ABSTRACT

EXPERIMENT N O . I. (Vegetable Mould). Darwin's1 attention became drawn to two facts: cinders, stones,

and the like, which had been thickly strewn over several meadows were found after some years some centimetres below the surface but still in a layer; and undisturbed fields are found to be covered with what is known as vegetable mould, which is blackish and is composed of particles of uniform fineness. Such facts would be contrary to one's expectations. It seemed to him that the two facts were connected: he entertained the hypothesis that the stones were covered by the mould which was brought to the surface by earthworms in the form of castings. Accordingly he set out to answer the question whether this was so.