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Darwin Correspondence Project

From Charles James Fox Bunbury to Charles Lyell   3 February 18661


February 3rd, ’66.

My dear Lyell

I thank you much for sending me Madame Agassiz’s letter to Mary, which I have read with much curiosity and interest.2 The variety of new fish and other novelties which Agassiz has discovered are not half so astonishing to me as the rapid growth of that country.3 How completely Brazil seems to be revolutionized by the one single agency of steam. Madame Agassiz speaks of the voyage from Para to the Barra de Rio Negro taking five days;4 when the botanist Spruce explored that country, no longer ago than 1850, the voyage from Para to Santorin, which is little more than half way to the Barra, often required a month. 5 Still, I should have more confidence in observations made by men who have been a long time stationary in chosen spots, like Bates and Wallace and Spruce, than in those made at steam pace.6

Agassiz’s observation on “glacial phenomena,” in Brazil are certainly very astonishing indeed; so astonishing that I have very great difficulty in believing them.7 They shake my faith in the glacial system altogether;—or perhaps they ought rather to shake the faith in Agassiz. They seem to threaten a reductio ad absurdum of the whole theory. If Brazil was ever covered with glaciers, I can see no reason why the whole earth should not have been so. Probably the whole terrestrial globe was once “one entire and perfect icicle.”8 Seriously,—to answer your questions;—there is nothing in the least northern, nothing that is not characteristically Brazillian, in the flora of the Organ mountains.9 I did not myself ascend any of the peaks, but Gardner did, and made very rich collections, of which he has given an account in Sir W. Hooker’s Journal, and more compendiously in his volume of Travels.10 The vegetation consists of very curious dwarfish forms of those families and genera which are characteristic of tropical America, and especially of Brazil; together with representatives of some other groups which are widely diffused, but by no means northern. So also the vegetation of the table lands has many peculiar forms, but is composed mainly of under-shrubby and herbaceous species, of the same families and genera which in the forests appear as trees and tall climbers.11

Certainly, IF Brazil was ever covered with glaciers it seems to me certain that the whole of the tropical flora must have come into existence since. I also think it clear, on the same IF, that the absence of “glacial action” from Southern Europe must be due to some other cause than climate.12

Again, to answer your last question.— Brazil (I speak not merely of the small part which I saw, but of what I have read of, and I have read a good many books of travels in that country), seems to be very deficient in lakes, with the exception of lagoons (“broads” they would be called in Norfolk), on the coast; of these there are plenty, but they are evidently formed in the same way as the Norfolk broads, by the natural damming up of the outfall of the abundant waters. Where I travelled, in the higher lands of the interior, the running streams were absolutely innumerable, but scarcely so much as a permanent pond to be seen.13

Many thanks to dear Mary for her kind message.14 With much love to her, believe me ever

Your affectionate friend | Charles J. F. Bunbury

I think Joseph Hooker will be as sceptical as myself about the glaciation of Brazil.15


