Vermont phÅ“nix. [volume] (Brattleboro, Vt.) 1834-1955, 1882-01-13
The Influence Of Earth.WOrms on
the Soil.

The London Saturday Review has the fol-
lowing summary Of some of the remarkable
statements made by Mr.. Darwin in his new
volume on worms:
From careful measurements Of the weight
of earth elected from a single burrow and
from number of burrows within a given
space, he has come to results which striking
ly show the important part played by these
seemingly insignificant agents in the econo-
my of nature. In field near Nice the cast
ings within one square foot of surface were
found to weigh twelve ounces year, equiva-
lent to 14.5S tons per acre. Upon n chalk
down in Kent So 81 lbs. were accumulated
in the square yard, equal to 1912 tons per
acre. Near Leith Hill, Surrey, the yield was
calculated at 1866 tons annually on one piece
of land and 1911 tons on another. If uniform
ly spread out over the surface, the castings
elected would amount, Mr.. Darwin estimates
from q number of instances, to a thickness
of about one and a half inches in ten years
The number of worms to be met with in an
acre of garden land has been estimated by
Hensen at 90, 7G7; but, taking half this
amount as the yield of average land, it may
be inferred that each worm elects some TWEEN
ty ounces n year in about the same number
of castings. Considering that many bur
row extends to three, four, or even five feet
in depth, il is easy to conceive the amount of
change perpetually going on in the amount
of subsoil, fresh and virgin mould being
brought up by these untiring miners to re-
new and fertilize the upper earth. At the
same time they carry on the process of bury
ing objects resting on the surface-stones,
bricks and other debris sinking to all appear
ance with the lapse of time the fact being
that the worm casts are heaped up alongside
and over them till they become entirely hid
den from view.
Instances are given of great stones, the ap-
parent sinking of which has been measured.
One which had lain in grass field for thirty
five years has been buried to the extent Of
one and one-half inches below the original
surface another larger stone about two inch
es, the mould rising to several inches higher
against the sides of the stone from the fact of
the worms working under it having to eject
their castings clear Of the under surface, and
thus piling them to a height above the aver
age level. A sloping field near Mr. Darwins
house had been SO thickly covered with hints
great and small as to be called the stony
field As his sons ran down the field the
stones cattered together. In thirty years
they had been so thoroughly buried that
horse could gallop from one end of the field
to another and not strike with his shoes a
single stone. A tagged path was similarly
CONtIbu up III hDOuL INC same space OF Time.
A layer of coal ashes strewn upon the surface
was found in a distinctly marked line, within
eighteen years, seven inches under the soil
In New Zealand there was found, from three
to six inches underground a layer of rude
weapons and implements, flakes and chips of
basalt, dropped by the aborigines upon the
surface. Farmers are wont to speak of lime,
cinders, and heavy stones working them
selves downward : and Mr.. Darwin throws
out hint for surveyors as to the possibility
of their bench stones set in the ground to
mark the levels being turned by the under
mining of worms into false standards.
Still more curious are the results indicated
by remains of ancient buildings. The floors
and walls of Roman villas at Abinger, Ched-
worth, Silchester, and Bradng, penetrated
and buried by worm casts, form an excellent
index to the rate of accumulation. Pave
ments have been lowered by the gradual
withdrawal of the underlying soil. At Sill
chester the centre tesserp are found five and
three-quarters inches below the line where
those at the sides of the apartments Join the
wall, being thereby kept from subsiding.
The ponderous trilithons of Stonehenge have
undergone for ages the process of slow inter-
ment by the accumulation of mould around
them, at the same time that they are in dan
ger of lettering and falling from being under
mined by these tiny assailants. On the other
hand, we are often indebted to them for the
preservation of coins, weapons and orna-
ments of metal and stone and relics of all
kinds. Arch@ologists are reminded by Mr.. |
Darwin of what they owe to the despised
earth-worm. The agriculturist, the lover of
the picturesque, the economical philosopher,
the practical statesman, may join in grateful
of services which have so
largely helped to clothe the earth with rich
ness and beauty. All lovers of nature we
llay add. will unite in thanking Mr.. Darwin
for the new and interesting light he has
thrown upon subject so long overlooked, |
yet so full of interest and instruction, as the |
structure and the labors of the earth-worm." |