In another
place at no great distance the castings were white; and why the
worms should have burrowed into the chalk in some places and not in
others, I am unable to conjecture.
Two great piles of leaves had been left to decay in my grounds, and
months after their removal, the bare surface, several yards in
diameter, was so thickly covered during several months with
castings that they formed an almost continuous layer; and the large
number of worms which lived here must have subsisted during these
months on nutritious matter contained in the black earth.
The lowest layer from another pile of decayed leaves mixed with
some earth was examined under a high power, and the number of
spores of various shapes and sizes which it contained was
astonishingly great; and these crushed in the gizzards of worms may
largely aid in supporting them. Whenever castings are thrown up in
the greatest number, few or no leaves are drawn into the burrows;
for instance the turf along a hedgerow, about 200 yards in length,
was daily observed in the autumn during several weeks, and every
morning many fresh castings were seen; but not a single leaf was
drawn into these burrows. These castings from their blackness and
from the nature of the subsoil could not have been brought up from
a greater depth than 6 or 8 inches.
Pages:
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102