Darwin's list of fossil wood specimens from the Beagle
These notes, now kept in the Natural History Museum (London), identify numbered specimens of fossilized wood collected by Darwin on the voyage of the Beagle (1831-1836). Darwin gave the notes and specimens to Scottish botanist Robert Brown (1773-1858), Keeper of the Botanical Department of the British Museum.
The notes were apparently composed at different times because the spellings of 'Chili' and 'Chile' are used, and the style of separating the specimen numbers from the descriptions varies between the two folios.
The notes refer to red, green, yellow and white paper. These colours refer to coloured-paper labels Darwin attached to his specimens. The colours indicated which thousand was to be placed before the actual three-digit number. As Duncan Porter explained in Beagle plants, p. 152, regarding one of Darwin's specimen notebooks:
Inside the front cover of the notebook Darwin wrote:
This is a note to the user that a specimen with a yellow label bearing the number 645 is actually number 3645.
White was 0-999.
Brown examined the specimens sometime between the end of March to mid-May 1837. (See Correspondence vol. 2, letter to J. S. Henslow, 18 [May 1837]).
The fossil wood specimens included the famous fossilized trees Darwin discovered in the Andes in 1835. (See the Coquimbo notebook, p. 36. ) Darwin described the discovery, and Brown's description of the trees, in Journal and remarks, p. 406:
In the central part of the range, at an elevation probably of seven thousand feet, on a bare slope, I observed some snow-white projecting columns. These were petrified trees, eleven being silicified, and from thirty to forty converted into coarsely-crystallized white calcareous spar. They were abruptly broken off; the upright stumps projecting a few feet above the ground. The trunks measured from three to five feet each in circumference. They stood a little way apart from each other, but the whole formed one distinct group. Mr. Robert Brown has been kind enough to examine the wood: he says it is coniferous, and that it partakes of the character of the Araucarian tribe (to which the common South Chilian pine belongs), but with some curious points of affinity with the yew.
The trees are also described in a letter to John Stevens Henslow ([Extracts from letters addressed to Professor Henslow], p. 28). For a modern re-appraisal of the trees and the site discovered by Darwin, see Revista.
In Volcanic islands, p. 140, Darwin discussed impressions of leaves from Tasmania, which were also described by Brown:
Behind Hobart Town there is a small quarry of a hard travertin, the lower strata of which abound with distinct impressions of leaves. Mr. Robert Brown has had the kindness to look at my specimens; he informs me that there are four or five kinds, none of which he recognizes as belonging to existing species. The most remarkable leaf is palmate, like that of a fan-palm, and no plant having leaves of this structure has hitherto been discovered in Van Diemen's Land. The other leaves do not resemble the most usual form of the Eucalyptus, (of which tribe the existing forests are chiefly composed,) nor do they resemble that class of exceptions to the common form of the leaves of the Eucalyptus, which occur in this island.
Otherwise it seems Brown never published descriptions of Darwin's fossil wood specimens. The specimens are now in the Department of Palaeontology, Natural History Museum (London).
For a detailed account and identifications of the fossil notes see: B. A. Thomas, 'Darwin and plant fossils'. The Linnean 25, No. 2 (April 2009): 24-42. (online pdf) [The references to and quotations from Darwin's Beagle field notebooks in this article are from the transcriptions published on Darwin Online, although not cited in the references.]
Two other specimens of Darwin's fossil wood are in the Geological Collections of the Oxford University Museum. These consist of: "two pieces of fossil wood, one labelled "Van Diemen's Land. Lower part of the tree", the other "Peru. Petrified wood"." Chancellor et al 1988, p. 198.
Two specimens of thin sections of fossil wood have recently been identified by Howard Falcon-Lang at the British Geological Survey. He kindly sent the following details:
PF7455 This specimen is labeled "Chiloe, C. Darwin Esq".
PF7463 This specimen is labeled "Agate from centre of fossil tree, C. Darwin, from R. Orr".
Darwin, C. R. [List of fossil wood specimens from the Beagle.] Text & image NHM-408865-1001