This letter was apparently sent by Lyell to CD (see the postscript to the letter to Charles Lyell, 7 February [1866]).
Bunbury refers to Elizabeth Cabot Cary Agassiz and Mary Elizabeth Lyell. The letter has not been found, but an extract was apparently also sent to CD (see letter to Charles Lyell, 7 February [1866] and n. 2).
Bunbury refers to Brazil, where Louis Agassiz was leading a scientific expedition; Agassiz planned to challenge CD’s transmutation theory with the results of a survey of the fish of the Amazon river (see letter to Fritz Müller, 11 January 1866 and n. 10). At Pará (see n. 4, below), during a single week in 1865, Agassiz had identified sixty-three species of fish, a greater number than had previously been recorded in the Amazon basin as a whole (J. L. R. Agassiz and Agassiz 1868, p. 150). By the end of the expedition, Agassiz had identified about 1800 new species of fish (Marcou 1896, 2: 155).
On the impact of railways, industrial engines, and steam navigation on Brazil in the latter part of the nineteenth century, see, for example, Dean 1995, pp. 204–10. Pará is a city in Brazil, near the mouth of the Amazon river; the Barra de Rio Negro is apparently the place where the Rio Negro joins the Amazon river near Manaus (Columbia gazetteer of the world, s.v. Rio Negro). The journey from Pará to Manaus could be made by steamer in five days in 1866, though Agassiz planned to allow longer for the journey, so that he could carry out scientific work (J. L. R. Agassiz and Agassiz 1868, p. 145; see also n. 6, below).
Bunbury refers to Santarém, on the banks of the Tapajós river at its influx into the Amazon (Columbia gazetteer of the world); Richard Spruce made the 474-mile journey from Pará to Santarém between 10 October and 19 November 1849 (Spruce 1908, 1: 54–76).
Henry Walter Bates and Alfred Russel Wallace undertook a joint expedition to the Amazon between 1848 and 1850 (A. R. Wallace 1853, Bates 1863). Spruce published numerous papers about his botanical expedition to the Amazon in the Journal of Botany between 1850 and 1855. Agassiz’s expedition left Pará on 20 August 1865 and arrived at Manaus on 4 September (J. L. R. Agassiz and Agassiz 1868, pp. 143, 152–85).
Evidently the letter from E. C. C. Agassiz to M. E. Lyell (see n. 2, above) had contained information on Louis Agassiz’s observations of glacial action in Brazil. Before arriving in Brazil, Agassiz had lectured on the possibility that the Amazon basin had been formed by glacial action (J. L. R. Agassiz and Agassiz 1868, p. 15). The evidence he subsequently reported of former glacial action in the Amazon basin is presented in J. L. R. Agassiz and Coutinho 1868. The accumulation of such evidence in the closing months of 1865 is reported in J. L. R. Agassiz and Agassiz 1868, pp. 69–70, 86–97, 99–101, 250. For more on Agassiz’s controversial claims of former glaciation in Brazil, see Brice and Figueirôa 2001.
In the late 1830s, Agassiz had pioneered the concept of a former ice age that had affected part of the globe (see, for example, Lurie 1960, pp. 94–106). In 1840, Lyell and others came to accept Agassiz’s glacial theory (see, for example, Lurie 1960, p. 100), although Lyell subsequently rejected Agassiz’s views (Boylan 1998). Through his observations in the Amazon basin in 1865 and 1866, Agassiz sought to demonstrate that the entire earth had been frozen during the ice age (J. L. R. Agassiz and Agassiz 1868, pp. 399, 425; see also Brice and Figueirôa 2001, pp. 162–70). This represented a challenge to CD’s transmutation theory by denying the possibility that plants and animals living after the ice age were the descendants of ones living before it (see, for example, Lurie 1960, pp. 353–4). It also challenged CD’s theory of the geographical distribution of species, as presented in chapters 11 and 12 of Origin, in which CD argued that the tropics and the wider equatorial area had been a retreat for temperate species during the ice age (Origin, pp. 376–9). For an account of the development of glacial theory during the early to mid Victorian period, see Rudwick 1969 and Imbrie and Imbrie 1979, pp. 19–46.
The Serra dos Orgãos, or Organ Mountains, are a coastal range in central Rio de Janeiro state (Columbia gazetteer of the world). Lyell’s evident interest in the ‘northern’ origin of species there apparently relates to CD’s theory of geographical distribution and the retreat of temperate species to the equatorial region during the ice age (see n. 8, above). In 1841, Bunbury had communicated information on the flora of Brazil to the Linnean Society (Proceedings of the Linnean Society of London 1 (1849): 108–10).
Between 1842 and 1848, George Gardner contributed a number of papers on the flora of Brazil to the London Journal of Botany; these included Gardner 1843 and 1845, a detailed description of plants on the Organ mountains. The London Journal of Botany was edited by William Jackson Hooker between 1842 and 1848 (Allan 1967, p. 143). In Gardner’s Travels (Gardner 1846a), the accounts of the flora of the Organ mountains are on pp. 40–6, 63–70, 527–31. A further account appeared in Gardner 1846b.
Species common to the pasture lands (described by Bunbury as tableland) at the foot of the Organ mountains and those of the adjacent virgin forests are enumerated in Gardner 1846b, p. 275–9. Bunbury visited the area in 1833 (F. J. Bunbury ed. 1891–3, Early life, p. 90).
Bunbury apparently considered that, if Agassiz’s claims that there had been glaciers in Brazil were correct, it would follow that southern Europe had also been glaciated, even though the physical evidence was lacking. Various natural agents that could have destroyed such evidence in Europe had been considered by Lyell in letters written to Leonard Horner from Switzerland and Italy in 1857 (K. M. Lyell ed. 1881, 2: 249–72). Lyell later noted that evidence gathered in Europe and North America suggested that former glaciation had extended ten or more degrees further south in North America than in Europe (C. Lyell 1867–8, 1: 298).
See also F. J. Bunbury ed. 1891–3, Early life, pp. 84–100, 113–42.
Mary Elizabeth Lyell was the sister of Bunbury’s wife, Frances Joanna Bunbury.
Bunbury refers to Joseph Dalton Hooker. See letter to Charles Lyell, 15 February [1866].


Allan, Mea. 1967. The Hookers of Kew, 1785–1911. London: Michael Joseph.

Bates, Henry Walter. 1863. The naturalist on the River Amazons. A record of adventures, habits of animals, sketches of Brazilian and Indian life, and aspects of nature under the equator, during eleven years of travel. 2 vols. London: John Murray.

Columbia gazetteer of the world: The Columbia gazetteer of the world. Edited by Saul B. Cohen. 3 vols. New York: Columbia University Press. 1998.

Dean, Warren. 1995. With broadax and firebrand: the destruction of the Brazilian Atlantic forest. Berkeley, Calif., and London: University of California Press.

Gardner, George. 1843. Contributions towards a flora of Brazil. II. Plants from the Organ Mountains. London Journal of Botany 2: 329–55.

Imbrie, John and Imbrie, Katherine Palmer. 1979. Ice Ages: solving the mystery. London and Basingstoke: Macmillan Press.

Lurie, Edward. 1960. Louis Agassiz: a life in science. Chicago: University of Chicago Press.

Lyell, Charles. 1867–8. Principles of geology or the modern changes of the earth and its inhabitants considered as illustrative of geology. 10th edition. 2 vols. London: John Murray.

Marcou, Jules. 1896. Life, letters, and works of Louis Agassiz. 2 vols. London and New York: Macmillan and Co.

Origin: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. By Charles Darwin. London: John Murray. 1859.

Rudwick, Martin John Spencer. 1969. The glacial theory. History of Science 8: 136–57.

Spruce, Richard. 1908. Notes of a botanist on the Amazon & Andes, being records of travel … during the years 1849–1864. Edited by Alfred Russel Wallace. 2 vols. London: Macmillan and Co.

Wallace, Alfred Russel. 1853. A narrative of travels on the Amazon and Rio Negro, with an account of the native tribes, and observations on the climate, geology, and natural history of the Amazon valley. London: Reeve.


Discusses Louis Agassiz’s theory of the glaciation of Brazil.

Letter details

Letter no.
Bunbury, C. F. J.
Charles Lyell, 1st baronet
Source of text
F. J. Bunbury ed. 1891–3, Later life 1: 134–6.

Please cite as

Darwin Correspondence Project, “Letter no. 4995F,” accessed on 6 May 2021,

Also published in The Correspondence of Charles Darwin, vol. 14