CHAPTER 2

Creating Order from Profusion

Albertus Seba (1665–1736), Locupletissimi Rerum, 1734–1765; Shells.

Renaissance and Enlightenment

(1700–1820)

Our modern understanding of the relationships between animals is rooted in three concepts that were gradually formulated in the years between 1750 and 1870.

The three ‘big ideas’ are evolution, or the concept that animal species change, split and diversify over time; the ancient earth, the theory that enormous geological timespans have allowed evolution to create the animal complexity and diversity around us; and natural selection, the mechanism now thought to cause this evolutionary change.

These theories did not appear simultaneously as a complete, interlinked triad, but instead arose piecemeal as evidence accumulated and the intellectual shackles of the religious past were progressively cast off. An all-powerful God might have needed only a week to create the unchanging fixity of his animal kingdom, and only a few thousand years to play out the world’s history, but by the Enlightenment many thinkers had realized that the Genesis narrative does not fit the evidence.

Maria Merian (1647–1717), Metamorphosis Insectorum Surinamensium, 1705 (see here); Spectacled caiman and false coral snake.

In retrospect, the eighteenth century was the pivotal time in the history of biology. Over a relatively brief period the seeds of doubt were sown in natural philosophers’ minds about the origins of all the animal diversity around them. Throughout this period new discoveries reported from around the globe added to a growing sense that animal forms are almost endless in their variety, and an ever-accumulating fossil record showed the animal kingdom to be immensely variable not only in the present, but also across past aeons.

As a result, over the course of the eighteenth century, the emphasis of zoological classification changed from a confident cataloguing of the finite, discrete products of God’s creation into an uncertain scramble to make sense of overwhelming animal variety. By the end of the period covered by this chapter, 1820, evolution and the ancient Earth were widely discussed – although natural selection would have to wait a little longer.

The idea of evolution is older than many realize, and some strikingly modern-sounding theories had already been proposed in scientific environments older, yet less theologically constrained, than eighteenth century Western Europe. Some ancient Greek philosophers suggested that life on Earth originally arose from non-living matter, that animal types change over time, and even that land animals are derived from aquatic ancestors. Furthermore, they speculated that fossils are remains of animals that met their demise in some ancient epoch, perhaps due to environmental cataclysms such as floods. Similarly, thinkers from the early Islamic world also proposed that animals change over time, and even that this was mediated by a ‘struggle for survival’ not unlike modern theories of natural selection. In addition, they suggested that past changes in animals had occurred in an impermanent world whose geography could change radically, so that what is now land might once have been sea, and vice versa.

Maria Merian (1647–1717), Caterpillars, Their Wondrous Transformation and Peculiar Nourishment from Flowers, 1679; The mulberry tree bears fruit.

In Western Europe a major step towards modern modes of animal classification was made in the late seventeenth century by John Ray, at St Catharine’s College in Cambridge, where the author of this book now works. Mainly remembered as the originator of the concept of a ‘species’, he also developed a methodical approach to the organization of living things according to their characteristics, and applied it across the plant and animal kingdoms. His neat nested lists of animal groupings do not imply an evolutionary process, and certainly cannot be interpreted as evolutionary trees, yet they reflect a newly objective form of scientific classification. For example, Ray argued on the basis of internal anatomy that whales are mammals and not fish, as many believed. He also attempted a comprehensive arrangement of insects based on their life cycles and mechanisms of metamorphosis.

Although more famous, the next phase of zoological organization could be argued to be conceptually retrogressive, even though it led to the development of a system of animal classification still in use today. The Swedish biologist Petri Artedi commenced this work in his posthumously published Philosophia Ichthyologia of 1738, when he developed a set of classificatory hierarchies akin to modern genera, families, orders and classes. His colleague Carl von Linné (often Latinized to ‘Linnaeus’) then extended Artedi’s ideas and applied them to other animals, plants and even minerals. The result was the compendious 1735 Systema Naturae (see here and 67), in which he sought to arrange all living and mineral things into a coherent classificatory system. Although all its gradations of classification (apart from the species) were arbitrary inventions rather than real natural phenomena, its neat filing of the sprawl of nature was so satisfying that we still use it, or at least a variant of it. Linnaeus also introduced the convenient binomial system of naming organisms by which humans, for example, are snappily termed Homo sapiens. In fact, Linnaeus’ dispassionate inclusion of humans in his scheme was itself one of his most scientifically important innovations.

