Page:The Formation of Vegetable Mould through the Action of Worms (1881).djvu/11

Rh weight of earth ejected from a burrow, and from all the burrows within a given space—The thickness of the layer of mould which the castings on a given space would form within a given time if uniformly spread out—The slow rate at which mould can increase to a great thickness—Conclusion

CHAPTER IV.

THE PART WHICH WORMS HAVE PLAYED IN THE BURIAL OF ANCIENT BUILDINGS.

CHAPTER V.

THE ACTION OF WORMS IN THE DENUDATION OF THE LAND.

Evidence of the amount of denudation which the land has undergone—Subaerial denudation—The deposition of dust—Vegetable mould, its dark colour and