The Yakima herald. [volume] (North Yakima, W.T. [Wash.]) 1889-1914, 1896-07-30
ONLY EARTHWORMs.
YET THEY HAVE CUT QUITE A fig
uRe IN THE WORLDS HISTORY.

AhH W oHAAh No. k$o A-It. oao E$o 6tM1E u
Hearing, but IL Sensitive TO Strong Light
and vibrations Of sound-0hjects Of An
tiquisy Preserved by Earthworms.
The common earthworm. despised by
man and heedlessly trodden underfoot,
fulfills part In nature that would seem
incredible but for the facts revealed by
the patient and long continued researches
of Darwin. Worms" says Darwin,
''have played more important part in
the history of the world than most per-
sons would at first suppose. Let MS
follow Darwin and see how this appar-
emily insignificant creature has changed
the face of nature We will first consider
the habits and mode Of life Of the earth
worm. As every one knows. the worms
live in burrows in the superficial layer
of the ground. They can live anywhere
in layer of earth. provided it retains
moisture, dry air being fatal to them.
They can, ON the other hand, exist SUBJ
merged In water for several months.
They live chiefly in the superficial mold
less than foot below the surface, but
In long continued dry weather and In
very cold seasons they may burrow to a
depth of eight feet. The burrows are
lined by thin layer Of earth, voided
by the worms, and end in small cham
bers in which they can turn round.
The burrows are formed partly by
pushing away the earth, but chiefly by
the earth being swallowed. Large guam
ties Of earth are swallowed by the
worms for the sake Of the decomposing
vegetable matter contained in 1t, on
which they feed. The earth thus swal-
lowed is voided in spiral heaps, forming
the worm castings. In this case the
worm obtains food and at the same
time excavates its burrows.
In addition to the food thus obtained
half decayed leaves are dragged into the
burrows, mainly for food. but also to
plug the mouths of the burrows for the
sake Of protection. Worms are also fond
Of meat, especially fat. They will also
eat the dead. bodies Of their relatives.
They are nocturnal In habit, remaining,
as rule, in the burrows during the day
and coming out to feed at night.
The earthworm has no eyes, but is
affected by strong light If exposed to it
for some time. 1t has no sense OF hear
ing. but is sensitive to the vibrations Of
sound. The whole body is sensitive to
touch. There appears to be some sense
Of smell, but this is limited to certain
articles of food, which are discovered
by the worm when buried in earth, In
preference to other bodies not relished.
The worm appears to have some degree
of intelligence from the way in which
it draws the leaves into its burrows, al
ways judging which is the best end to
draw them in by. This is remarkable in
SO lowly organized an animal, being a
degree of intelligence not possessed by
many animals of more complex organi-
cation. For instance, the ant can often
be seen dragging objects along traversely
instead of taking them the easiest way.
As we have seen, vast quantities of
earth are continually being passed
through the bodies of worms and voided
on the surface as castings. When IL is
stated that the number of worms In an
acre of ordinary land suitable for them
to live In is SO, 900, we can imagine the
great effect which they must have on
the soil.
They are. in fact, continually plow-
ing the land. At one part Of the ali
mentary canal of the worm is gizzard.
or hard muscular organ. capable of
grinding food into fine particles. It is
this gizzard which is the main factor in
triturating the soil, and it is aided by
small stones swallowed with the earth,
which act as millstones.
In consequence Of the immense
amount of earth continually being
brought to the surface by worms it is
not difflcult to understand how objects,
such as stones. rocks, ETC., lying on the
surface will In course Of time become
gradually buried in the ground Owing
to the burial of stones and other objects
by the action of worms, ancient monu-
ments, portions Of Roman villas and
other objects of antiquity have been pre-
served. These have been gradually
buried by the worms and so preserved
from the destructive effect Of rain and
wind. Many Roman remains were stud
led by Darwin, and traces of the 40
ton of worms found, to which action
their preservation was mainly due. The
sinking Of the foundations of old build
ings is due to the action of worms, and
no building is safe from this unless the
foundations are laid lower than the
level at which the worms can work
namely. about eight feet below the sur
face.
Another useful effect produced by
worms is the preparation Of the soil for
the owth of seedlings. By their agency
the III is periodically sifted and expos
ed to the air. and In this way is able to
retain moisture and absorb soluble SUBJ
stances of use for the nutrition Of plants
knowledge.
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