Charles Darwin's notebooks from the voyage of the Beagle

'Ladies, like mermaids': An introduction to the Galapagos Notebook

Nora Barlow, in her study of the field notebooks, p. 247, stated that 'there is disappointingly little in the Galapagos pocket-books of interest'. Yet when the Galapagos Notebook was first published in full on Darwin Online there was enormous public interest.

A survey of the number of times the texts of the field notebooks have been accessed on Darwin Online in August 2008 showed a massive level of interest in the Galapagos Notebook. All the notebooks had been available online since October 2006, and although there were unexpected differences in the numbers of visits to particular notebooks, few had been accessed more than three thousand times, and five of the notebooks had been accessed less than two thousand times.

By dramatic contrast, the Galapagos Notebook had been accessed over 43,000 times, of which no less than 8,000 visits were in the previous two months. This huge and growing interest in the notebook is mainly because Darwin and the Galápagos are so closely and so famously associated. About one third of the notebook deals with Darwin's visit to the Galápagos in September-October 1835. In many popular accounts the voyage of the Beagle is almost synonymous with the Galápagos Islands. Despite Frank Sulloway's decisive refutation in Sulloway 1982b, it is still widely believed that Darwin 'discovered' evolution on the Galápagos. This belief is constantly reinforced in travel brochures and TV programmes.

The Galapagos Notebook is one of the shortest notebooks.1 It is also currently lost and is, therefore, only available as black and white microfilm images taken in 1969.2 For these reasons - if all else was equal - the Galapagos Notebook would probably be the least interesting notebook. Somewhat paradoxically, however, the fact that we do not know the current whereabouts of the Galapagos Notebook has made it the most accessible notebook because Darwin Online has been allowed to present online images of the notebook taken from the microfilm. This has not been allowed with any other notebook, which are currently only available online as transcribed text.

As van Wyhe's recent research has shown, the belief that the Galápagos are where Darwin became an evolutionist is a mid-20th century version of Darwin's life. If anywhere can be said to be the geographical source of Darwin's doubting the fixity of species it is the South American mainland, where he had been struck by the key relationships between fossil and recent mammals and between the various 'representative' species of living mammals and land birds such as the rheas. These crucial observations, combined with his study of Lyell's Principles, prepared Darwin's mind for a break with received wisdom on species origins, as he himself stated in the opening lines of Origin and as he explained with great clarity in the introduction to Variation 1: 9ff.

There were, however, many other observations made by Darwin during the voyage which contributed to his eventual development of evolutionary theory, including, for example, the mammals of the Falklands and Ascension Island, the absence (with a few minor exceptions) of indigenous mammals on New Zealand, the antlion of Australia and the dramatic differences between Englishmen and Fuegians. See introductions to the Rio, B. Blanca, Santiago and Port Desire Notebooks. Many scholars have discussed these and other key lines of evidence, for example Browne 1995, Herbert 2005, Hodge 1983, Keynes 2004, Kohn 1980, Sloan 1985 and Sulloway 2002.

It remains the case, however, that Darwin's famous note on the 'stability of species' (discussed below), written in June or July 1836 in his 'Ornithological notes', was a result of considering the distribution of species and varieties of Galápagos land birds and tortoises. It is also true that Darwin's retrospective Journal entry for July 1837 attributes great importance to the facts of the Galápagos (though not to the experience of his visit), p. 13 recto:

Had been greatly struck from about month of previous March on character of S. American fossils — & species on Galapagos Archipelago. — These facts origin (especially latter) of all my views.

The connection between Darwin and the Galápagos was strong long before he became famous for his theory of evolution by natural selection. From 1839-1859 Darwin was known to the general public primarily as a scientific travel writer. Hence it was Darwin who introduced most readers to the exotic Galápagos. His Journal of researches remained popular well into the 20th century. Only decades after his death did the story of a eureka-like discovery of evolution while on the Galápagos emerge. After further decades of association with the exotic islands and their association with the birth of the theory of evolution, it seems the connection will endure for the foreseable future.

In 1980 John Chancellor (1925-1984) selected the Galápagos as the setting for his first of two paintings of the Beagle. See Chancellor 2008. It is also why several authors have reconstructed Darwin's excursions in the archipelago in far more detail than anyone has attempted for any other part of the voyage e.g. Armstrong 2004, Estes et al. 2000, Herbert 2005, Sulloway 1984.

As Armstrong 2004 has stressed, in terms of Darwin's intellectual development it was fortuitous that he visited the Galápagos having just left the South American mainland. By February 1835 he had become convinced that species had 'life spans' and so had already made a break from Lyell on the issue of the 'death' of species. By the time the Beagle sailed for the Galápagos in September Darwin had not only rejected Lyell's explanation for coral atolls but was also ready to challenge the older man's rejection of any natural 'birth' of species and his prediction that islands would be 'foci of creation'.

Darwin explained in his Autobiography, p. 118, written in 1876, how:

During the voyage of the Beagle I had been deeply impressed…by the South American character of most of the productions of the Galapagos archipelago, and more especially by the manner in which they differ slightly on each island of the group; none of these islands appearing to be very ancient in a geological sense.

The fact that varieties or species of organisms with apparently close links, not only to each other but also to mainland species, appeared to be confined to particular islands in the Galápagos was a big puzzle for Darwin. He could not fit this into the theistic view of perfect adaptation to environment which he had imbued from his teachers such as Henslow and Lyell. He was also struck by the absence of insects which would certainly have flourished in the well-vegetated uplands, further undermining his faith in Lyell's view that species would be created where the conditions would suit them. Darwin had already observed the striking similarities between the different 'allied' mainland species such as Myothera, occupying differing habitats, for example on either side of the Andes. It was not until he visited the Galápagos, however, that he saw how isolation might provide a mechanism for forcing differences between varieties or species in similar habitats.

Eight or nine months after the Beagle's visit to the Islands, probably just after his visit to St Helena, Darwin was drafting his 'Ornithological notes' and began to see how the Galápagos land birds had actually gone one step further than diverging from their presumed mainland ancestors. They had, it seemed, started to diverge from each other within the archipelago itself, because the chances of three varieties of mockingbirds migrating exclusively to three separate islands beggared belief. John Gould's confirmation, in early 1837, of the American character of the birds and of their specific differences, struck Darwin profoundly. Here at last, along with the facts he learned from Owen about his South American fossils, was proof that adaptation was relative and that descent with modification was the best explanation for the observed patterns.

