Darwin and Macleay

Introduction

Had Charles Darwin been a Galapágos tortoise he would have celebrated his 200^th birthday ten days ago. If this notion seems a little Alice-in-Wonderland-ish, it sets the tone for this afternoon. For I want to take you on an imaginative journey, to try to unknow what you know in order to gain a new understanding. The idea of evolution is now deeply implicit in our perception of the natural world. Evolution by natural selection is undoubtedly one of the really big ideas in the history of human thought. No one has done more than Darwin to shape our understanding of the processes of nature and our place in it. Yet the idea was hard-won, both intellectually and socially. To appreciate it one has to imagine the mental world before Darwin – hence the need for unknowing.

But first, let me remind you of what you must unknow! Darwin did not invent the idea of evolution. The idea of the world changing, and living forms with it, is an ancient one. But the philosophical idea of nature evolving gained a more active currency at the beginning of the nineteenth century. Darwin’s grandpapa Erasmus presented a sweeping view of the evolution of life in his long poem The Temple of Nature, published posthumously in 1803. More influential in scientific thought at the time was the work of the French naturalist Jean-Baptiste de Lamarck, who published his idea of the working of evolution in Philosophie Zoologique in 1809, the year of Darwin’s birth. The famous metaphor is that of giraffes stretching their necks to reach food, the more successful ones being those which could stretch further, secure more food, and pass their advantage to their offspring. The phrase associated with Lamarck is ‘the inheritance of acquired characters’. While this is a vast oversimplification and to some extent distortion of Lamarck’s complex views, it is sufficient for us to recognise that Lamarck was a highly skilled and widely regarded taxonomist (classifying specimens), that he espoused a transformist view of nature, and that he offered a mechanism by which that transformation could occur.

There was another book, published in the 1840s, which (in the words of James Secord) ‘brought an evolutionary vision of the universe into the heart of everyday life’, but we will come to that book a little later on.

Many factors came together to shape Darwin’s idea, but undoubtedly his diverse experiences of nature during the course of the voyage of HMS Beagle were a key element. Darwin was a keen collector of beetles while studying at Cambridge, but it was geology that was his first serious scientific focus. And his observations of geology in South America, filtered through the prism of Charles Lyell’s just-published Principles of Geology, with its emphasis on geological processes working slowly over very long periods of time, shaped his perception of the diversity of plants and animals he observed along the way.

Contrary to popular thought, Darwin did not carefully observe the differences between the finches on the various islands of Galapágos at the time. This only emerged later. But the years immediately following the Beagle voyage were ones of rapid intellectual advance for Darwin. Writing his account of the voyage, his Journal of Researches, as a companion to FitzRoy’s Narrative, provided the opportunity to think over his many experiences in relation to each other. His concept of natural selection as the mechanism of evolution was fully developed by 1839, within three years of his return to England. The implications were enormous, and Darwin sat on evolution for the next 20 years, finally goaded into print by a letter sent by Alfred Russel Wallace from the East Indies outlining the same fundamental idea. Darwin could keep the idea to himself and a few scientific friends no longer. So this year is also the 150th anniversary of the publication of Darwin’s short book On the Origin of Species by Means of Natural Selection.

He had not been idle in the mean time, spending several years doing detailed taxonomic work on those puzzling marine creatures, barnacles, both current and fossil. How could one prove one’s credentials as a naturalist without such taxonomic labour? But for Darwin this labour was filtered through a constant lens of evolutionary relationships. An idea was one thing, but an unassailable body of evidence was needed to defend himself from the critics. And the mid nineteenth century was a period when scientific issues were much more public property among the educated than they are today.

Darwin and Wallace both developed their ideas from a combination of reading current scientific and social literature and a detailed experience of natural history in varied climates, importantly including the tropical. This afternoon we are in the house built by Alexander McLeay and occupied by his son, William Sharp Macleay, for the last 25 years of his life. W.S. Macleay gained a considerable reputation in Britain as a naturalist in the 1820s. So one might ask the question, Why was it that William Sharp Macleay did not also develop the idea of evolution by natural selection?

I will begin by outlining Macleay’s life, then look at the setting of ideas about natural history in the early decades of the nineteenth century, and finally draw some comparisons between Macleay’s experiences and those of Darwin and Wallace to try to get an understanding of the elements which fed into the development of the concept of evolution by means of natural selection.

