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 174 | Next

Darwin, Charles, 1809-1882

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

In most places it is only about 9 inches in thickness,
but in some places 12 or even more inches. In Fig. 11, it is given
as 20 inches, but this section was drawn by Mr. Joyce before his
attention was particularly called to this subject. The land
enclosed within the old walls is described as sloping slightly to
the south; but there are parts which, according to Mr. Joyce, are
nearly level, and it appears that the mould is here generally
thicker than elsewhere. The surface slopes in other parts from
west to east, and Mr. Joyce describes one floor as covered at the
western end by rubbish and mould to a thickness of 28.5 inches, and
at the eastern end by a thickness of only 11.5 inches. A very
slight slope suffices to cause recent castings to flow downwards
during heavy rain, and thus much earth will ultimately reach the
neighbouring rills and streams and be carried away. By this means,
the absence of very thick beds of mould over these ancient ruins
may, as I believe, be explained. Moreover most of the land here
has long been ploughed, and this would greatly aid the washing away
of the finer earth during rainy weather.
The nature of the beds immediately beneath the vegetable mould in
some of the sections is rather perplexing. We see, for instance,
in the section of an excavation in a grass meadow (Fig.


Pages:
162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186