In the Origin, p. 406, Darwin ended his discussion of the biogeography of oceanic islands with one of his key points about evolution by natural selection:

The relations just discussed … [including] the very close relation of the distinct species which inhabit the islets of the same archipelago, and especially the striking relation of the inhabitants of each whole archipelago or island to those of the nearest mainland, are, I think, utterly inexplicable on the ordinary view of the independent creation of each species, but are explicable on the view of colonisation from the nearest and readiest source, together with the subsequent modification and better adaptation of the colonists to their new homes.

At first glance there appears to be almost nothing in the Galapagos Notebook which can be interpreted as a glimmer of understanding of speciation in the Galápagos. There are, however, clear indications that Darwin did quickly perceive the 'American-ness' of the land birds and immediately asked himself if the plants of the archipelago might — if he only knew enough botany — reveal the same links with the mainland.3 The notebook also contains Darwin's first reference to the finches which were later named after him by Lowe 1936. The finches' beaks are still of great scientific interest today and are routinely cited as a beautiful example of adaptive radiation (Grant 1984). There are many other examples of 'evolution in action' to be seen in the Galápagos, several of which were used by Darwin himself as evidence for his theory, and it is largely for this reason that the islands are today one of the world's great travel destinations.

So the Galapagos Notebook does not provide any clear evidence of Darwin's 'conversion', but this actually brings us closer to understanding how Darwin came to a new view of nature. Gradually during the voyage, and not by any 'eureka' revelation, Darwin synthesised all that he had seen with what he had read and discussed with others and out of this mix began to see a natural explanation for the otherwise mysterious 'birth' or appearance of new species. In the years following the voyage he was able to use his discoveries to build new theories for a whole range of geological phenomena, of which the origin of coral reefs is by far the most elegant and ambitious. On this foundation he went on to construct a new theory for the origin of species, and it is far from a co-incidence that he thought of calling his first attempt at a diagram of evolution 'the coral of life', Notebook B, p. 25. If Darwin ever did have 'eureka' moments they were his reading of Malthus in September 1838, which made him realize the effects fo selective survival of superfecundity, thus revealing a driver for natural selection, and the 'the very spot in the road' in the mid 1850s when he suddenly discovered the principle of divergence (Browne 1995).

Summary of the notebook

The Galapagos Notebook is a small, square notebook, apparently covered in red leather, with 'Galapagos. Otaheite Lima' written on the label on the front.4 Although there is only the microfilm to work from, plus a photo of the front cover in Dobson 1959, it is obvious that the Galapagos Notebook is Type 5, as are all of the last five notebooks used on the voyage. There are thirty-four pages at the front of the Galapagos Notebook, of which two appear to be excised, plus sixty-six at the back.

The March 1835 entries are on the first seven front pages and perhaps the first ten back pages, although none of these early back pages is dated. The March entries relate to Darwin's trip from Valparaiso to St Jago in advance of his Andean traverse. These merge into field notes from Peru and some rather more 'theoretical' notes which suggest an interesting relationship between this notebook and the Santiago Notebook, which Darwin was using at about this time and which became the main repository for his theoretical musings. As is obvious from the 'Birloches' note, see below and introduction to the Santiago Notebook, Darwin had the Galapagos Notebook with him on his Andean traverse, unless he left it with Caldcleugh for safe keeping in St Jago and picked it up on his way back around 8 April. As was pointed out in the introduction to the Santiago Notebook, therefore, Darwin was using the St. Fe Notebook as his main notebook for the traverse but may also have had the Santiago Notebook and the Galapagos Notebook with him, so all three notebooks are interrelated and close correspondences between them are to be expected.

The next few front pages date from late July and are again partly of a 'theoretical' nature. 'Reached Lima' on p. 17a is unambiguously from 29 July, so there is a gap in use of the intervening pages of about three months. The next back pages are almost impossible to date although they too seem to relate to Peru in July. The Lima front pages extend to about p. 28a at which point Galápagos notes commence and continue until four pages from the end.

The Galápagos field entries continue on the back pages after various probably undateable notes. The archipelago takes us through the second half of September and the first half of October until the final note registers Darwin's sighting of Halley's Comet on 18 October on p. 50b.

The last four front pages seem to be concerned with theoretical topics of the kind discussed in the Santiago Notebook. The entries seem to relate to South America and the Pacific and they date from the Beagle's passage from the Galápagos to the Low Islands [Tuamotus] in late October or early November. The next dated note is 18 November in Tahiti and Darwin's visit to this Island ends the notebook on p. 66b.

What follows is a detailed analysis of the notebook, divided into 'Chile', 'Lima', 'Galápagos' and 'Tahiti' sections, with the proviso that these are not clear cut divisions. There are jottings from before and after each place and the inside covers were used in several places at different times.

The inside front cover of the notebook is largely illegible on the microfilm where oil from the leather cover has permeated the paper, but 'Lima August 4th 1835' can be made out written perpendicular to the spine and there are a few jottings including 'Amblyrhyncus', the famous Galápagos marine iguana. The word 'Benchuca', being the bug which bit Darwin on 26 March. Sadly the first two front pages are excised. The inside back cover has 'Anchored 30th at Blonde Cove' and refers to Banks' [Tagus] Cove on Albemarle [Isabela] Island in the Galápagos where the Beagle anchored on 30 September.

Chile, March 1835

The back pages commence on p. 1b with names of places perhaps to be visited on the coast between Valparaiso and Coquimbo. These are followed by jottings of provisions to take on an expedition and on p. 4b of people's names, equipment and pieces of intelligence. The note 'Letters home' followed by at least eight names suggests Darwin reminding himself to attend to his correspondence. He wrote to several of these people at roughly this time.5 The lists which are fascinating but very difficult to date continue on the back pages up to p. 17b after which entries clearly relate to the Galápagos. There is a general correlation in the subject matter between these earlier front and back pages and since the former can be dated it is best to consider them in more detail, noting where the same subject crops up in both front and back pages.

