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Darwin Correspondence Project

To Francis Darwin   22 [October 1881]1

66 Hills Road

Saturday 22d

My dear Frank

If you did not dislike the job, I think it wd. be a very good thing for you to review Wiesner. But you wd. have to read his book very carefully & consult his greater work on Heliotropism, which I think we have.2 I have now read 34 of his book. It is a great comfort that he has repeated almost all our experiments & finds our statements correct, but it is almost laughable how different an interpretation he puts on every single case. Without intending it he is unfair in some cases, by ignoring many experiments & selecting only certain ones from which to deduce his results. This is conspicuously the case with respect to the sensitiveness of the tip to contact, which he says he has repeated 100 times & always with our result.3 But his explanation seems to me ludicrous, & this is due to his ignoring all my many trials with gum water & with bits of card on opposite sides. You will be enabled well to discuss diaheliotropism; his explanation of which, as far as I can understand it, seems to me ludicrous.4

His book seems to me really a model of the spirit in which everyone ought to write controversially.—

I give up the ghost about cutting off tips of radicles; but it is a wonderful fact that slight relaxation of power of growth shd entirely check geotropism. If you can see young & vigorously growing fir-trees—measure whether upper lateral horizontally growing shoots are ever as long as the leader.— I will explain why this is important.5

I shall be able to point out various points in which I differ from him; but you will of course have to judge for yourself entirely so as to write conscientiously, if you agree to review the book.—

Yours affec | C. Darwin

I wonder whether he had previously come to the conclusion that pressure & extension plays so important a part in apparently simple heliotropic curvatures, or whether he was led to this conclusion by our book.6

I forgot to thank about Pinguicola— experiment quite failed7


The month and year are established by the address. The Darwins stayed with their son Horace and his wife, Ida Darwin, in Cambridge from 20 to 27 October 1881 (CD’s ‘Journal’ (Appendix II)).
See letter from Francis Darwin, [21 October 1881] and n. 3. Francis was thinking of reviewing Wiesner 1881. The other work by Julius Wiesner was ‘Die heliotropischen Erscheinungen im Pflanzenreiche’ (Heliotropic phenomena in the plant world; Wiesner 1878–80). CD had read an abstract of the work in 1878 and later cited it in Movement in plants, p. 12 (see Correspondence vol. 26, letter to Francis Darwin, 17 July [1878]).
See Wiesner 1881, p. 141.
See Wiesner 1881, pp. 107–29; Wiesner concluded that the phenomenon was a combination of negative geotropism (movement in opposition to gravity) and apheliotropism (movement away from light).
CD’s notes on the effects of removing the leader or lateral shoots or both in the Caucasian fir (Picea nordmanniana, a synonym of Abies nordmanniana subsp. nordmanniana) and silver fir (Abies pectinata, a synonym of A. alba), dated between 14 July 1879 and 26 January 1880, are in DAR 209: 6.
See Movement in plants, pp. 489–91.
Francis had sent a specimen of an unnamed species of Pinguicula (see letter from Francis Darwin, [21 October 1881] and n. 5); no experimental notes around this time on Pinguicula have been identified.


Movement in plants: The power of movement in plants. By Charles Darwin. Assisted by Francis Darwin. London: John Murray. 1880.

Wiesner, Julius. 1878–80. Die heliotropischen Erscheinungen im Pflanzenreiche. [Read 4 July 1878 and 18 March 1880.] Denkschriften der kaiserlichen Akademie der Wissenschaften, mathematisch-naturwissenschaftliche Classe 39 (1879) pt. 1: 143–209; 42 (1880) pt. 1: 1–92.

Wiesner, Julius. 1881. Das Bewegungsvermögen der Pflanzen. Eine kritische Studie über das gleichnamige Werk von Charles Darwin nebst neuen Untersuchungen. Vienna: Alfred Hölder.


Thinks FD should review Julius von Wiesner’s book [Das Bewegungsvermögen der Pflanzen (1881)]. CD comforted that Wiesner’s experiments support their findings but finds it laughable how differently he has interpreted them.

Letter details

Letter no.
Charles Robert Darwin
Francis Darwin
Sent from
Source of text
DAR 211: 87
Physical description
ALS 4pp

Please cite as

Darwin Correspondence Project, “Letter no. 13422,” accessed on 21 April 2024,