Page:The Formation of Vegetable Mould through the Action of Worms (1881).djvu/293

 on the Alps of Switzerland, and states that they ran at 3 or 4 ft. one above the other, and were about a foot in breadth. They had been deeply pitted by the feet of grazing cows. Similar ledges were observed by the same friend on our Chalk downs, and on an old talus of chalk-fragments (thrown out of a quarry) which had become clothed with turf.

My son Francis examined a Chalk escarpment near Lewes; and here on a part which was very steep, sloping at 40° with the horizon, about 30 flat ledges extended horizontally for more than 100 yards, at an average distance of about 20 inches, one beneath the other. They were from 9 to 10 inches in breadth. When viewed from a distance they presented a striking appearance, owing to their parallelism; but when examined closely, they were seen to be somewhat sinuous, and one often ran into another, giving the appearance of one ledge having forked into two. They are formed of light-coloured earth, which on the outside, where thickest, was in one case 9 inches, and in another case between 6 and 7 inches in thickness. Above the ledges, the thickness of the earth over the chalk was in