The surviving front pages begin on p. 3a with more jottings including the question 'Aconcagua active. When? Before [Birkbeck]??' apparently answered by '19th of January'. The same occurrence is mentioned on p. 15b just before a remarkable note of the eruption of 'Cosiguina [that is Coseguina in Nicaragua] at 6 &1/2 in the morning of 20th'. Darwin seems to have heard that Aconcagua, the highest mountain in the world outside the Himalayas, erupted on 19 January 1835, and he referred to this in his 1840 paper on volcanoes and earthquakes as an example of how three Andean volcanoes all erupted at more or less the same hour one month before the great Concepción earthquake. (Darwin 1840) FitzRoy, who measured the height of Aconcagua, stated in his short paper about the mountain in 1837 that it was 'a volcano in the Cordillera of the Andes' and that it was active 'at intervals', all of which seems reasonable until one discovers that the Smithsonian Institution does not recognise Aconcagua as a volcano! (FitzRoy 1837) In fact a careful reading of Darwin 1840 shows that he was uncertain that the reports of Aconcagua’s eruption could be relied on and in DAR36.442-443 he noted that it was not always easy to identify these mountains when viewed from afar.

We are grateful to John Woram for the suggestion (personal communication) that Birkbeck is Darwin's misspelling of Byerbache, the name of 'a resident merchant' in Valparaiso, who Darwin recorded in the 1840 paper had informed him 'that sailing out of the harbour one night very late, he was awakened by the captain to see the volcano of Aconcagua in activity' (Darwin 1840, p. 611). Woram has also made the helpful suggestion that Byerbache could be Edward Beyerbache, U.S. Consul in Talcahuano. We are, furthermore, grateful to Sergio Zagier for suggesting that Byerbache had actually misinformed Darwin and that it was more likely to have been the nearby true volcano Tupungato which erupted.

A related pair of entries on p. 6b and p. 8b refer to a Mr Croft's clock having stopped at about fifteen minutes to noon, which apparently corresponded to ten minutes to noon at St Jago. This was no doubt the time of the Concepción earthquake on 20 February. Mr Croft is also credited on p. 4b in connection with a 'back bone of Cetacea'.

There is a reference on p. 3a to a Mr Cood, whose name also crops up on p. 6b with a note about a 'letter to Iquique', and citation of an 1826 Peruvian map. This is followed on p. 4a by the first true field notes, dated 14 March, when Darwin 'Started for St Jago [from Valparaiso] — in a Birloches or gig'. There is a brief account of the geology then 'Slept at the foot of the Prado & reached St Jago by 9 oclock on Sunday morning (15th)', p. 7a, implying that Darwin had made an early start. In his Beagle diary he called the mountain the Rado.

It is at this point that the notebook seems to have been put aside until late July, although some of the back pages may date from the gap months. In these months Darwin completed his classic circuit to Mendoza and back, for which he used the St. Fe Notebook, then the Coquimbo Notebook for May, the Copiapò Notebook for June and the Despoblado Notebook for July, with the Santiago Notebook for theoretical work. The middle three of these make up the 'expedition no 8 trilogy'.

Lima, July-August 1835

The reference on p. 7a to 'Guancavelica' is to Huancavelica, about 300km southeast of Lima, and 'Caneta' is Cañete. The place is also mentioned on p. 6b supporting the view that Darwin was using both ends of the notebook at this point. It is impossible to date the entry but it was probably written in Callao, where the Beagle arrived on 19 July, remaining there for seven weeks. Due to the unstable political climate Darwin spent most of August on board writing up his Beagle diary and 'Geological notes about Chili', including presumably his 'Recapitulation and Concluding Remarks' (DAR41.23-39). FitzRoy, however, having returned aboard H.M.S. Blonde on 9 August, resided in Lima.

On p. 8a Darwin recorded a lizard and a frog but he does not seem to have collected specimens of these. On a 'Wednesday' on p. 8a Darwin recorded the barometric altitude of some shells, and it is a reasonable guess that the date was 21 July. This is slightly at variance with Barlow's 1945, p. 244 dating of p. 12a as 19 July. The notes relate to Darwin's fieldwork on the island of San Lorenzo, 'the only secure walk' according to his Beagle diary that he was able to take in that vicinity. These notes follow on from p. 45b in the Despoblado Notebook. Page 9a in the Galapagos Notebook is dated 'Thursday' which must then be 23 July. The next three pages, which relate to volcanoes, earthquakes and tsunamis are impossible to date more precisely than before 29 July. The note at the top of p. 12a that 'The Beagle called in on the 23 April. Valparaiso' is obviously retrospective. That was an interesting event as it was then that Darwin told FitzRoy of his promotion to Post Captain.

The entry on p. 13a starts with 'Casma, Huaraz', which are two places reported to Darwin by a civil engineer in Lima called Mr Gill, between which this gentleman had found evidence of changes in irrigation having forced the abandonment of a settlement (see Beagle diary for 4 April). The entry continues with a field note, which must date to around 21 July, from San Lorenzo and the reference on p. 14a to salt in the sandstone on the island occurs in a footnote in South America, p. 48. The entry 'Petrified wood, Gypsum & Salt' on p. 10b seems to refer to this, providing the first reasonably solid dating for the back pages.

The question 'Was Bellavista destroyed in 1846' on p. 15a is a mistake referring to the terrible Lima earthquake of 1746. This is also mentioned on p. 12b. The 'Cruikshank' noted on p. 15a is obviously the 'Mr. A. Cruckshanks' reported by Lyell 1833, p. 130, to have found sea pebbles 200m above sea level at Callao. Darwin referred to Cruckshanks in South America (p. 51) as providing yet more excellent evidence of dramatic elevation, some of it in historical times. See introduction to the Copiapò Notebook.

Pages 12b to 17b could date to almost any time from late July to mid September. In some ways perhaps the most important note is 'Mem Dessaline D'Orbigny excellent memoir' on p. 14b as one of only three field notebook references to the great French naturalist who subsequently made a major contribution to Darwin's South America. The note shows that Darwin had seen Blainville 1834, the early results of d'Orbigny's research in South America and this is confirmed by Darwin's letter to Henslow of 12 August (Correspondence vol. 1, p. 462).

