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Darwin Correspondence Project

To Grant Allen   [before 21 February 1879]1

Down Beckenham Kent

Dear Sir

I have read the whole of your Book with great interest.2 It contains very many views new to me & highly ingenious, & some new facts. I read it, however, to avoid fatigue in an uncritical spirit: Nevertheless shades of doubt crossed my mind often. You impress me with having so ardent a love of truth, that I believe you will prefer hearing a few unfavourable remarks rather than more praise.—

(p. 73 Sprengel & not Lubbock ought to be referred to about the mark “saft-maal” to guide insects. During many a year I could not believe in their meaning, until I found that their development was correlated with that of the nectary. see p 373 Cross-Fertilisation of Plants.)3

(Wiesner of Vienna has shown that Chlorophyll in young & tender parts is injured by an excess of light. & he believes that the red scales &c at end of shoots &c serve to protect the parts from those rays which are the most injurious.)4

p. 39 | Before you have another edition, pray consult good authorities, about 2 individuals of Cryptogamic Plants not intercrossing: I believe that you will find this dreadfully erroneous. In Fucus sexes often distinct. With Ferns. why should not male & female elements have been enclosed in same receptacle, except to allow of occasional crossing? & hybrid Forms have occasionally appeared.— Think again on the conjugation of distinct Algæ— conjugation being the precursor of sexual generation.— Pray read my discussion on the origin of sexes in last chapter of Cross Fertilisation.)5

p. 131 (I am now going to make a criticism beyond my tether; but I cannot believe in your theory of the origin of pleasure & pain; & I must think that these sensations have been specially acquired as a guide to each creature. Why shd the stimulation from Sugar give much pleasure to the gustatory nerves, & touching during the act of eating, not give pleasure to the delicate tactile nerves of the tongue & lips? If it had been highly advantageous to an animal that its lips shd be occasionally rubbed gently, then, I believe, the tactile nerves could have acquired pleasure in the act,— as in another part of the body, which need not be specified.6

(I am glad that you defend sexual selection: I have no fear about its ultimate fate, though now at a discount.— Wallace’s explanation of, for instance, the display of a Peacock seems to me mere empty words— For many years I have quite doubted his scientific judgment, though admiring greatly his ingenuity & originality.—)7

(Dr Hochberg (under the name of Dr Berg) lately sent me a pamphlet in German which I have only skimmed, but which seemed to me clever: he maintains, (somewhat like you about colour with ⁠⟨⁠birds and⁠⟩⁠ Butterflies) that the origin of sexual music is the ⁠⟨⁠3 or 4 words excised⁠⟩⁠ He also speculates on sense of ⁠⟨⁠3 or 4 words excised⁠⟩⁠ our progenitors having been fruit-⁠⟨⁠3 or 4 words excised⁠⟩⁠ ⁠⟨⁠se⁠⟩⁠cond note (asking me to get his paper translated ⁠⟨⁠3 or 4 words excised⁠⟩⁠ not do) he says he now finds that you have published similar views on colour.—)8

(I may mention that some years ⁠⟨⁠ag⁠⟩⁠o Fritz Müller expressed opinion in letter that the sight of beautiful flowers had influenced the sexual selection of Butterflies.— Before that I had speculated whether the sombre aspect of nature in Galapagos (under Equator) & in Patagonia had not destroyed taste for beautiful colours in the Birds of these Districts. I believe that I inserted a sentence to this effect; but I remember being frightened at such bold speculations, & perhaps struck out the passage.— The contrast in the colour of the birds in Patagonia, & on the bright-green, flower-decked plains of La Plata is very striking.—)9

I fear that you will hardly be able to decipher this letter (my Amanuensis is away)10 & perhaps not think it worth deciphering:—

