CHAP. VI. AIDED BY WORMS. 265 



me after heavy rain, in many places on land 

 of all kinds. 



On the flowing of wet castings, and tlie 

 rolling of dry disintegrated castings down 

 inclined surfaces. When castings are ejected 

 on an inclined surface during or shortly 

 before heavy rain, they cannot fail to flow a 

 little down the slope. Thus, on some steep 

 slopes in Knole Park, which were covered 

 with coarse grass and had apparently existed 

 in this state from time immemorial, I found 

 (Oct. 22, 1872) after several wet days that 

 almost all the many castings were con- 

 siderably elongated in the line of the slope ; 

 and that they now consisted of smooth, only 

 slightly conical masses. Whenever the 

 mouths of the burrows could be found from 

 which the earth had been ejected, there was 

 more earth below than above them. After 

 some heavy storms of rain (Jan. 25, 1872) 

 two rather steeply inclined fields near Down, 

 which had formerly been ploughed and were 

 now rather sparsely clothed with poor grass, 

 were visited, and many castings extended 

 down the slopes for a length of 5 inches, 

 which was twice or thrice the usual diameter 