On p. 16a Darwin made an unusual reference to an article in 'No 32 Magazine of Natural History' which is not listed in the Correspondence (vol. 1) as being on the Beagle so it is possible that someone, perhaps the author of the article Charles Waterton (1782-1865) sent him a copy. The article (Waterton 1833) and others in the same volume discussed the smelling powers of birds and this was a subject of great interest to Darwin. At a garden in Lima he carried out an experiment, described in his 'Ornithological notes', p. 244, and published in Birds, pp. 5-6, which appeared to show that Condors found carrion by sight rather than smell. This observation has since been confirmed, see Steinheimer 2004, pp. 307-8. Field notes from Lima resume on p. 17a with 'Reached Lima. Wednesday morning by coach'. In his Beagle diary Darwin recorded that this was on 29 July and that he 'spent five very pleasant days' at Lima which was about 12 km from Callao. Lima, founded in 1533 by Pizzarro after conquering the Incas, is likely to have been a great attraction for Darwin as being the only place he visited which was also visited by Humboldt, who visited in 1802.

The notebook entry is worth quoting in full:

road, uninteresting. not like Tropical country — many ruined houses, owing to long state of anarchy:

Lima, passed gate; wretched filthy, tropical smell, ill paved — splendid looking town, from number of churches painted, like stone cane as are upper stories. But everything exceeded by ladies, like mermaids, could not keep eyes away from them: — remarkably mongrel population.

There is a hiatus in Syms Covington's Journal for the period February to November 1835, but he has left us with eight watercolours of the Limenian ladies, one of which is reproduced in Keynes 1979, p. 289.

Darwin 'Rode to Merchants home to sleep; nice garden & large house only 20 £ per annum!!' (p. 18a). Presumably the next day (the 30th) 'Before breakfast' Darwin 'rode to neighbouring hills' but experienced the disadvantage of visiting Peru during the garua season:

I dare say view would be very pretty, but ceaseless mist & gloom: Have no idea of merits of view; exception from day, from S Lorenzo — Clouds clearing away leaving strata, always give a majestic air to landscape

That evening Darwin 'Dined with Consul General' Belford Wilson (1804-1858) and had a 'very interesting evening'. Wilson had been Simon Bolivar's (1783-1830) aid de camp and Darwin records in his Beagle diary that Wilson knew South America 'right well'. He had suffered the indignity, a few years previously, of having all his clothes stolen by robbers who cried out patriotically 'Vive la patria off with your jacket' (p. 26a).

Presumably the geology notes which follow on pp. 20a-23a were made the following day (the 31st), and the 'Peruvian geologist' mentioned on p. 20a is the 'M. Riveiro' on p. 22a. As usual Darwin noted any shells at high altitudes (p. 24a) then on p. 25a 'August 3rd returned' to the Beagle. He observed the 'Condors flight, close wing — remarkable motion of head & body' which became the beautiful description published in Birds, p. 6.

Galápagos, September-October 1835

In several letters home written at this time Darwin expressed his eagerness to see the Galápagos, largely perhaps because they were virgin scientific territory. To his sister Caroline, for example, he wrote with eager prescience:

I am very anxious for the Galapagos Islands, — I think both the Geology & Zoology cannot fail to be very interesting (Correspondence, vol. 1, p. 458).

Darwin visited four of the islands: Chatham [San Cristóbal] starting 16 September, Charles [Floreana] starting 24 September, Albemarle [Isabela] starting 1 October and James [Santiago] starting 8 October. See Thalia Grant's map in Keynes 2004, pp. 308-9 and Estes et al. 2000 for details.

The first entry on p. 18b is a description of the eel Muroena lentiginosa, spirit specimen no. 1286, Fish, pp. 143-4, collected off Chatham Island. This was probably on 17 September when we know from his Beagle diary that Darwin collected many plants and animals. The notebook had not, therefore, been used since 3 August, the Beagle having 'Sailed from Lima 7th September' (Despoblado Notebook, p. 43b).

The next entry is dated 'Saturday', that is 19 September 1835, and reads 'left our anchorage & stood out to outside of Island, did not anchor'. Darwin made no more entries until the following day: 'Continued to beat to windward high side of island rather greener waterfalls of Water!' (pp.18b-19b). This was Freshwater Bay, and the notebook entry supports the statement by Estes et al. 2000, p. 346 that they could find no evidence that Darwin went ashore there.

The next day, that is 21 September, 'A boat being sent to some distance, landed me & servant, 6 miles from the ship. Where we slept — I immediately started to examine a Black — Volcanic district deserving name of Craterized', pp. 19b-20b. The past tense means that the field notes from the 21st are retrospective. Sulloway 1984, p. 34, provides a fine photograph of the district Darwin visited, where he 'Met an immense Turpin'. He noted that this giant tortoise (Geochelone nigra) 'took little notice' of him and was 'Eating a Prickly Pear — which is well known to contain much liquid', pp. 20b-21b.

Estes et al. 2000 have given a very full account of Darwin's activities on the 21st and have attempted to identify where exactly in the 'Craterized district' he made his detailed observations on the lavas there, which Darwin noted had 'been compared to most boisterous frozen ocean' , p. 21b. He drew two small sketches here, the first showing a wave-like fold in the lava, the other showing hexagonal cooling joints, and he was trying to identify the boundary between two lava streams.

Lavas on oceanic islands are generally of 'basic' composition, that is they have low silica and are not as viscous as so-called 'acid' continental lavas. Thus Galápagos lavas tend to flow freely rather than cause explosive eruptions like their Andean counterparts. For an excellent account of Galápagos geology see Simkin 1984. In his geological diary, DAR37.768, Darwin discussed the apparently quite fresh lavas in the Banks' Cove area where he was on 1 October, and compared them with the Chatham lavas described on p. 21b. In Darwin's classic account of the Galápagos in chapter 5 of Volcanic islands, p. 105, he refined the language used in the geological diary entry so that the final version became one of the most poetic verbal comparisons he ever published:

At Chatham Island, some streams, containing much glassy albite and some olivine, are so rugged, that they may be compared to a sea frozen during a storm; whilst the great stream at Albemarle Island is almost as smooth as a lake when ruffled by a breeze.

Darwin counted 'little less than 100' 'very small' craters, p. 23b, and tried to estimate their average distance apart (p. 24b). He sketched a crater, p. 25b, describing the different types of lava. Today the type he called 'black & glossy' would be given the Polynesian term pahoehoe and the more 'slaggy' type aa. On p. 26b he drew what may be a spatter cone, judging from the size and description on pp. 27b-28b and he noted collapsed lava tubes on pp. 28b-29b.

