Page:The Formation of Vegetable Mould through the Action of Worms (1881).djvu/299

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Chap. VI.
CASTINGS BLOWN TO LEEWARD.
285

above the mouths and on the windward side as 2¾ to 1; whereas we have seen that with several castings which had flowed down slopes having a mean inclination of 9° 26′, and with three castings where the inclination was above 12°, the proportional weight of the earth below to that above the burrows was as only 2 to 1. These several cases show how efficiently gales of wind accompanied by rain act in displacing recently-ejected castings. We may therefore conclude that even a moderately strong wind will produce some slight effect on them.

Dry and indurated castings, after their disintegration into small fragments or pellets, are sometimes, probably often, blown by a strong wind to leeward. This was observed on four occasions, but I did not sufficiently attend to this point. One old casting on a gently sloping bank was blown quite away by a strong south-west wind. Dr. King believes that the wind removes the greater part of the old crumbling castings near Nice. Several old castings on my lawn were marked with pins and protected from any disturbance. They were examined after an interval of 10