William Sharp Macleay

William Sharp Macleay was renowned as a philosophical naturalist. He grew up in an environment steeped in the natural history of his day. Born in 1792, he was the first child in a prolific family and was named after his father’s business partner in the wine trade in London. His father, Alexander McLeay, had left the cold north of Scotland for the opportunities of London, then the leading metropolis in the world. When William was still an infant, Alexander joined a society devoted to natural history – especially botany – the Linnean Society of London, founded by James Edward Smith in 1788. This was an era when gentlemen maintained ‘cabinets’ – collections of specimens, curiosities, models or instruments stored in handsome pieces of furniture.

Alexander collected in a number of areas, but insects became his particular proclivity. His commitment to natural history and the Linnean Society led to his appointment as honorary secretary in 1798. This close connection to the networks of natural science brought him in contact with the President of the Royal Society, Sir Joseph Banks, who had the ear of government on scientific matters. It was probably through the patronage of Banks that Alexander McLeay moved from being a wine merchant to a civil servant. There was an expansion of government bureaucracy to sustain the war with Napoleonic France. McLeay rose to become secretary of the Transport Board, the department concerned with government-related shipping, not just for war purposes but also for such matters as the shipment of convicts to penal colonies like New South Wales.

So during his teenage years William was exposed to the richness of natural history expressed through Papa’s burgeoning collection of insects, many of them captured in that highly developed hunting ground, the auction room. He also became acquainted with his father’s scientific friends, men like the Rev. William Kirby, co-author with William Spence of Introduction to Entomology, published in four volumes between 1815 and 1826. Macleay’s education at Westminster School in London gave him a sound knowledge of Latin and Greek, languages so much associated with the scientific naming of plants and animals. Trinity College Cambridge followed, Macleay graduating BA in 1814.

As a bright and precocious young man, much was to be expected of William. No doubt through his father’s civil service connections – this was an era of patronage – Macleay was appointed attaché to the British embassy in Paris in 1814 after the defeat of Napoleon. Macleay’s stay was cut short by Napoleon’s escape from Elba and the dramatic events culminating in the Battle of Waterloo and Napoleon’s final exile to a windswept island in the South Atlantic. After this, Macleay was appointed secretary to the board for liquidating British claims on the French government. While this was based in London, it provided opportunities for Macleay to spend time in Paris.

Paris was a centre of intellectual ferment throughout the Revolutionary and Napoleonic years. We have already encountered Lamarck. While Lavoisier had lost his head in the worst of the Terror, there were many other scientists who weathered the upheavals of changing allegiances. Georges Cuvier more or less created the science of comparative anatomy, in which the skeletons of living and fossil animals could be compared. He showed that fossil elephants differed from living ones and thus that extinction had occurred. He espoused a view of catastrophism in which whole groupings of animals died in cataclysms and were replaced by new groupings of animals. There were numerous other natural scientists in Paris and the debates between them were vigorous.

It was in this period that Macleay developed his classificatory scheme for defining the relations between different species, and between different groupings higher than species level. This described circular groupings of five elements and hence came to be known as the circular or quinary system.

In considering the terminology used to describe nature in a pre-Darwinian setting one has to be careful not to assume the meanings of words like ‘relation’, ‘family’ and ‘affinity’. These do not imply a relationship of descent from a common ancestor but merely a classificatory grouping, the working out of a set of patterns ultimately by the hand of God. They are philosophical terms rather than biological descriptions. It was in this context that Macleay drew a distinction between ‘affinity’ and ‘analogy’, the difference between similarities within a grouping and similarities between species belonging to different groups. This foreshadowed what we would think of today as actual biological relations on the one hand and examples of convergent evolution, animals of different groupings developing similarities by performing similar functions, on the other. The quinary was a highly formalised system in which affinities defined the elements within circles and analogies for matching elements of adjacent circles.

Macleay described his system in his book Horć Entomologicć. Two parts were published in 1819 and 1821, comprising volume 1. The book was ill-fated. Fire destroyed much of the print-run of part 1 and flood damaged part 2. No second volume was ever issued. Nevertheless, Macleay’s quinarian ideas gained currency among zoologists in London, notably William Swainson and Nicholas Vigors. Macleay’s ideas were much debated in the Zoological Club of the Linnean Society in the 1820s. It was the prolific author Swainson more than anyone who gave the quinary system wider public recognition.

Meanwhile in the general retrenchment following Waterloo, the Transport Board was disbanded and Alexander retired on a pension, too much of which passed through the account books of the auction houses. When the NSW governor, Sir Thomas Brisbane, was recalled, McLeay’s government friends secured for him appointment as Colonial Secretary, working with the new governor, Ralph Darling. His scientific friends hoped for a growing stream of specimens from the topsy-turvy continent, which ‘bursts upon our view at the first glance like a new creation’, as Edward Donovan had expressed it twenty years before. Instead McLeay found himself working longer hours than ever he had in London. Such leisure as he had he devoted to the development of his land grants – here at Elizabeth Bay and several pastoral properties.

