OCR Text |
Show THE FORMATION OF VEGETABLE MOULD, THROUGH TilE ACTION OF WORMS, WITH OBSERVATIONS ON THEIR HABITS. INTRODUCTION. TrrE share which worms have taken in the formation of the layer of vegetable mould, which covers the whole surface of the land in every moderately humid · country, is the subject of the present volume. This mould is generally of a blackish colour and a few inches in thickness. In different districts it differs but little in appearance, although it may rest on various subsoils. The uniform fineness of the particles of which it is composed is one of its chief characteristic features ; and this may be well observed in any gravelly country, where a recently-ploughed field B |