From:
Joseph Henry Gilbert
To:
Charles Robert Darwin
Date:
9 Jan 1882
Source of text:
DAR 165: 45
Summary:
Thanks CD for Earthworms.
Discusses the problem of accounting for difference between nitrogen in permanent grassland and ordinary arable soil. Finds castings of earthworms rich in nitrogen. Asks CD if his observations enable him to explain the source. If from below top-soil, it would be a considerable manuring.
Contributor:
Darwin Correspondence Project