William had demonstrated his proficiency as a government official in London and Paris. The prospect of an appointment in New South Wales was sounded, but the government had other ideas. In the wake of the Napoleonic Wars, in which Britain had played the principal role in driving French forces out of the Iberian Peninsula, Spain was effectively driven to accept a treaty intended to end the trans-Atlantic slave trade. You will recall the events of a couple of years ago marking the 200^th anniversary of the abolition of the British slave trade. Slavery itself was not ended in British colonies until 1833. For the Spanish, with many of the former American colonies now independent, the large island of Cuba was the principal destination for slaves. Slaves toiled under a tropical sun to produce sugar, coffee and tobacco. The severity of the conditions produced a high rate of attrition. The work could only be kept up by a constant supply of new and young slaves from Africa.

In 1825 William Macleay was appointed the junior British member on the mixed British and Spanish court of commission for the abolition of the slave trade. A ‘very circuitous and tedious passage’ saw Macleay arrive in Havana at the end of 1825. The task he undertook for the next ten years was an unenviable one. Havana was quite a cosmopolitan place with increasing connections with American business interests as well as its traditional colonial ties with Spain.

Macleay took a house on high ground across the harbour at Guanabacoa. This probably provided refreshing sea breezes to counteract the soporific effects of the tropical heat. Towards the end of his stay Macleay sketched his house. The caption on the sketch reads: ‘Guanabacoa with a view of my house in the distance. The last house I lived in. The view is taken from the upper window of my first house.’

Slavery itself continued on Cuba. The role of the mixed court was to deal with the slave-bearing ships that were apprehended before they reached Cuba and discharged their cargos. A voluminous correspondence testifies to the successes and failures of the task.

Here is a letter from six months after Macleay’s arrival:

Havana 30th June 1826

Sir, We have the honor to enclose copies of the Register of the Slaves emancipated by Decrees of the Mixed Commission since the date of /Mr Kilbee’s/ Despatch No. 43 /of the 17^th December/ 1825.- They belonged to the Spanish vessels Magico, Fingal and Orestes, and amount in all to 445. [signed by Henry Kilbee and W.S. MacLeay]

I don’t wish to dwell on the details overly, but it is worth a brief glimpse of what this means in human terms. The Fingal landed 58 slaves. Of course, it was not uncommon for slaves to die in the course of a voyage. The tabulation is very vivid in recording not only the African and ‘Christian’ names of the slaves, but their sex, age, height and the African nation to which they belonged. There were several boys only 10, 11, 12 years old. Among the 175 slaves emancipated from the Magico were three nine-year-old girls. 212 were released from the Orestes.

These were successes but there was a constant cat-and-mouse game with ships unloading their cargos at other parts of Cuba and arriving in Havana empty or cases where ships slipped into Havana and unloaded at night with all sorts of dignified uncooperation from the Havana authorities.

It must have been a very difficult social setting for the patrician Macleay, the Havana residents and neighbouring landholders of his own social standing being government officials and plantation owners more or less closely involved in the use of slave labour. It was in this setting that Macleay developed a romantic attachment with Emelia Drake. The little we know about the affair comes from Macleay’s sister Fanny’s letters in response to his own which were lost, or more likely suppressed after Fanny’s death. Emelia was young (compared to the 35-year old Macleay) and Catholic, the daughter of James Drake, the founder of a large Havana business house and Macleay’s landlord. For whatever reason – age difference, religious difference, Drake’s objection – marriage did not ensue. One can understand that Macleay took solace in his garden and his pet crocodile.

In 1830 Macleay was appointed to the senior British position on the court of commission, finally leaving Cuba in 1836 and returning to England. He visited naturalists in the United States on the way. He rapidly resumed prominence among British naturalists, joining the councils of several scientific societies, donating Cuban specimens to the British Museum, and meeting up-and-coming naturalists such as Charles Darwin, not long home from the Beagle voyage.

Macleay was prominent in encouraging Darwin to publish a Zoology of the voyage. Early in 1838 Darwin made a careful study of Horae Entomologicć in Cambridge University Library. The first time Darwin dined at the Athenaeum, later in the year, Macleay was one of the party. While they were both in London, their paths crossed a number of times. When Macleay came to Sydney Darwin did not forget him. Darwin's servant Syms Covington migrated to Australia in 1839 bearing a letter of introduction to Macleay.

