The Formation of Vegetable Mould Through the Action of Worms: With Observations on Their HabitsDarwin, Charles
Science
The Formation of Vegetable Mould Through the Action of Worms: With Observations on Their Habits
Darwin, Charles
Earthworms; Humification; Soils
At Stonehenge, some of the outer Druidical stones are now prostrate,
having fallen at a remote but unknown period; and these have become
buried to a moderate depth in the ground. They are surrounded by sloping
borders of turf, on which recent castings were seen. Close to one of
these fallen stones, which was 17 ft long, 6 ft. broad, and 28½ inches
thick, a hole was dug; and here the vegetable mould was at least 9½
inches in thickness. At this depth a flint was found, and a little
higher up on one side of the hole a fragment of glass. The base of the
stone lay about 9½ inches beneath the level of the surrounding ground,
and its upper surface 19 inches above the ground.
A hole was also dug close to a second huge stone, which in falling had
broken into two pieces; and this must have happened long ago, judging
from the weathered aspect of the fractured ends. The base was buried to
a depth of 10 inches, as was ascertained by driving an iron skewer
horizontally into the ground beneath it. The vegetable mould forming the
turf-covered sloping border round the stone, on which many castings had
recently been ejected, was 10 inches in thickness; and most of this mould
must have been brought up by worms from beneath its base. At a distance
of 8 yards from the stone, the mould was only 5½ inches in thickness
(with a piece of tobacco pipe at a depth of 4 inches), and this rested on
broken flint and chalk which could not have easily yielded to the
pressure or weight of the stone.
A straight rod was fixed horizontally (by the aid of a spirit-level)
across a third fallen stone, which was 7 feet 9 inches long; and the
contour of the projecting parts and of the adjoining ground, which was
not quite level, was thus ascertained, as shown in the accompanying
diagram (Fig. 7) on a scale of ½ inch to a foot. The turf-covered border
sloped up to the stone on one side to a height of 4 inches, and on the
opposite side to only 2½ inches above the general level. A hole was dug
on the eastern side, and the base of the stone was here found to lie at a
depth of 4 inches beneath the general level of the ground, and of 8
inches beneath the top of the sloping turf-covered border.
* * * * *
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Elsewhere in the archive
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account