From:
Charles Robert Darwin
To:
Francis Darwin
Date:
17 July [1878]
Source of text:
DAR 211: 37
Summary:
Discusses sleep movements of Porlieria.
Has read an abstract of Julius Wiesner on heliotropism and geotropism ["Die heliotropischen Erscheinungen im Pflanzenreiche", Anz. Kais. Akad. Wiss. Wien 15 (1878): 137–40] which seems important but is puzzling.
Gives details of his observations on climbing plants with reference to comments by Julius Sachs.
Contributor:
Darwin Correspondence Project