I hope that you received my note acknowledging safe receipt of your Book.—11


The date is established by the relationship between this letter and the letter from Grant Allen, 21 February [1879].
Allen had asked his publisher to send CD a copy of The colour-sense: its origin and development: an essay in comparative psychology (G. Allen 1879a); see letter from Grant Allen, 12 February 1879. CD’s annotated copy of G. Allen 1879a is in the Darwin Library–CUL (see Marginalia, pp. 14–15).
In Sprengel 1793, p. 38, Christian Konrad Sprengel had observed that a spot of a different colour from the rest of the petal of a flower acted as a guide leading insects to the nectar within; he referred to this guide as Saftmaal (nectar mark; German). Allen credited John Lubbock with the idea in G. Allen 1879a, p. 73. In Cross and self fertilisation, p. 373, CD gives a case where these marks have been developed in correlation with the nectary.
Julius Wiesner had written ‘Die natürliche Einrichtungen zum Schutze des Chlorophylls der lebenden Pflanze’ (Natural contrivances for the protection of chlorophyll in living plants; Wiesner 1876); see pp. 41–2.
Allen had stated that cryptogamic reproduction was ‘essentially hermaphrodite or non-sexual in its character’ and cited CD’s Cross and self fertilisation on the advantages of cross-fertilisation (G. Allen 1879a, p. 39). For CD’s discussion of the genesis of the sexes and the many structures that allow the occasional cross in hermaphrodite plants, see Cross and self fertilisation, pp. 461–3. Fucus is a genus of brown algae; it is no longer classified as a plant but is in the kingdom Chromista (for its nineteenth-century classification, see Thuret 1854–5). The existence of hybrid ferns was debated at this time; see, for example, Proceedings of the Royal Horticultural Society 5 (1865): 167–8. Conjugation: the union or fusion of two (apparently) similar cells for reproduction, occurring in certain plants and animals of lowly organisation (OED).
For Allen’s theory of the origin of pleasure with reference to sugar, see G. Allen 1879a, pp. 109–10.
Allen defended CD’s theory of sexual selection against Alfred Russel Wallace’s objections in G. Allen 1879a, pp. 155–94. Wallace had argued that the tail and elaborate display of the peacock could be explained by the vigour and vitality of the male bird; see Wallace 1877 and Correspondence vol. 25, letter to A. R. Wallace, 31 August 1877.
The pamphlet that Karl Höchberg sent CD was probably ‘Die Lust an der Musik’ (The desire for music; Berg 1879); see letter to Karl Höchberg, 13 January 1879. In Höchberg’s reply to CD of 17 January 1879, he referred to Allen’s new book on colour sense (G. Allen 1879a) and asked whether his pamphlet was of sufficient merit to be translated into English.
For Fritz Müller’s observation that some species of butterflies preferred certain colours and the implications of this for the sexual selection of protective imitation, see Correspondence vol. 19, letter from Fritz Müller, 14 June 1871. For the passage in response to Müller’s letter that CD did not add to Descent 2d ed., see ibid., letter to Fritz Müller, 2 August [1871]. In Descent 2d ed., p. 422 n. 34, CD maintained that it was difficult to account for the dull colours of birds in the Galápagos Islands and Patagonia and noted that he had speculated on whether the prevailing dull tints of the scenery in these countries had affected the appreciation of bright colours by the birds inhabiting them.
Francis Darwin was CD’s secretary and assistant but he was in Algiers; see letter from Francis Darwin, [c. 25 February 1879].
The note from CD has not been found. CD’s signature has been excised, causing damage to other parts of the letter.


Allen, Grant. 1879a. The colour-sense: its origin and development. An essay in comparative psychology. London: Trübner & Co.

Berg, H. 1879. Die Lust an der Musik: nebst einem Anhang, Die Lust an den Farben, den Formen und der körperlichen Schönheit. Berlin: B. Behr’s Buchhandlung (E. Bock).

Sprengel, Christian Konrad. 1793. Das entdeckte Geheimniss der Natur im Bau und in der Befruchtung der Blumen. Berlin: Friedrich Vieweg.

Thuret, Gustave Adolphe. 1854–5. Recherches sur la fecondation des Fucacées, suivies d’observations sur les anthéridies des Algues. Annales des sciences naturelles (botanique) 4th ser. 2: 197–214; 3: 5–28.

Wiesner, Julius. 1876. Die natürliche Einrichtungen zum Schutze des Chlorophylls der lebenden Pflanze. In Festshrift zur Feier des funfundzwanzigjährigen Bestehens der k. k. zoologisch-botanischen Gesellschaft in Wien. Vienna: W. Braumüller. Leipzig: F. A. Brockhaus.


Read GA’s book [The colour-sense] with "great interest". Makes criticisms and suggestions.

Cannot believe in GA’s theory of the origin of pleasure and pain.

Is glad he defends sexual selection;

CD finds A. R. Wallace’s explanations "mere empty words" and for many years he has "quite doubted [ARW’s] scientific judgment".

Considers the possible effect of environmental colour on the colour tastes of animals.

Letter details

Letter no.
Charles Robert Darwin
Charles Grant Blairfindie (Grant) Allen
Sent from
Source of text
Cleveland Health Sciences Library (Robert M. Stecher collection)
Physical description
AL inc

Please cite as

Darwin Correspondence Project, “Letter no. 11891,” accessed on 16 August 2022,