There follows on p. 30b one of the most important entries in all the notebooks:

The Thenca very tame & curious in these Islds. I certainly recognise S. America in ornithology, would a botanist?

This note contains three key elements. Firstly, there is the observation on the tameness of the 'Thenca', the Spanish name for the mockingbirds. The tameness applied to all the Galápagos animals but was extreme in the case of the 'Thenca', as indeed it still is today. This tameness, which he attributed to the absence of carnivorous mammals on the islands, showed Darwin how animals have to acquire instinctive fear by a process of hereditary learning. Since at this point he may or may not have realised that the Thenca had migrated from the mainland, where mockingbirds are less tame than the Galápagos birds, we cannot know whether he was thinking that they had actually become more tame than their ancestors. Secondly, there is the obvious resemblance between the Chatham (and Charles) 'Thenca' and 'Thencas' and 'Callandras' from the mainland of which he had extensive knowledge. The resemblance could be the result of some mysterious 'halo of creative force' but could also be explained by the birds having migrated to the islands from the mainland. Thirdly, there is the question: does this possibly historical link apply to the plants, as from the presence of cacti such as the prickly pear (Opuntia) it certainly seemed to? Would 'a botanist' be able to confirm this link? It is obvious from Darwin's letter to Henslow written four months later that it was his Cambridge mentor who he hoped would do the confirming (Correspondence, vol. 1, p. 485; see also Porter 1984). As he put it in the less private confines of his Beagle diary entry for 26-7 September:

It will be very interesting to find from future comparison to what district or "centre of creation" the organised beings of this archipelago must be attached.

It is of course desireable to date the 'Thenca' entry, which judging from the reference to 'Finger Point' two pages further on seems to set it firmly on Chatham (Estes et al. 2000, p. 347) on 21-22 September. It is, however, followed by '3/4 of Plants in flower', p. 31b, which is almost identical to wording which occurs in the next island entry in the front pages: 'Big tree — Misseltoe tree on various other kinds - 3/4 plants in flower', pp. 28a. The 'Misseltoe' may be the Phoradendron henslovii, Beagle plants, p. 182, from Charles Island, specimen 3244, indicating that the 'Thenca' note may have been written on Charles, which Darwin was exploring on the 25th, when he met the Vice Governor Nicholas Lawson who told him that he could tell which island a tortoise came from by looking at the shape of its shell. It was believed at the time of the Beagle's visit that the tortoises had been introduced by sailors from the Indian Ocean within the previous few centuries. Darwin was impressed, on later reflection, by the rapid divergence of the tortoise shells implied by Lawson's claim. Apart from the Falkland foxes, this was the only case he had encountered of different varieties on different islands in an archipelago.6

In attempting to date the 'Thenca' entry, it appears likely that the tell-tale phrase is 'in these Islds'. Darwin would probably not have used that phrase if he had only visited one island, so we conclude that he wrote the note on Charles and that he assumed the 'Thenca' was the same bird on both islands. This is contrary to the view of Herbert 2005, p. 313, who places the entry on Chatham.

In his Zoology notes, p. 341, written after leaving the Galápagos in late October, Darwin reflected on the notebook entry and made the following observations concerning the mockingbirds:

This birds [sic] which is so closely allied to the Thenca of Chili (Callandra of B. Ayres) is singular for existing as varieties or distinct species in the different Islds. I have four specimens from as many Isds. These will be found to be 2 or 3 varieties.— Each variety is constant in its own Island.—…This is a parallel fact to the one mentioned about the Tortoises.

This Zoology notes entry shows clearly that Darwin was now confident about the link between the islands' land birds and those of the mainland which he knew so well. He was now seeing, however, something which had not occurred to him before: that the mockingbirds might be even more divergent than the tortoises, with varieties or distinct species apparently confined to particular islands. For the moment this was an anomaly not easily fitted with received wisdom and Darwin could not take the matter further. He would have to ponder it until he had another chance to lay out his specimens, which in the event was around the time he was at St Helena in July 1836, when he wrote his famous entry in the 'Ornithological notes', pp. 73-4:

In each Isd each kind is exclusively found: habits of all are indistinguishable…When I see these islands in sight of each other, and possessed of but a scanty stock of animals, tenanted by these [mocking] birds, but slightly differing in structure & filling the same place in Nature, I must suspect they are only varieties…If there is the slightest foundation for these remarks the zoology of Archipelagos will be well worth examining; for such facts [would inserted] undermine the stability of Species.

Obviously Darwin needed to wait for an expert ornithologist to determine whether his 'Thencas' were all one species or not. Gould responded by describing three new species from the Beagle specimens. In fact the 'Thencas' of Chatham and Charles are today usually but not always regarded as separate species, Mimus melanotis, Birds, pl. 17, on Chatham only and M. trifasciatus, Birds, pl.16, on Charles only. Sadly M. trifasciatus is now extinct on Charles itself but survives on two nearby islets. The other species described by Gould is M. parvulus, Birds, pl.18, on the other large islands, including Albemarle and James (see Grant 1984). The confirmation by Gould in 1837 that the species from different islands were distinct was of immense importance to Darwin as this did indeed 'undermine the stability of species'. Darwin responded in Birds, p. 64, by stating firmly his belief that M. fasciatus and M. parvulus are species 'as distinct as any that can be named in one restricted genus'. Sulloway 1982c, p. 350, provides photographs of Darwin's specimens of Mimus.

Mimus melanotis from Chatham and James’s Islands, Galapagos. Plate 17 from Birds. Mimus trifasciatus from Charles Island, Galapagos. Plate 16 from Birds. Mimus parvulus from Albemarle Island, Galapagos. Plate 18 from Birds.

Three species of Galapagos mockingbirds.

The field notes are not conclusive with respect to location but the note 'I now understand St Jago Lava' on p. 32b shows that he was looking for signs of 'upheaval' and the reference to 'King Landscape' is suggestive of Charles Island. P.G. King painted a watercolour on Charles Island which is reproduced in Keynes 1979, p. 301. Darwin's comparison between the Galápagos lava fields and craters and the 'Phlegrean fields' and craters of Vesuvius and Etna, which he knew so well from Lyell's accounts, is memorable.

