SEARCH
0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Prev | Current Page 168 | Next

Darwin, Charles, 1809-1882

"The formation of vegetable mould through the action of worms, with observations on their habits"


Turning now to the points which more immediately concern us. Worm-
castings were observed on the floors of several of the rooms, in
one of which the tesselation was unusually perfect. The tesserae
here consisted of little cubes of hard sandstone of about 1 inch,
several of which were loose or projected slightly above the general
level. One or occasionally two open worm-burrows were found
beneath all the loose tesserae. Worms have also penetrated the old
walls of these ruins. A wall, which had just been exposed to view
during the excavations then in progress, was examined; it was built
of large flints, and was 18 inches in thickness. It appeared
sound, but when the soil was removed from beneath, the mortar in
the lower part was found to be so much decayed that the flints fell
apart from their own weight. Here, in the middle of the wall, at a
depth of 29 inches beneath the old floor and of 49.5 inches beneath
the surface of the field, a living worm was found, and the mortar
was penetrated by several burrows.
A second wall was exposed to view for the first time, and an open
burrow was seen on its broken summit. By separating the flints
this burrow was traced far down in the interior of the wall; but as
some of the flints cohered firmly, the whole mass was disturbed in
pulling down the wall, and the burrow could not be traced to the
bottom.


Pages:
156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180