THE 



FORMATION OF VEGETABLE MOULD, 



THROUGH THE ACTION OP WORMS, WITH 

 OBSERVATIONS ON THEIR HABITS. 



INTRODUCTION. 



The sbare 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 com- 

 posed is one of its chief characteristic features ; 

 and this may be well observed in any gravelly 

 country, where a recently-ploughed field 



