Page:The Formation of Vegetable Mould through the Action of Worms (1881).djvu/315

 would cease to be ejected or would become scanty.

The following cases show that a considerable quantity of fine earth is washed down. The thickness of the mould was measured at points 12 yards apart across a small valley in the Chalk near Winchester. The sides sloped gently at first; then became inclined at about 20°; then more gently to near the bottom, which transversely was almost level and about 50 yards across. In the bottom, the mean thickness of the mould from five measurements was 8.3 inches; whilst on the sides of the valley, where the inclination varied between 14° and 20°, its mean thickness was rather less than 3.5 inches. As the turf-covered bottom of the valley sloped at an angle of only between 2° and 3°, it is probable that most of the 8.3-inch layer of mould had been washed down from the flanks of the valley, and not from the upper part. But as a shepherd said that he had seen water flowing in this valley after the sudden thawing of snow, it is possible that some earth may have been brought down from the upper part; or, on the other hand, that some may have been