The next major figure in this scientific revolution was Georges-Louis Leclerc, Comte de Buffon, a Frenchman who in the mid-eighteenth century pursued a wide range of intellectual enquiries in his compulsion to discover the origins and relatedness of life on Earth. He studied, not without controversy, the origin of the Earth, the origin of life from non-living matter, the cognitive abilities of animals, and the status of ‘lost’ species found in rocks but never encountered alive. He was also the first to subdivide the history of the Earth into a series of prehistoric eras. Indeed, he thought contemporary physics and palaeontology had revealed the Earth to be at least 50,000–70,000 years old – incomprehensibly ancient to those who believed what the Bible told them. He also noted that fossil animals are frequently buried in locations far distant from where similar living creatures roam today, so conjectured that animals change over time and that it is migration that causes them to do so. He even proposed that animals’ characteristics could be inherited by a non-spiritual mechanism, in response to exposure to new environments. As if that were not enough, Buffon was one of the first to create diagrams of interrelationships between animals. He formulated a ‘network’ of the similarities between dog breeds that appears very modern, although it does not look like an evolutionary tree – probably because, unlike wild species, dog breeds have not diverged to the point at which they can no longer interbreed. Long before genes or DNA, Buffon set the scene for modern biology.

John Ray (1627–1705), Synopsis Methodica, 1693; General table of the animals.

Thomas Pennant (1726–1798), British Zoology, 1776; Fitchet (polecat) and martin.

Thomas Bewick (1753–1828) A General History of Quadrupeds, 1790; The zebra.

In the late eighteenth century, the drift towards evolution and the ancient Earth continued. In his 1766 Elenchus Zoophytorum, the Prussian zoologist Peter Simon Pallas argued that the interrelationships of living things could not be represented by a metaphysically idealized linear scala, but that zoologists should instead use nets, or branching trees. He wrote of life as a tree trunk that had divided into two – plants and animals – with each hemi-trunk consisting of ‘generic’ species, giving rise to lateral twigs and branches of more specialized types. Disappointingly, it is not thought Pallas ever actually drew his tree.

Soon after, in 1785, James Hutton directly addressed the question of the age of our planet in his Theory of the Earth. He argued that most of the processes that shape the face of the planet are either slow, such as erosion and sedimentation, or infrequent, such as volcanism. Thus, for the Earth to have attained its present state it must be far older than several thousand years. This theme was later extended by the self-taught surveyor and geologist William Smith (see here) in his 1816 Strata Identified by Organized Fossils. Smith meticulously recorded the fossils found in sediments across Britain and realized that each rock layer or ‘stratum’ contains characteristic remains of its own distinctive, different fauna. He even discussed whether gaps in his fossil story represented simple incompleteness of the geological record, or ancient extinction events. The world was beginning to look more ancient than the human mind could easily contemplate.

The idea of a branching genealogical evolutionary tree (a ‘phylogenetic’ tree as it was named later in the eighteenth century) seems obvious now, yet biologists took decades to settle on it as their preferred classificatory format. This slowness probably reflects the fact that the now-ubiquitous tree shape implies things about animal origins and animal change that many were unwilling to accept.

Marcus Elieser Bloch (1723–1799), Ichthyologie ou Histoire Naturelle des Poissons, 1796; Carp (Cyprinus) species.

In fact, the first biological ‘classificatory tree’ was of plants, not animals. Augustin Augier’s ‘Arbre Botanique’ of 1801 (see here) was a systematic attempt to compare plants according to clearly defined criteria – although it was still not meant to demonstrate genealogy, nor even changes in plant forms over time. However, the tree motif was not solely decorative, and Augier gave much thought to whether plants share certain features because those features are directly equivalent between different species (akin to what we now call ‘homology’), or simply because species need similar structures to perform similar functions (‘analogy’). Thus, Augier pondered some subtle evolutionary issues, without even admitting that evolution occurs – and also hinted that a similar pictorial approach could be used for animals.

Eight years later, the first phylogenetic ‘tree’ of animals appeared – in subdued form – in Jean-Baptiste Lamarck’s Philosophie Zoologique (see here). Unlike Augier, Lamarck strongly believed that the patterns of organismal variation he observed could only be explained by evolution, so his trees were certainly meant to represent species change and species-splitting over time. He persisted with his trees and the later ones acquired more branches, and also more certainty, as tentative dotted lines were replaced by decisive black lines and braces. Unfortunately, Lamarck is now widely ridiculed for suggesting evolutionary processes that seem unlikely to modern ears. Although he correctly stated that the environment is an important driver of animal evolution, he thought it acts by changing the extent to which individual animals use different organs and tissues, and that this relative use or disuse of parts of the body could be inherited by offspring. He also clung to the old idea that there is an ideal of natural perfection towards which all organisms strive, even though in his mind this was by evolution rather than the determination of God or individual creatures. However, it is now often argued that Lamarck’s errors are unimportant compared to his espousal of the inheritance of characteristics by physical rather than spiritual means, and the profound effect his enlightened support of evolution was to have on biologists who came after him.