Whether from the long separation from his parents and sisters, or his habituation to a warmer climate, or the sense that the scientific scene in London had moved on too far in his absence, is hard to say. At all events, in 1838 Macleay gathered up long-stored possessions and accompanied his two orphaned cousins to Sydney.

Macleay spent the last 25 years of his life in Sydney, an increasingly isolated figure. His beloved sister Fanny had died before he arrived. In the face of the severe economic depression of the early 1840s, Macleay took possession of this house [Elizabeth Bay House] from his father, for whom it had been built, in discharge of the enormous debt to his son Alexander had accrued. Perhaps one can draw a comparison between the palatial residence at Guanabacoa and this imposing house on high ground above the harbour. But without a crocodile, Macleay had to resort to notices warning would-be trespassers to ‘beware of bloodhounds’.

Nevertheless, Macleay was able to maintain the position of savant in Sydney. He fostered the institutional development of science and education in the colony, and provided unique support for visiting naturalists, notably Joseph Hooker and Thomas Henry Huxley, both assistant surgeons on Royal Navy ships which visited Sydney in the 1840s.

As Macleay was sorting out the family finances in Sydney in 1844, a book was published anonymously in London which brought Macleay’s name and his system of classification to wide notice – and in a most controversial context. Vestiges of the Natural History of Creation was launched on an unsuspecting public in October 1844. Drawing on new scientific discoveries in geology, embryology and other disciplines, the unknown author set out his theory of life, the universe and everything. It was a universal theory aimed at a conclusive demonstration of the ‘development hypothesis’ – that animate nature as well as inanimate was transformed through time and by natural processes according to universal law. The author devoted a whole chapter to the ‘Macleay System of Animated Nature’. This was ironic as Macleay’s circles were a reaction against Lamarck’s transmutationist ideas. The circle was formed when Macleay brought together the ends of two branching series of organisms as represented by Lamarck.

Vestiges was met by a flood of critical reviews, the excitement spurred on no doubt by its very anonymity. The public responded by buying the shocking volume in huge numbers, enabling a rapid succession of editions to appear. While the author was writing Vestiges in the early 1840s, the Quinary system still had considerable currency among some British naturalists. By 1844 it had almost completely lost support and was a point of criticism that the author of Vestiges – the Edinburgh writer and publisher Robert Chambers as it was revealed only much later – responded to. Quinarianism was markedly on the retreat by the third edition (February 1845) and disappeared completely in the fifth edition (January 1846).

The publication of Vestiges can only have made it more difficult for Macleay to discuss quinary classification with such few naturalists as came his way who would have been interested in these matters. And presumably for Macleay, classification remained quinary and circular. Even some years earlier Joseph Hooker had found that Macleay ‘seemed rather cautious about broaching his Quinary system’. Hooker had been ‘rather anxious to hear how he thought it would apply to the higher order of plants’. The quinary system never had the following among botanists it had with zoologists. Although initially attracted to the system, Hooker ‘fairly worked myself out of that error by the mosses, which I first arranged to please McLeay himself’.

Macleay’s system came under concerted attack at the British Association meeting in 1843. H.E. Strickland discussed his ‘Chart of the Natural Affinities of the Incessorial Order of Birds’. The reporter for the Athenćum paraphrased Strickland’s conclusion ‘that the true affinities of organic structures branch out irregularly in all directions, and that no symmetrical arrangement or numerical uniformity is discoverable in the system of nature when studied independently of preconceived theory’. Macleay was not explicitly mentioned (at least in the report) but the implication was clear. The discussion was a chorus of criticism. Richard Owen ‘rejected altogether quinary, circular, and other systems’.

Before Natural Selection

So, to return to our imaginative journey, suppose the letter from Professor Henslow in Cambridge, conveying the offer of the position of naturalist on HMS Beagle, had never reached Darwin’s father’s house at Shrewsbury in August 1831, or that Dr Darwin had stuck to his guns (good hunting guns, no doubt) and insisted that his would-be doctor, cum would-be clergyman son not embark on something he regarded as a ‘useless undertaking’. Suppose that we had never heard of the Rev. Charles Darwin, who lived a quiet life as the rector of a rural parish, going on country rambles, still collecting beetles as he had at Cambridge, and contributing no more to natural history than the keeping of a diary in the manner of the Rev. Gilbert White of Selbourne, or writing useful but innocuous books like the Rev. William Kirby.