The next page, p. 34b, is also highly important and may be the reason why Brent 1981, plate 9, chose to illustrate it. There is the first reference to 'Lizards' which may be iguanas or lava lizards, followed by 'Black Mud & parasites — Brazil without big trees. Forest. Robinson Crusoe Gross-beakes', p. 34b. The mention of 'Gross-beakes' is the first known explicit recording by Darwin of Galápagos finches and it is fairly clear that he is referring to the exceptionally thick-billed large ground finch named by Gould in 1837 as Geospiza magnirostris, Birds, pl. 36; see Sulloway 1984. The reference to black mud, Brazil and Robinson Crusoe all tally exactly with Darwin's Beagle diary entry for 23-4 September. We are grateful to Frank Sulloway for the suggestion that the 'Feast' was probably the small boy's dinner of Galápagos doves, Zenaida galapagoensis, see Birds, pl. 46, which Darwin explicitly said was on Charles in his retrospective Beagle diary entry for the 28th.

Page 43b of the Galapagos notebook with Darwin’s first record of Galapagos finches.

The birds listed on pp. 28a-29a 'Duck male Bitterns 2 female Heron female' may be next in date sequence since they precede 'Craterized Point — Perfect cones — subsequent to streams' which seems to fit exactly with the Beagle diary report for 26-27 September. The duck is almost certainly 3299 Poecilonitta bahamensis, Birds, p. 135, the bitterns 3300 Nycticorax violaceus, Birds, p. 128, and the heron 3296, Zoology notes, p. 413. The listing of these specimens as from James Island in Zoology notes is incorrect.

The next entry on p. 29a is clearly for 29 September as the Beagle rounded the southern end of Albemarle and Darwin got his first view of Narborough [Fernandina] which he declared 'Desolate'. He likened Albemarle to a 'continent built of big old Volcanos' and it is clear from Volcanic islands that he was deeply impressed by the northwest-southeast alignment of the volcanoes on this island.

Geospiza magnirostris from Charles and Chatham Islands, Galapagos. Plate 36 from Birds.
Zenaida galapagoensis from Galapagos. Plate 46 from Birds.

After sunset on 30 September the Beagle 'Reached Blonde cove', then usually called Banks' and today called Tagus Cove. This event which is also mentioned on the inside back cover seems to be the last Galápagos entry in the front pages and so there is an apparent gap in the notes until 12 October. Estes et al. 2000, p. 352 describe Darwin's work at Banks' Cove in great detail and point out that one-third of his geological notes from the islands refer to the area around the cove, an illustration of which appears in DAR44.32 and was eventually published in Volcanic islands, p. 107.

Banks’ Cove, Galapagos. Fig. 13 from Volcanic islands, p. 107.

The bottom of p. 34b and p. 35b at first seem difficult to date or locate precisely other than that they must predate 12 October, the date of the next page. An important element is, however, the observation on p. 34b of a 'Great tendency to nodular or Concretionary structure in all Volcanic Sandstones' which resonates with Darwin's description of structures now called accretionary lapilli at the Beagle Crater near Banks' Cove, which he explored on 1 October. See Estes et al. 2000, p. 354. It therefore seems reasonable to consider p. 35b as Darwin's field notes from Albemarle, but it is certainly possible that they relate to his first few days on James.

In the final element of p. 35b Darwin estimated the area of the archipelago and equated this to the area of 'Sicily & Lipari Isds' and compared the craters to those figured in Scrope's 1825 Considerations on volcanoes.

The Beagle stood round the north end of Albemarle on the 3rd and was therefore in the northern hemisphere for the first time in three and a half years. She then struggled eastwards against the trade winds and currents via Tower (7th) before Darwin was put ashore at James Bay on the 8th, in company with Covington, Benjamin Bynoe, Harry Fuller and two other men. They were there until being picked up on the 17th.

On 9 October Darwin set out for the interior, visiting the hovels where a party of men was employed hunting tortoises. On the 12th Darwin went there again 'Walked up to the Houses — Slept there Eating Tortoise meat By the way delicious in Soup.', p. 36b. According to his Beagle diary 'enjoyed two days collecting' in his 'very green & pleasant' area, p. 36b, which Estes et al. 2000, p. 357, identify as Jaboncillo and which in Darwin's time was thickly covered in endemic Scalesia trees. It was here that Darwin made his classic observations of giant tortoise behaviour, all of which he expanded at length in Journal of researches:

There were 'Extraordinary numbers of Turpin — When drinking bury head above eyes — Will drink when a person is within 2 yards of them about 10 gulps a minute. Noise during cohabitation [copulation] & length of time certain — Eggs covered by sand soil from 4 to 5 in number — require a long time before they are hatched.— Quickness of travelling certain — now said come every three days for Water — Eat Cacti in the dry Islands (pp. 37b-39b).

The next entry on p. 39b shows that he dissected a 'Yellow Iguana', Conolophus subcristatus, see Reptiles, pl. 12, whose intestines were 'full of Guyavitas & some large leaves' and who laid its 'eggs in a hole'. He observed that the 'Caracara habits like Carrancha round Slaughter house kill chickens— run like a cock' (pp. 40b-41b). This was the Galápagos hawk, Buteo galapagoensis, Birds, pl. 2. The final entry is 'Thenca eat bits of meat', p. 40b.

On the morning of 13 October Darwin 'descended highest Crater' in which he collected trachyte lava specimens. For years these rocks, which were described using techniques not available to Darwin by Richardson 1933 and discussed at length by Herbert 2005, pp. 121-6, pl. 4, have unsettled geologists because they are of an apparently anomalously high silica content. In the standard book-length geological description of the Galápagos, McBirney and Williams 1969 went so far as to opine that Darwin's specimen 3268 might not actually be from the islands. Recent work by Pearson 1996 has shown that on the contrary Darwin's specimens are of the highest value as substantiating his then radical approach in Volcanic islands to explaining the fractionation of lavas. Darwin's theory bears comparison with natural selection as a mechanism for sorting out variants, with gravity supplying the force but without of course any analogue of the self-replication process found in living things. Pearson 1996, p. 57 provides photographs of some of Darwin's Galápagos lava specimens.

