[54]

(54

[in another hand:] c. 1880

Ch IV 5

Charles Darwin

period as 2000 years a great amount of earth will have been brought to the surface or any most old embankments or & tumuli, especially on the Talus round their bases, & much of this earth will have been washed away. We may, therefore, conclude that all such old ancient works, when not formed of unfavourable materials, will have been somewhat lowered in the course of centuries, although their inclination may not have been greatly lessened. chang modified.)

Fields formerly ploughed. ─ From a very remote period & in many countries land has often been ploughed, so that convex beds, called crowns or ridges, usually usually 8 ft across across, & separated by furrows, have been thrown up. The furrows are [illeg] diverted so as to carry off the surface water. In my attempts to ascertain how long the crowns and furrows last, after ploughed land has been converted in pasture Paf obstacles of many kinds were encountered. It is rarely known when a field was last ploughed; & some fields which were thought to have been in pasture from time immemorial were afterwards found to have been ploughed only 50 or 60 years before. During the early part

[Earthworms, pp. 292-3: "Therefore in so long a period as 2000 years, a large amount of earth will have been repeatedly brought to the surface on most old embankments and tumuli, especially on the talus round their bases, and much of this earth will have been washed completely away. We may therefore conclude that all ancient mounds, when not formed of materials unfavourable to worms, will have been somewhat lowered in the course of centuries, although their inclinations may not have been greatly changed.
Fields formerly ploughed.—From a very remote period and in many countries, land has been ploughed, so that convex beds, called crowns or ridges, usually about 8 feet across and separated by furrows, have been thrown up. The furrows are directed so as to carry off the surface water. In my attempts to ascertain how long a time these crowns and furrows last, when ploughed land has been converted into pasture, obstacles of many kinds were encountered. It is rarely known when a field was last ploughed; and some fields which were thought to have been in pasture from time immemorial were afterwards discovered to have been ploughed only 50 or 60 years before. During the early part of the present century, when the price of corn was very high, land of all kinds seems to have been ploughed in Britain."]

[54v]

[verso in the hand of Emma Darwin with corrections by Darwin]

54

Ch IV

embankment or tumulus 2000 years old would if none of it were not removed have passed would be brought to the sur about 200 times with the kind through the intestines of worms, & thus have been brought to the surface. As on each set of occasion the castings in their soft condition would be eminently liable to be washed to a lower level, & it is impossible to doubt that all ancient embankments and tumuli must in the course of centuries have been be somewhat lowered though their shapes slopes may not be greatly altered.

[Earthworms, p. 292: "Therefore in so long a period as 2000 years, a large amount of earth will have been repeatedly brought to the surface on most old embankments and tumuli, especially on the talus round their bases, and much of this earth will have been washed completely away. We may therefore conclude that all ancient mounds, when not formed of materials unfavourable to worms, will have been somewhat lowered in the course of centuries, although their inclinations may not have been greatly changed."]