Buchanan County bulletin. [volume] (Independence, Iowa) 1869-1891, 1877-11-09
The Agricultural Value OF Worms.
Scientific American.

Scientific American.
In 1887 Mr. Darwin, in a paper read
before the British Geological Society,
explained how the formation Of vegeta-
BILE mold which covers several inches in
depth on the surface of productive land,
was directly due to the common earth
worm. The soil, he stated, was simply
the non-nutritious matter contained in
the earth originally eaten by the worm
and rejected by it, and the accumulated
deposits of large numbers Of worms pro-
duced the extensive layers commonly
found, Quite recently Herr Won Han
sen has investigated further into this
subject and has confirmed Darwin's con-
illusions while supplementing many of
his own. An abstract Of his investiga-
lions appears in the XIXth Century.
He states that the adult worms come
to surface at night, and, with their tails
in their burrows, collect the twigs,
leaves, ETC., which serve as their food.
This material is heaped around the ORR
flee of the burrow, and is drawn in piece
by piece, the leaves in time becoming
macerated and decomposed, and thus
rendered suitable for the worms eating.
The investigations were conducted in a
garden having layer Of mold 8 inches
deep and a subsoil of yellow diluvial
sand. The worm tubes were not easily
traced in the mold, but were perfectly
clear in the sand, running vertically
downwards to depth of from three to
five feet On the walls Of these bur
rows the black masses of eXcrement OF
the worms were plainly visible. Some
of the tubes were entirely filled with
this substance, the black color of which
was diffused into the adjacent soil. In
about half the inhabited tubes, plant
roots had entered, following their course
By extended observations the author
states that the roots of ANNALS can on
ly penetrate into the subsoil through
channels opened out to them by earth
worms, and he observes that this penetra-
ton must be Of service to the plant, as
the subsoil retains moisture longer than
the surface layer of the mold.
In order to ascertain the precise part
taken by the worm in making this vege-
table mold, two worms were placed in a
glass vessel filled with sand on the sur
face of which was spread layer Of fall
en- leaves. The worms set to work at
once, and after about six weeks the sur
face Of the sand was found to be cover
ed with layer of mold nearly half an
inch deep, while many leaves had been
carried to a depth of three inches
Worm tubes ran in all directions through
the sand; some were quite fresh, others
had a wall of mold an eighth of an inch
thick, others, again, were completely
filed with mold. In short, the soil OF
the vessel was already perfectly well
prepared for the growth of plants.
Herr Won Hensen finds that, although
the earth worm weighs only about 46
grains, it produces in four hours nearly
grains Of excremcntitious matter. On
an average he finds about 1900 worms
to an acre of ground. Their combined
weight is therefore over 220 pounds and
they produce about 81 pounds OF mold
in twenty-four hours. Besides this,
they produce uniform distribution OF
the mold, open up passages in the sub
soil for roots, and render the subsoil fer
tile.