Georges Cuvier (1769–1832), Le Règne Animal, 1817; Skull of a cod.

John Ray (1627–1705), Three Physico-theological Discourses, 1693; Fossils.

Naturalist John Ray (see here) corresponded extensively about the nature of fossils, concluding they were indeed the remains of dead creatures, but he was uncertain whether these creatures died due to natural causes, or the biblical flood. Any fossils with no known modern equivalents were assumed to be related to contemporary animals as yet undiscovered.

William Derham (1657–1735) and Eleazar Albin (1690–1742), A Natural History of English Insects, 1720; Hawk moths.

Albin’s chosen artistic medium was watercolour and his usual subjects were birds and insects. The Natural History is a surprisingly accessible survey of a topic of overwhelming size.

Maria Merian

Metamorphosis of the Insects of Surinam

TIMELINE

1647: Maria Merian born

1675: First book published

1699–1702: Travels to Surinam

1705: Publication of Metamorphosis Insectorum Surinamensium

1717: Maria Merian dies

Maria Sibylla Merian was an inspirational woman. The most gifted of a talented family, the daughter of Matthäus Merian (see here), she was trained mainly in the medium of watercolour, which was thought more seemly for a woman than oils or engravings.

Almost as soon as she started painting plants and flowers, Maria depicted the insects that devour them. Indeed, her early career shows a clear trend of the plants becoming less prolific, and the insects more so. Her most prominent devourers are caterpillars, and their metamorphosis into butterflies appealed to the devout Maria, who saw them as a symbol of the transformational relationship between humans and God.

However, Maria was also an able scientist, recording a variety of entomological discoveries, as well as providing strong support for Francesco Redi’s recent refutation of the origin of insects from base matter by spontaneous generation (see here).

Having settled in the Netherlands, the enterprising Maria travelled with her daughter Dorothea to the tropical rainforests of Surinam, in South America, to indulge her passion for entomology. The results of their work was the stunning 1705 Metamorphosis Insectorum Surinamensium. Maria was clearly an astute businesswoman, as the book was made available in Dutch and Latin, in colour and monochrome, and also at reduced price to early purchasers.

Maria Merian (1647–1717), Metamorphosis Insectorum Surinamensium, 1705; Spiders.

Maria also wrote frankly and controversially about the conditions in the South American colonies – of how slaves employed suicide and toxin-induced abortions to avoid further suffering at the hands of the slaveholders.

Maria’s relative social and scientific freedom stand in contrast to how her work was criticized and neglected in the nineteenth century. One famous image (left) shows a giant spider having killed a hummingbird, something many thought to be feminine hyperbole, but that we now know to be accurate.

Maria Merian (1647–1717), Metamorphosis Insectorum Surinamensium, 1705; Butterflies and a caterpillar.

Thomas Boreman (1712–1785), A Description of Three Hundred Animals, 1730; Insects and arachnids.

Actually a children’s book, the Description draws heavily on the bestiary tradition by mixing the familiar, exotic and mythical in its review of three hundred creatures. Boreman was an innovative publisher of children’s books, and it is assumed he wrote this one.

Carl Linnaeus (1707–1778), Systema Naturae, 1735; Mineral kingdom.

Published just a few months after he left medical school, Systema Naturae (see here) was Linnaeus’ defining work. It introduced his new system of animal and plant classification, a scheme that was to be elaborated throughout the book’s many subsequent editions. Linnaeus perhaps overstretched the concept when, as here, he endeavoured to include minerals in his scheme.

Carl Linnaeus (1707–1778), Systema Naturae, 1735; The animal kingdom.

The centrepiece of Linnaeus’ obsessive filing of the living world, the Systema Naturae (see here), this table divides animals into quadrupeds, birds, amphibians, fish, insects and worms (‘vermes’). The inclusion of ‘paradoxa’ hints, however, at an admission that the author was not quite able to produce a comprehensive organization of the beasts.

Eleazar Albin (1690–1742), A Natural History of Birds, Volume 2, 1734; Albin’s macaw.

Albin’s macaw is known only from this one image, so is assumed to be extinct. Sadly, many New World psittacine species are known only from compendia created by eighteenth- and nineteenth-century zoologists.

Charles Bonnet (1720–1793), Traité d’Insectologie, 1745; Notion of a scale of living beings.

One of the most detailed expressions of the idea of the scala naturae (see here) appears in this entomological treatise by French naturalist-philosopher Charles Bonnet.

Georges-Louis Leclerc, Comte de Buffon (1707–1788), Histoire Naturelle, 1749; L’Unau (two-toed sloth).

