(_Lumbricus terrestris_.)
The body of the Earth-worm is composed of a great number of narrow
rings, and along each side are four rows of very small, short,
silk-like bristles, of a substance partly horny and partly shell-like.
These bristles are placed on the edges of the rings, and it is by the
alternate contraction and expansion of these rings that the worm is
enabled to move along, the little bristles acting like hooks, and so
forming various fixed points of resistance or _fulcra_, upon which the
animal can rest at each movement forwards. The organization of the
Earth-worm is very simple, the intestinal canal for the food being a
simple straight tube, except in one part of its length, where a kind
of gizzard is found, which answers the purpose of a stomach. It is
supposed to feed upon the vegetable substances it finds in the earth.
[Illustration]
The hole, or burrow, formed in the earth by the worm, always has two
openings, one by which it enters, and by which it throws out the dirt
which is removed during the progress of its excavation, and the other
by which it sometimes leaves its burrow, so that the hole made by the
animal would be much in this form, descending at A, and reaching the
surface by B. It has been said, that the Earth-worm, if divided by the
spade or otherwise, will unite again and live; the foundation for this
appears to be the more probable fact, that, when divided, that portion
of the animal in which the head is placed may, perhaps, survive the
mutilation, and ultimately again become a perfect creature.
Although worms, after wet weather, sadly disfigure our gravel walks,
they are, at the same time, useful gardeners, loosening the earth round
the roots of plants, and thus rendering it more capable of receiving
the small fibres of the roots. During the Winter they penetrate very
deeply into the ground, and remain, according to Latreille, rolled up
in a kind of nest, protected from injury by the discharge of _mucus_,
which is furnished by the pores of their body.
The Earth-worm appears to have been a considerable favourite with
the author of the _Journal of a Naturalist_; among other remarks,
he observes, “There is another creature, and that a very important
one in the operations of nature, that is surrounded by dangers,
harassed, pursued incessantly, and becomes the prey of all; the common
Earth-worm. This animal, destined to be the natural manurer of the
soil, and the ready indicator of an approved staple, consumes on the
surface of the ground, where they soon would be injurious, the softer
parts of decayed vegetable matter, and conveys into the soil the
more woody fibres, where they moulder and become reduced to a simple
nutriment, fitting for living vegetation. The parts consumed by them
are soon returned to the surface, whence dissolved by frosts, and
scattered by rains, they circulate again in the plants of the soil,
Death still producing life.
“Thus eminently serviceable as the Worm is, it yet becomes the prey
of various orders of the animal creation, and perhaps is a solitary
example of an individual race being subjected to universal destruction.
The very emmet seizes it when disabled, and bears it away as its
prize. It constitutes throughout the year the food of many birds;
fishes devour it greedily; the hedgehog eats it; the mole pursues it
unceasingly in the pastures, along the moist bottoms of ditches, and
burrows after it through the banks of hedges, to which it retires in
dry seasons. Secured as the Worm appears to be by its residence in the
earth, from the capture of creatures inhabiting a different element,
yet many aquatic animals seem well acquainted with it, and prey on it
as a natural food, whenever it falls in their way: frogs eat it, and
even the great water-beetle I have known to seize it, when the bait of
the angler, and it has been drawn up by the hook. Yet notwithstanding
this prodigious destruction of the animal, its increase is fully
commensurate to its consumption, as if ordained the appointed food of
all.
“Worms, generally speaking, are tender creatures, and water remaining
over their haunts for a few days, drowns them. They easily become
frozen, when a mortification commences at some part, which gradually
consumes the whole substance, and we find them on the surface a mass
of jelly. Their retiring deeper into the soil is no bad indication of
approaching cold weather; but no sooner is the frost out of the ground,
than they approach the surface.
“Earth-worms do considerable mischief to the floriculturist by drawing
the young plants, immediately after they are transplanted, into
the earth. In the drainage of lands they are of essential service,
penetrating the clay that lies beneath the vegetable mould in every
direction, and thus forming numerous small canals to carry off the
water into the deep trenches dug by the agriculturist.” The author we
have already quoted, after concluding this account of the Worm, says,
“I would advocate the cause of all creatures, had I the privilege of
knowing the excellency of them; not willingly assigning vague and
fanciful claims to excite wonder, or manifesting a base pride by any
vaunt of superior observation; but when we see, blind as we are, that
all things are formed in justice, mercy, truth, I would tell my tale
as a man, glory as a Christian, and bless the gracious Power that
permitted me to obtain this knowledge.”