On returning to Buccaneer Cove Darwin found the freshwater spoiled by the surf, and would have suffered considerably if it had not been for the 'extraordinary kindness of Yankeys' from the whaler anchored in the bay who 'gave us Water', p. 41b.

On 14 October Darwin 'Wandered about Bird collecting' and observing with quite exceptional empathy the iguanas' behaviour:

Shakes head vertically; sea — one no = does hind legs stretched out walks very slowly — sleeps — closes eyes — Eats much Cactus: Mr Bynoe saw one walking from two other carrying it in mouth — Eats very deliberately, without chewing — Small Finc[h] picking from same piece after alights on back — (pp. 42b-43b)

This is the second of only two references to the finches in the notebook. On pp. 44b-45b Darwin recorded the temperature: 77º Fahrenheit in the trade wind, 108º 'On rock out of wind'. On the 16th, Darwin's last full day in the islands, there was no wind at noon and his thermometer placed in the sand shot to 137º, p. 45b.

The remaining field notes from the island must date from the afternoon of the 16th. They indicate one final trek into the interior: 'at highest central Crater'. Darwin noted that one side of the 'perfect' crater was lower, due to ash piling up more on the lee side, and that it was '1/3 of mile diameter', p. 46b. He included a section on the striking asymmetry of the Galápagos craters in Volcanic islands, pp. 113-4. The description in the notebook matches that in the geological diary (DAR37.770) quoted by Estes et al. 2000, p. 358. Darwin's final observations of the land iguana are worth quoting in full:

Iguana digs tail motion slow — appear = same stupid from low facial [angle] = Very fond of cactus run away like dogs from one another with pieces — Excavate Burrow shallow — first on one side & then on other — two or three time throw dirt with one arm & kick it out with well adapted hind leg then on other side (pp. 48b-50b).

The very last entry actually written on James is the single word 'Comet', p. 50b. The David Stanbury archive at Christ's College, Cambridge, seems to show that Stanbury was the first to have realised that this entry refers to Halley's Comet, which was at its minimum distance from Earth on 13 October 1835. Darwin should have been able to see the comet with the naked eye soon after sunset on any clear evening at about that time. In fact he probably had a telescope with him so would have had an exceptionally good view of the comet.Chancellor's Beagle at the Galapagos

The Beagle having returned from her nine day circuit via Chatham, Hood [Española] and Charles to collect water, tortoises, wood, potatoes, pigs and mail, sent in boats at 2.30pm on the 17th to retrieve Darwin's party: 'Ship came' (p. 50b). He was back on board by 5.00pm and recorded that on the 18th they 'Ran along Albermarle Isd' and there was one last geology note: 'One of the mounds in Albermarle most covered with bare Lava — Mounds 4000ft high' (p. 51b). This was probably Volcán Darwin. The final notes from the Galápagos are calculations on the speed of tortoises, in ink: '30 yard in 5 minutes 360 — in 1 hour' multiplied by 24 hours gives four and one-third miles per day.


On 19 October the Beagle sailed north to pick up Mr Chaffers in the yawl at Abingdon [Pinta]. On the 20th FitzRoy set a course west-south-west and the Beagle commenced her month-long 5,000 km passage across the Pacific to Tahiti.

Tahiti, November 1835

The last four front pages following the Galápagos field notes seem to date from the passage across the Pacific in late October or early November. This dating is not secure but is based on consideration of the topics discussed which seem to relate to South America and the Pacific.

Darwin noted that William Ellis in his Polynesian researches (Ellis 1829) 'states that the Austral Isds have only lately been inhabited are they low Isds? Corall rapidly growing in the Low Isds?', p. 30a. Darwin here seems to be reading up in advance of reaching the Low or Dangerous Archipelago [Tuamotus] which the Beagle sailed through starting on 9 November, giving him his first close views of coral atolls. Admiral Krusenstern's chart of the Low Archipelago and the Society Islands, including 'Otaheite or Tahiti', showing the Beagle's track through the islands, is included in the appendix to Narrative 2.

The following two pages refer to four other books, all in the Beagle library. See Correspondence, vol. 1, Appendix VI. On p. 31a Darwin's thoughts seem to have returned to boulders 'being carried on plains of Patagonia by any violent motion excepting by one beneath the sea'. He then wondered in response to reading Daubeny's 1826 book on volcanoes 'Is not Olivine present?' perhaps in one of his Galápagos trachyte specimens. Ellis is mentioned again on p. 32a in connection with Hawaii, then Darwin noted 'Strong Earth quake useful to Geologist, can believe an amount of violence has taken place on earth's surface & crust'.

On the next page Darwin jumped with no obvious connection from 'Mad dogs. Copiapo' to 'S. Cruz — Glaciers', then observed 'On the Atlantic side [of South America?] my proof of recent rise become more abundant at the very point where on the other [Pacific?] side they fall'. This passage is unclear although if 'proof' and 'fall' are opposites then Darwin is testing the effectiveness of his argument for continental uplift. The Santa Cruz entry may mean that the passage refers specifically to the fact of Andean glaciers mainly flowing towards the Pacific. Finally, on p. 34a he noted to himself 'Collect all the data concerning recent rise of Continent' and the Tahitian river name 'Tia-auru [Tuauru] Piho'.

Switching now to the back pages, a note on p. 52b 'Fresh water fish' surely indicates that Darwin had started to explore Tahiti on foot. This entry must date from just before the first date 18 November further down the page, in which case it was the day when Darwin saw the beautiful view of Eimeo [Moorea] Island in the distance. As Armstrong 2004, p. 139 explains in his excellent account of Darwin's stay on the island, Tahitian dates were a day ahead of those the Beagle brought with her at the start of her ten day stay. The references to Bynoe's information on 'direction of slate in Obstruction Sound' in southern Chile and 'angular fragment of Granite on Icebergs' seem oddly out of place written in such a tropical paradise as Tahiti. Bynoe is mentioned in connection with Obstruction Sound in the Red Notebook, p. 141e.

18 November commences with 'travelled up valley'; this is the Tia-auru valley on the northwest side of Tahiti which was mentioned on p. 34a. The Tahitian entries are generally intensely atmospheric:

at first beautiful view over cocoa nut trees — 2 fine men, take no cloths or food — Higher up valley very profound — most dangerous pass — ropes — Kotzebue — The one with pole, ropes, dogs & luggage. — Wonderful view — Cordillera nothing at all like it. (pp. 52b-53b).

