From A. R. Wallace   23 July 1877

Rosehill, Dorking.

July 23rd. 1877

My dear Darwin

Many thanks for your admirable volume on “The Forms of Flowers."1 It would be impertinence of me to say anything in praise of it except that I have read the Chapters on “Illegitimate Offspring of Heterostyled Plants”—and on “Cleistogamic Flowers” with great interest.

I am almost afraid to tell you that in going over the subject of the “Colours of Animals &c. for a small volume of essays &c. I am preparing I have come to conclusions directly opposed to voluntary sexual selection, and believe that I can explain (in a general way) all the phenomena of sexual ornaments & colours by laws of development aided by simple “natural selection”.2

I hope you admire as I do Mr Belt’s remarkable series of papers in support of his terrific “oceanic glacier” river damming” hypothesis. In awful grandeur it beats everything “glacial” yet out, & it certainly explains a wonderful lot of hard facts. The last one, on the “Glacial Period in the Southern Hemisphere” in the Quarterly Journal of Science, is particularly fine, & I see he has just read a paper at the Geol. Soc. It seems to me supported by quite as much evidence as Ramsay’s “Lakes”—but Ramsay I understand will have none of it—as yet.3

Believe me | Yours very faithfully | Alfred R. Wallace

1
CD’s Forms of flowers was published in mid-July 1877 (CD’s ‘Journal’ (Appendix II)).
2
CD and Wallace had long debated CD’s theory of sexual selection as described in Descent (see, especially, Correspondence vols. 15 and 16). Wallace included his objections to the theory in a chapter titled ‘The colour of animals and sexual selection’ in his book Tropical nature and other essays (A. R. Wallace 1878). He published an earlier version in his two-part paper ‘The colours of animals and plants’, in Macmillan’s Magazine in September and October 1877 (see A. R. Wallace 1877, pp. 398–408). Wallace argued that bright coloration occurred as a matter of course in the process of development of different species and especially as a signal of vitality in males; female coloration was often muted for the sake of protection. Females, in his view, chose or more likely submitted to the most vital and persistent males, who only happened to be the most brightly coloured.
3
In two papers in the January and July issues of the Quarterly Journal of Science, Thomas Belt argued that during the Glacial Period, ice in the ocean had dammed river outlets from the continents, causing flooding, extinction of some species, and the creation of silt-covered plains (Belt 1877a and 1877b; copies of both papers are in the Darwin Pamphlet Collection–CUL). He read a paper based on the same theory, ‘The steppes of southern Russia’ (Belt 1877c), at the Geological Society of London on 20 June 1877. No comments by Andrew Crombie Ramsay are recorded in the notes on the discussion following the paper. In 1862, Ramsay had put forward the view that lakes could be formed by glacial action (Ramsay 1862).

Please cite as “DCP-LETT-11067,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-11067