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Show 104 II.A.BITS OF WORMS. CIIAP. II. another place at no great distance tho castings were white ; and why the. worms should have burrowed into the chalk 1n some places and not in others, I am unable to conjecture. Two O'reat piles of leaves had been left to decay in° my grounds, and months after their removal, the bare surface, several yards in dian1eter, 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 tho number of spores of various shapes and sizes which it contained was astonishingly great; and these crushed in the gizzards of worms rna y larO'e]y aid in supporting them. When- a . ever castings are thrown up 1n 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, CrrAr. II. EARTII SWALLOWED AS FOOD. 105 and every morning many fresh castings wore seen; but not a single Jeafwas drawn into these burrows. Thee 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. On what could those worms have subsisted during this whole time, if not on matter contained in the black earth? On the other hand, whenever a large number of leaves arc drawn into the burrows, the worms seem to subsist chiefly on them, for few earth-castings are then ejected on the surface. This difference in the behaviour of worms at different times, perhaps explains a statement by Claparede, namely, that triturated leaves and earth are always found in di tinct parts of their intestines. Worms sometimes abound in places where they can rarely or never obtain dead or living leaves; for instance, beneath the pavement in well-swept courtyards, into which leaves are only occasionally blown. My son Horace examined a house, one corner of which had subsided; and he found here in the cellar, which was extremely damp, many small worm-castings thrown up between the |