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Darwin Correspondence Project

To F. T. Köppen   28 April [1871]1

Down. | Beckenham | Kent. S.E.

April 28th

Dear Sir

I am greatly indebted to you for your valuable present of your Heuschrecken in Südrussland & for your interesting letter.2 I have no doubt I shall find much matter of value to me in your volume; but unfortunately I am a poor German scholar & read the language with much difficulty, which has been an irreparable loss to me.— The facts which you mention in your letter in relation to the increase of mice &c from the invasion of the grasshoppers are very curious; & it is a subject which always possesses a special interest for me.3

With much respect & my best thanks, I remain | Dear Sir | Yours faithfully | Ch. Darwin


The year is established by the relationship between this letter and the letter from F. T. Köppen, 25 April 1871.
CD refers to Köppen 1865 (On locusts in south Russia) and to the letter from F. T. Köppen, 25 April 1871.
CD touched on a similar relationship between mammal, insect, and plant in Origin, pp. 73–4, where he discussed the interactions of bees, cats, and mice in clover fields.


Thanks for FTK’s locust paper ["Die geographische Verbreitung der Wanderheuschrecke", Petermann’s Geogr. Mittheil. (1871)].

Letter details

Letter no.
Charles Robert Darwin
Friedrich Theodor Köppen (Keppen, Fedor Petrovich)
Sent from
Source of text
Russian Academy of Sciences, Moscow
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 7723,” accessed on 19 April 2018,

Also published in The Correspondence of Charles Darwin, vol. 19