CHAP. VI. AIDED BY WORMS. 279 



these castings are extremely liable to crumble 

 during dry weather into small fragments, 

 which are soon acted on by rain, and then 

 sink down so as to be no longer distinguish- 

 able from the surrounding soil. He sent me 

 a mass of such disintegrated castings, collected 

 on the top of a bank, where none could have 

 rolled down from above. They must have 

 been ejected within the previous five or six 

 months, but they now consisted of more or less 

 rounded fragments of all sizes, from f of an 

 inch in diameter to minute grains and mere 

 dust. Dr. King witnessed the crumbling 

 process whilst drying some perfect castings, 

 which he afterwards sent me. Mr. Scott also 

 remarks on the crumbling of the castings 

 near Calcutta and on the mountains of 

 Sikkim during the hot and dry season. 



When the castings near Nice had been 

 ejected on an inclined surface, the disinte- 

 grated fragments rolled downwards, without 

 losing their distinctive shape ; and in some 

 places could " be collected in basketfuls." Dr. 

 King observed a striking instance of this fact 

 on the Corniche road, where a drain, about 

 2^ feet wide and 9 inches deep, had been made 