What was the mental cast of the world which Darwin shifted for ever? The English, declared the Swiss chemist C.F. Schönbein about the time of Darwin’s birth, ‘have a peculiar love of regarding Nature from a theological point of view.’ For many centuries the Bible had provided a framework for understanding the development of the physical world. This had been only partially modified by the scientific advances of the seventeenth and eighteenth centuries. Indeed, the Book of Nature came to hold a place complementary to the Bible as evidence of the handiwork of God. William Paley’s Natural Theology, published in 1802, was a prominent expression of this.

The rapid development of science in the early decades of the nineteenth century elicited a range of religious responses in England. Geology was prominent in this. A Geological Society was founded in London in 1807. The rapid advance of geological ideas presented a challenge to biblical literalists. The 1820s and 1830s were fundamental to many of the key ideas in geology. Strata were defined on the basis of the fossils embedded in them, notably the Cambrian, Devonian and Silurian systems of the Palaeozoic. The early 1830s also saw the publication of the three volumes of Charles Lyell’s Principles of Geology. Archbishop Ussher’s determination, in the mid seventeenth century, of the world’s formation in 4004 BC, based on deep biblical and historical scholarship, left a powerful legacy for understanding the physical processes of the world. Although others before him, notably the Scottish geologist William Hutton at the end of the eighteenth century, had argued for geological processes occurring over almost limitless time, it was Lyell who gave wide currency to the idea of familiar processes acting gradually over very long periods of time to shape the face of the earth as we now know it. It was this ‘time-bomb’ which Darwin carried on the Beagle.

The biblical literalists responded to the new geology with numerous volumes of Mosaic geology. Vociferous though they were, they could not deal a winning hand. Moderates found an accommodation between science and religion. This was best expressed in the series of Bridgewater treatises published in the 1830s. The eighth Earl of Bridgewater had bequeathed funds for eight scientific authors to prepare works demonstrating ‘the Power, Wisdom, and Goodness of God, as manifested in Creation’. The new scientific learning gave scope for detailed elaborations of Paley’s principle that the perfect relation of design to function revealed the benevolent hand of God. Four of the authors were clergymen and all were closely acquainted with science.

This was the setting in which Macleay could find a comfortable place, neither taking the Bible as a scientific guide, not rejecting the hand of God in the workings of the world. As Macleay wrote to the clergyman-geologist W.B. Clarke in 1842: ‘I cannot consider the Bible as a Scientific Book according to the vulgar meaning of the word “Scientific”; and although I do not conceive that Moses wrote any thing inconsistent with the truth, I confess I have as much confidence in his opinion on the binomial theorem as I have in his dictum on Geology’. No wonder Bishop Broughton thought of Macleay and others as ‘irreligious men, ... not friends of the Church’.

So, while religious liberals were accommodating to the systematising advances and conceptual innovations of scientific ideas – many of the innovators themselves ordained Anglican clergymen – the world of the educated elite was only partly prepared for an evolutionary view of nature. Had Darwin not sailed on the Beagle, and had Alfred Russel Wallace, like his brother Herbert, succumbed to yellow fever, it might have been some decades more before the controversy broke, or perhaps by then there would have been a much lesser controversy.

So now we can ask, Why did WSM not discover evolution by natural selection? To approach an answer to this it is worth examining various parallels and contrasts in the lives of Macleay, Darwin and Wallace.

Insects

If we were to analyse all the wildlife documentaries made since David Attenborough’s Life on Earth series 30 or so years ago, I think we would find that the most amount of air-time was given to mammals, particularly big cats, elephants, whales and apes. Birds, reptiles and fish would also get a good look in. Insects would come a long way down the list – small and easy to ignore, except when they irritate us. In fact, insects get far more air-play in advertisements – for eradicating flies, mosquitos, cockroaches &c. So it might come as a surprise to find that insects, indeed beetles, are a very distinct common element between Macleay, Darwin and Wallace. They all had a very strong interest in beetles in early adulthood.

The focus of Macleay’s Horae Entomologicć of 1819 was the scarab beetle. Darwin developed a passion for collecting beetles in Cambridge. And what set Wallace on his path as a naturalist was the chance meeting with 19-year-old Henry Walter Bates, who had already published a paper on beetles. They were soon off to the Amazon to collect beetles.

