound are bored like a sieve, and
actually devoured by this worm. It succeeds in
making these holes by putting a quantity of sand
before its head, When it works away like a mar-
ble cutter, making a circular aperture. It may
not be proper, perhaps, to say that this worm
will gnaw the breakwater so that the damages
may take some cash to repair; this work keeps
sinking every year ; perhaps it may be mainly
attributed to that cause.
Thus do we see very insignificant animals
perform wonders. The interminable forests of
America are cleared of their dead timber by a
worm that grinds its hard particles, when the
friability of the substance absorbs moisture, and
decomposition rapidly ensues. We observe the
bottom of the ocean changed in a strange man-
ner, and the hard rocks reduced to powder ; the
sand, in due time, after shifting about from one
coast to another, becomes consolidated again
somewhere else by meeting with minerals of a
plastic composition. In short, look where we
will, the constant transition of nature is suffi-
ciently obvious.—Mactaggares Canada.