Chap. III. ANNUALLY ACCUMULATED. 175 



mingle the whole with vegetable de'bris, and 

 to saturate it with their intestinal secretions. 



Finally, no one who considers the facts 

 given in this chapter on the burying of 

 small objects and on the sinking of great 

 stones left on the surface on the vast 

 number of worms which live within a 

 moderate extent of ground on the weight of 

 the castings ejected from the mouth of the 

 same burrow on the weight of all the cast- 

 ings ejected within a known time on a measured 

 space will hereafter, as I believe, doubt that 

 worms play an important part in nature. 