While large animals, like whales and elephants are impressive, they are relatively rare (and specimens of them hard to store in any numbers). Insects, however, are numerous and diverse, and the largest grouping of insects is beetles. Among beetles, weevils comprise the grouping with the largest number of species. It is possible to have hundreds of specimens of an individual species of beetle, rather more difficult with birds or mammals (though many naturalists did their best to denude the forests and jungles). With numerous specimens, the taxonomist is confronted with a huge gradation of anatomical details – between genera, between species, and within species. A keen interest in beetles therefore can be seen as a very significant if not crucial foundation for the development of evolutionary ideas. There is surely a major cultural history to be written about the enthusiasm for beetles in the late eighteenth and early nineteenth centuries.

We might also consider that two features of biogeography provided experiences in common between Macleay, Darwin and Wallace. The first is familiarity with tropical as well as temperate climates. I will come back to this point. A related but different point is the importance of island ecologies. While Macleay had spent a decade on the fertile island of Cuba, Darwin and Wallace had both seen much of animals and plants on clusters of smaller islands. The Galapágos is the obvious example, but Darwin had been alert to islands since the Beagle’s first landfall in the Cape Verde Islands.

Wallace likewise had journeyed extensively among the islands of the Malay Archipelago, discovering the biogeographic divide between Bali and Lombok which came to be known as the Wallace line. Macleay probably had little opportunity to explore the uncultivated parts of Cuba. (Indeed, one can speculate that there were those who would gladly have aided in his ‘accidental’ death had he ventured to remoter regions!)

Early career programs

Darwin reflected in his autobiography that the ‘voyage of the Beagle has been by far the most important event in my life and has determined my whole career’. It was not simply the opportunity to ‘attend closely to several branches of natural history’, but the habits of work and mind that ship-board life instilled in him. Similarly, Wallace regarded his Malayan years as ‘the central and controlling incident’ of his life.

We might regard these episodes in modern terms as Darwin’s and Wallace’s ‘early career’ programs. Darwin was not quite 23 when he embarked on the Beagle. Wallace was 25 when he sailed for the Amazon and still only 31 when he reached Malaya. What was the equivalent for Macleay? His years in Paris in the mid to late 1810s. This was when he was exposed to the ferment of ideas among French naturalists, but it was nature at second hand. He had already tied himself to a static view of nature in the quinary system by the time he reached Cuba. And the demands of official responsibilities prevented the opportunity for the kind of deep engagement with living nature that characterised both Darwin’s and Wallace’s experiences.

Ideas

Ideas don’t come from nowhere. Books were important as well as beetles. Apart from Lyell’s Principles, Darwin and Wallace were both keenly influence by the ideas about population and reproduction in Thomas Malthus’s Essay on Population, published in 1798. Very many other books also played a role in the development of both Darwin’s and Wallace’s understanding. Macleay was regarded as ‘a man of immense general information’ with a remarkable memory, ‘equally versed in zoology and botany’. That he was also somewhat acquainted with current geology is indicated by his correspondence with W.B. Clarke. Nevertheless, there is no indication that he was influenced by social literature, such as Malthus’s Essay, in his approach to the workings of nature.

Geology

One may take the aspect of geology a little further. It should be clear by now that geology should not be seen as an adjunct interest for a natural historian primarily concerned with botany or zoology. Rather, through Lyell’s spectacles, it was the foundation for Darwin’s and Wallace’s understanding the context within which living species existed, competed and were transformed over time. Darwin’s reading of Charles Lyell’s just published Principles of Geology shaped his experience of landforms throughout the Beagle voyage, affecting his interpretation of the plants and animals he saw along the way. Lyell’s Principles was also a shaping influence on the young Wallace’s developing scientific interests in the 1840s (along with Malthus’s Essay on Population and Darwin’s Journal of Researches from the Beagle voyage).

Correspondence networks

The social setting in which intellectual work is undertaken must also be considered. Despite popular books on lone geniuses changing the world forever, science is in many respects a social activity. There is a fruitful tension between the single-minded pursuit of a line of investigation by an individual and the forms of support, critique and validation provided by collective processes. Societies, journals and correspondence networks all played an important part in scientific endeavour in the nineteenth century – rather more so than today when there is much more scope for institutionally based science in universities, research organisations and corporate R & D laboratories.

Macleay was particularly active in societies in the years immediately before and after his Cuban sojourn. His standing was such that he presided over the zoological section of the British Association for the Advancement of Science meeting in Liverpool in 1837. After the early post-Beagle years, Darwin moved to Downe in Kent. This limited his capacity to engage in the meetings of scientific societies in London, but he assiduously developed a very large network of correspondents. Through this he could solicit a great variety of information that he brought to bear on his researches. His friends also kept him informed of metropolitan activities, so the absence from meetings was not a large disadvantage. Wallace was drawn into Darwin’s correspondence network through the solicitation for specimens.

