From F. T. Köppen 25 April 1871
Summary
Sends his paper on locusts ["Die geographische Verbreitung der Wanderheuschrecke", Petermann’s Geogr. Mittheil. (1871)]. The effect of the growth of forest land on their increase; meteorological and climatic effects.
Also observations made on increase in mice as a result of increase of locusts, on whose eggs they fed, and of increase of weasels that fed on mice.
Author: | Friedrich Theodor Köppen (Fedor Petrovich Keppen) |
Addressee: | Charles Robert Darwin |
Date: | 25 Apr 1871 |
Classmark: | DAR 46.1: 102 |
Letter no: | DCP-LETT-7716 |
From F. T. Köppen 13 November 1874
Summary
Calls CD’s attention to a book that deals with subjects related to both Descent and Expression: Ferdinand Jahn, Die abnormen Zustände des menschlichen Lebens als Nachbildungen und Wiederholungen normaler Zustände des Thierlebens [1842].
Author: | Friedrich Theodor Köppen (Fedor Petrovich Keppen) |
Addressee: | Charles Robert Darwin |
Date: | 13 Nov 1874 |
Classmark: | DAR 91: 84 |
Letter no: | DCP-LETT-9719 |
Darwin, C. R. | (2) |
Darwin, C. R. | |
Köppen, F. T. | (2) |