Chap. VI. AIDED BY WORMS. 275 



its castings, not in vermiform masses, but in 

 little pellets of varying sizes : these are very 

 numerous in some places, and Mr. Scott says 

 that they " are washed away by every 

 " shower." 



I was led to believe that a considerable 

 quantity of fine earth is washed quite away 

 from castings during rain, from the surfaces 

 of old ones being often studded with coarse 

 particles. Accordingly a little fine precipi- 

 tated chalk, moistened with saliva or gum- 

 water, so as to be slightly viscid and of the 

 same consistence as a fresh casting, was 

 placed on the summits of several castings and 

 gently mixed with them. These castings 

 were then watered through a very fine rose, 

 the drops from which were closer together 

 than those of rain, but not nearly so large as 

 those in a thunder-storm ; nor did they strike 

 the ground with nearly so much force as 

 drops during heavy rain. A casting thus 

 treated subsided with surprising slowness, 

 owing as I suppose to its viscidity. It did 

 not flow bodily down the grass-covered sur- 

 face of the lawn, which was here inclined at 

 an angle of 16° 20'; nevertheless many par- 



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