While the comparisons could be drawn at considerable length, the key point is that societies, meetings and correspondence networks served to advance an individual’s scientific ideas once they had been formed. Darwin was effective in subordinating these social aspects of science to the underpinning of his ideas, and later his advocates, especially Huxley and Hooker, used them to promote evolution, but they were secondary to the generation of ideas compared with literary sources and field experience. And Macleay, in his years of retirement in Sydney, when he was expected to turn his notes and manuscripts to good use, failed to maintain correspondence networks that might have compensated for his remoteness from centres of scientific advance.

Lord, What is Man?

One of the big obstacles to the acceptance of evolution in the nineteenth century (and since) was the implication it had for human evolution and the removal of the active agency of God. We will consider this briefly in a moment but for now it is worth comparing our subjects’ encounters with human diversity. In Cuba, Macleay encountered Creole and slave populations as well as Europeans, but not coherent indigenous societies unaffected by prior European contact. Here Darwin’s and Wallace’s experiences are in sharp contrast: Darwin with the inhabitants of Tierra del Fuego and Wallace with the native peoples of the Rio Negro and the Malay Archipelago.

While Darwin omitted overt reference to the evolution of man in the first edition of Origin of Species, the implication was clear. By the time Darwin published The Descent of Man in 1871, Huxley’s Evidences as to Man’s Place in Nature and Lyell’s Antiquity of Man had both appeared, as had Wallace’s paper ‘The origin of human races and the antiquity of man deduced from the theory of “natural selection”’. Man could no longer be considered as separate from the processes of nature.

Before concluding we need to look briefly at the responses of Darwin to Macleay’s ideas and vice versa.

Darwin’s reaction to the quinary system

The first publication of Darwin’s and Wallace’s ideas about evolution by natural selection came at a time neither had chosen. Wallace had embarked upon his tropical adventures already imbued with the evolutionary ideas of Vestiges of the Natural History of Creation. He had gone looking for a mechanism. Wallace, in the East Indies, was already in correspondence with Darwin when in 1858 he sent him an essay ‘On the tendency of varieties to depart indefinitely from the original type’. This set the cat among the pigeon fanciers! Here was the same fundamental idea Darwin had been sitting on for 20 years. What was to be done?

Darwin had only shared his ideas with his closest scientific friends, but clearly the issue of priority was now at stake. Wallace’s paper was read at the next meeting of the Linnean Society of London in July 1858 along with extracts from Darwin’s unpublished writings. Wallace’s paper was subsequently published without his formal permission. He was merely seeking Darwin’s advice. Given the choice he may have intended to elaborate his ideas considerably before going into print.

Darwin on the other hand had had the luxury of the painstaking accumulation of evidence in support of his ideas. He knew the implications of evolution by natural selection challenged many of the most deeply held beliefs of his society, and he needed as solid a case for the reality of evolution by natural selection as he could construct. But what in particular held him back so long?

When the Origin of Species was published in 1859, it was not Vestiges but the quinary system which haunted Darwin’s thoughts.

Yet I assure you [Darwin wrote to the comparative anatomist Richard Owen about the idea of evolution by natural selection] that its truth has often & often weighed heavily on me: & I have thought that perhaps my book might be a case like Macleay’s Quinarian system. So strongly did I feel this, that I resolved to give it all up, as far as I could, if I did not convince at least 2 or 3 competent judges.

The quinary system was a cautionary tale, warning of the consequences of philosophical ideas about nature running ahead of tangible evidence.

Macleay’s reaction to Origin

When the Origin of Species was published in November 1859, Robert and Georgiana Lowe – who had returned to England a decade earlier – were eager to know their old Sydney friend’s opinion of this sensational book.

Macleay thanked the Lowes for giving him the subject of his letter. Little, if anything, could have interested Macleay so much. Ever mindful of circles, Macleay felt that he had ‘enjoyed the best part of that circle which it appears fated that mankind must go round’. So he confessed to Lowe, thick in the midst of English politics, that he found the subject of Darwin’s book ‘more interesting than either the extension of British commerce or even the progress of national education’. Macleay cut to the nub of the issue Darwin had sought to play down: ‘This question is no less than ‘What am I?’ ‘What is man? a created being under the direct government of his Creator, or only an accidental sprout of some primordial type that was the common progenitor of both animals and vegetables.’ Macleay was intrigued. The Mosaic account was all very well for Doctors of Divinity, but the naturalist was confronted by serious issues. The facts led to a choice of conclusions. One must believe in a special creation of organised species that had been progressive and was still in operation or else accept ‘some such view’ as Darwin’s where all the forms of animals and vegetables were derived from a primordial material cell of life. ‘Darwin, indeed, for no reason that I can perceive, except his fear of alarming the clergy, speaks of a Creator of the original material cell.’ But if that cell could ‘go on by itself’ developing into all the variety of plants and animals, past and future, then ‘there appears to be very little necessity for His existence’.