Darwin's small party 'Ascended a Lava slope' which was 'excessively steep', pp. 53b-54b. With a 'vertical sun' it was 'Steaming hot' with waterfalls and 'enormous precipices' all around. The vegetation was lush with 'Bananas & trees', no doubt reminding Darwin of Brazil. After climbing the 'fern hill' he threw himself into the shade of 'thick trees surrounded by sugar', pp. 54b-55b. There were plants to eat everywhere: 'Yams, Taro — Sweet root like sugar' and the rivers were full of 'fish & Prawn'. His two companions caught these creatures 'diving gracefully amphibious', p. 55b. It appears that the 'Darwin' prawns belonging to the genus Macrobrachium which are today preserved at the Oxford University Museum were among those caught that day. See Chancellor et al. 1988, p. 222. The cliff of columnar lava on the Tuara river where Darwin ate his lunch is beautifully photographed in Catlin 2009, fig. 5.

On the next page Darwin thought 'only famine & murders' could have induced people to explore the 'really most fearful road'. He noted that his companions had learnt 'a little English' and that their way of making fire by rubbing a 'Carpenters tool' reminded him of the gauchos, p. 56b. The valleys were like 'mere crevices'. The rocks were 'grey base, with nests of olivine', together with conglomerates, clays and sandstones, pp. 57b-58b. In Volcanic islands, echoing the notebook, Darwin recorded that he 'picked up some specimens, with much glassy feldspar, approaching in character to trachyte', p. 26.

The men who were guiding Darwin told him 'not to tell Missionary' about their eating 'deadly ava', an 'acrid, poisonous stimulative taster', p. 60b, but they would 'not drink — Spirits', p. 58b. They bivouaced at a 'cool stream where we bathed buried in peaks', Their shelter was thatched with banana leaves which ensured a 'dry bed' even though that night there was 'much rain', pp. 58b-60b. They enjoyed a 'supper baked in stones' of 'fine vegetables' and could hear 'another cataract of 200 ft'. The men said their 'prayers & grace [with] no compulsion'. Darwin declared the evening all in all 'sublime', p. 59b.

On 19 November Darwin 'returned by other road' so 'avoiding cascades', p. 61b. They were walking along a 'knifes edge' using ropes in one place. He noted that the men were 'very strong' and tattooed with 'flowers round head'. They 'caught some fine Eel', presumably by hand as Darwin noted this as 'Evidence how man can live by hand', p. 62b. He was deeply impressed by the steepness of the ravines and the ridges separating them which were 'about same angle as a ladder'. Somehow the 'vegetation clings on…up to the highest peak', that is over 2,000m. By breakfast he had an 'enormous appetite', p. 63b and ate a 'mass of Banana!!', but it was 'fatiguing travelling so far poising each step with greatest care', p. 64b.

That night they 'slept under [a] ledge of rock' and watched the stars. The next day, Friday, they returned and met a 'party of noble athletic figures travelling for Tayo'. Darwin found the Beagle had moved to Papawa so 'walked round' to meet her. On the 21st the 'Ship returned' to Point Venus, where Captain Cook had observed the transit of Venus in 1769. On Sunday 22 November Darwin 'went down to Papiete in boat' to hear the 'Tahitian service'. He thought the congregation did not pay 'much attention' but that they looked 'respectable'. There was 'good singing' although the sound was 'not Euphonious'. Darwin judged the missionaries to be 'good' and that one could never 'believe what is heard', p. 65b. This favourable view of the missionaries fed into Darwin's first Beagle publication, his joint letter to the South African Christian Recorder (FitzRoy and Darwin 1836).

The single word 'reef' for his canoe trip on 23 November must be the shortest notebook entry of all, and gives no indication that probably within a week or so Darwin would be drafting his 'Coral Islands' manuscript (see introduction to the Santiago Notebook). On the 25th Darwin recorded having breakfast with the missionary Charles Wilson at Papiete and attending Queen Pomare's party. Finally on the 26th he noted the 'great Parliament' called by the Queen to decide how to respond to FitzRoy's 'request' for settlement of an unpaid compensation fee to the British Government. So far as is known this is the last notebook entry Darwin made in 1835.

The Beagle headed out of Matavai Bay on the evening of 26 November and resumed her east-south-east bearing for New Zealand. Darwin stowed his fish and other Tahitian specimens safely away for the month-long voyage, started to write up his diaries, putting the Galapagos Notebook aside with the others. He seems to have looked over the Galapagos Notebook when writing his Journal of researches and the Geology of the Beagle after which, as far as is now known, he never used it again. Certainly Darwin would never for a moment have believed that at some time in the distant future thousands of people from all around the world would be examining his jottings in the notebook he carried in his pocket on the Galapagos for a few short weeks in 1835.

Gordon Chancellor and John van Wyhe

September 2008

See also an introduction to the Galapagos pages by Chancellor and Keynes here.

'Galapagos. Otaheite Lima' (1835). Text Image Text & Image EH1.17 [English Heritage 88202337]

1 The Galapagos Notebook has c. 3,600 words. Only the Sydney Notebook is shorter, at c. 3,100.

2 The last known recorded sighting of the notebook was in 1976 and it seems to have been missing from Down House by 1982.

3 In Variation (p. 9) Darwin seems to imply that he perceived the 'American-ness' of the Galápagos cactus flora.

4 In his Beagle writings Darwin used the name Otaheite less often than Tahiti, which is the name he used in his Beagle diary, his zoological diary (DAR31.345) and his geological diary (DAR37.798-801). He sometimes used 'Tahiti (Otaheite)', as for example in Volcanic islands.

5 Darwin wrote to Fox on 7-11 March, Henslow on 10-13 March and 18 April and to his sisters Caroline on 10-13 March and Susan on 23 April. Perhaps the last two are the 'Women' mentioned on p. 4b? See Correspondence, vol. 1.

6 Nicholas Lawson's claim is somewhat exaggerated but it is the case that the subspecies of tortoise vary in the shapes of their carapaces. 'Saddlebacks' are from islands where the tortoises have to stretch up their necks to obtain food. 'Domebacks' are from islands where there is plenty of low level vegetation.



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