Chap. VI. LEDGES ON HILL-SIDES. 281 



the inland side of Beachy Head, where the 

 surface sloped at about 25°, many short little 

 embankments like those just mentioned. 

 They extended horizontally and were from a 

 few inches to two or three feet in length. 

 They supported tufts of grass growing 

 vigorously. The average thickness of the 

 m.ould of which they were formed, taken 

 from nine measurements, was 4' 5 inches; 

 while that of the mould above and beneath 

 them was on an average only 3"2 inches, and 

 on each side, on the same level, 3"1 inches. 

 On the upper parts of the slope, these em- 

 bankments showed no signs of having been 

 trampled on by sheep, but in the lower parts 

 such signs were fairly plain. No long con- 

 tinuous ledges had here been formed. 



If the little embankments above the Cor- 

 niche road, which Dr. King saw in the act 

 of formation by the accumulation of dis- 

 integrated and rolled worm-castings, were to 

 become confluent along horizontal lines, ledges 

 would be formed. Each embankment would 

 tend to extend laterally by the lateral extension 

 of the arrested castings; and animals grazing on 

 a steep slope would almost certainly make use 