Macleay almost seems attracted by the argument. But then retreats. As Darwin seemed to admit that the primordial cell had a Creator, Macleay could not see the advantage of denying the Creator a continuing role in the management of life. Lamarck had viewed life as having existed ‘of itself from all eternity’ and so was more logical. Unlike the author of Vestiges, Lamarck and Darwin were both able naturalists, and though Darwin’s facts may not always be sound, ‘still, quite enough of them are so far unexceptionable as to entitle his lucubrations – however preposterous – to our respect, if not our assent’. Macleay built his case against Darwin’s theory. Human selection was true enough – ‘within certain limits assigned by the Creator’ – but as for natural selection, it was the same as Lamarck’s idea. The only original one of Darwin’s three types of selection was sexual selection ‘and if anyone can believe, that the sexes of every animal were originally alike: that the cock, for instance, owes his comb, wattle, and other distinguishing marks to the taste of the hens who have constantly sought such a type to breed from – why, all I can say is that such a believer must have a very wide swallow’.

For Macleay, as for so many in the face of Vestiges and later the Origin of Species, the naturalistic explanations were not compatible with deep-seated religious beliefs and an understanding of man’s special place in the scheme of things. As Milton Millhauser has pointed out in relation to Vestiges, people clung to the opinion of man’s separation from the animal kingdom ‘with something more than an intellectual conviction; religion was concerned in it, and a kind of rock-bottom human pride’. We can hardly wonder that Macleay, at the margins of scientific culture for more than twenty years, should have been reluctant to abandon his deepest religious convictions in favour of Darwin’s theory on a first reading. ‘I am myself so far a Pantheist that I see God in everything [Macleay informed Lowe]: but then I believe in His special Providence, and that He is the constant and active sole Creator and all-wise Administrator of the Universe.’ That Macleay did not understand natural selection and did not see how it differed from Lamarck’s mechanism of transformation is a matter of no surprise. Many of Darwin’s early supporters were persuaded of the truth of evolution but were sceptical of natural selection as its mechanism. What is remarkable is that despite his profoundest beliefs (and his own world-weariness) Macleay’s pleasure in delving into these questions is the most evident feature of his letter. However much he disagreed with Darwin’s conclusions, he welcomed his book. ‘Charles Darwin is an old friend of mine and I feel grateful to him for his work. I hope it will make people attend to such matters, and to be no longer prevented by the first chapter of Genesis from asking for themselves what the Book of Nature says on the subject of Creation.’

Conclusion

William Sharp Macleay died in Sydney in relative obscurity in 1865 (the year, incidentally, in which Alice in Wonderland was published). He was never photographed, so far as we know. There is only the sketch and a posthumous marble bust executed by Charles Summers in Rome (in the Linnean Society in London). In contrast, both Darwin and Wallace lived their later years in or near London and achieved growing fame. They were frequently photographed in old age, ancient, bearded and venerable. Macleay’s ideas were thoroughly eclipsed in the 1840s and he failed to produce the string of insightful and successful books which characterised both Darwin and Wallace in their later years. Macleay’s ideas remain little more than a quaint idiosyncrasy, while Darwin and Wallace gave us a framework of ideas in which biologists continue to work today.

While one cannot reduce creativity of thought to a mechanical formula, it is clear that several of the features I have examined were at least necessary to provide the context out of which that creativity could work its magic. Tantalising though it is to think that the circumstances were open for William Sharp Macleay to conceive of a nature shaped by evolution, and of the mechanism by which evolution occurred, it is clear that this could not be. Macleay was largely working in an eighteenth century mode of books and specimens. What was needed was an active immersion in the complexity of living nature in addition to the intellectual tools of library and cabinet.

Further reading on W.S. Macleay

Julian Holland, ‘Macleay, William Sharp (1792-1865)’, The Dictionary of Nineteenth-Century British Scientists (Bristol: Thoemmes Continuum, 2004), vol. 3. pp. 1307-11

Julian Holland, ‘Diminishing Circles: W.S. Macleay in Sydney 1839-1865’, Historical Records of Australian Science 11(2) (Dec 1996): 119-47

Uploaded March 2009

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