104 HABITS OF WORMS. Chap. U. 



another place at no great distance the 

 castings were white ; and why the worms 

 should have burrowed into the chalk in some 

 places and not in others, I am unable to 

 conjecture. 



Two great piles of leaves had been left to 

 decay in my grounds, and months after their 

 removal, the bare surface, several yards in 

 diameter, was so thickly covered during 

 several months with castings that they formed 

 an almost continuous layer; and the large 

 number of worms which lived here must have 

 subsisted during these months on nutritious 

 matter contained in the black earth. 



The lowest layer from another pile of de- 

 cayed leaves mixed with some earth was ex- 

 amined under a high power, and the number 

 of spores of various shapes and sizes which 

 it contained was astonishingly great; and 

 these crushed in the gizzards of worms may 

 largely aid in supporting them. When- 

 ever castings are thrown up in the greatest 

 number, few or no leaves are drawn into the 

 burrows ; for instance the turf along a hedge- 

 row, about 200 yards in length, was daily 

 observed in the autumn during several weeks, 