Sloths are strange in many ways, and one of these is their classificatory relationship to other ‘placental’ (i.e. live-bearing, non-marsupial) mammals. In many modern classifications they are considered part of a ‘sister group’ that split early from the lineage leading to most other mammals. Leclerc (see here) was a key figure of the eighteenth-century scientific revolution.

Albertus Seba (1665–1736), Locupletissimi Rerum, 1734–1765; Shells.

The Dutch zoologist Albertus Seba compiled one of the largest biological collections then in existence, and published detailed catalogues of most of his specimens, too.

Louis Renard (c.1678–1746), Poissons, Écrevisses et Crabes, 1754; Fishes (above); Crustaceans (below).

Renard was an apothecary, publisher and spy, and also made time to be an ichthyologist. The full title of this book translates as ‘Fishes, crayfishes, crabs, of diverse colours and extraordinary forms, found around the Molluccas and on the coasts of the southern lands’. Some of the creatures depicted are real, but many seem to have been made up, including a mermaid. Also, their appearance becomes more fanciful as the book progresses.

Christianus Hoppius (dates unknown), Linnaeus’ Academic Delights, 1763; Anthropomorpha.

The origin of humans was a particular challenge to early anthropologists – partly because the lines between theology and science, myth and reality, and races and species had not yet been clearly drawn. This image, from a doctoral thesis published by Carl Linnaeus (see here), depicts Troglodyta bontu, Lucifer aldovandri, Satyrus tulpii and Pygmaeus edwardi. It is notable that the modern binomial name for the chimpanzee is still Pan troglodytes.

Thomas Pennant (1726–1798), British Zoology, 1776; Creeper and hoopo(e).

British Zoology was the most comprehensive catalogue of British fauna yet produced, but the cost of its beautiful engravings meant its author made no money from it. Pennant was much more than a cataloguer of animals, however, and corresponded widely with the natural philosophers of the day.

Otto Friedrich Müller (1730–1784), Zoologica Danica, 1779; Whales.

Only gradually were the affinities of whales elucidated. Even more than bats perhaps, cetaceans are the most dramatically specialized of all mammals. Although their ability to suckle their young had been known about for some time, many decades of diligent anatomical research were to pass until their origin was finally established – they are, in fact, most closely related to hippopotami.

James Newton (1748–1804), Dragonflies and mayflies (coloured engraving), 1780.

Most insects that retain wings possess four of them, and nowhere is this as obvious as in the Anisoptera, the dragonflies and their allies. Fossil evidence of the group pre-dates that of dinosaurs by approximately 100 million years.

Thomas Bewick (1753–1828), A General History of Quadrupeds, 1790; The walrus or sea-horse.

Bewick’s Quadrupeds is one of the most endearing zoological catalogues in existence, partly because of the emotions and personalities with which each animal is imbued. Some are proud, some wily, but the walrus is apparently the least cerebral.

Johann Kaspar Lavater (1741–1801) and Thomas Holloway (1748–1827), Essays on Physiognomy, 1789; Mammalian skulls.

Lavater was a proponent of the field of physiognomy, the idea that a person’s nature and personality can be discerned from the way they look. In his studies, he drew extensively from the facial structures of animals. Physiognomy was to become an important element of common preconceptions and misconceptions about race.

Johann Kaspar Lavater (1741–1801) and Christian von Mechel (1737–1817), Sequence from the head of a frog to the head of a primitive man (coloured etching), 1797.

Johann Kaspar Lavater (1741–1801) and Christian von Mechel (1737–1817), Sequence from the head of a primitive man to the head of Apollo Belvedere (coloured etching), 1797.

Charles White (1728–1813), An Account of the Regular Gradation in Man, and in Different Animals and Vegetables, 1799; The facial line of man, and different animals (above); Four different kinds of apes that approach nearest to man (below).

White was an English physician whose urge to support the old idea of the scala naturae or ‘great chain of being’ (see here) can make for unpleasant reading today. In the image above, he ranks animals and humans according to the verticality of their facial profile, from snipe and crocodiles, via dogs and non-European humans, to what he describes as ‘the model of the Graecian Antiques’. In the montage shown opposite are included ‘Dr Tyson’s pygmy’ (presumably this is an orang-utan), ‘a monkey’, a ‘native of Botany Bay’ and ‘an African’ – the latter two compared with the profile of ‘a European’.

Augustin Augier (1758–1825), Essai d’une Nouvelle Classification des Végétaux, 1801; ‘Arbre botanique’.

Augier’s ‘botanical tree’ was probably the first tree-shaped classification of living things (see here).

Jean-Baptiste Lamarck (1744–1829), Tableau Encyclopedique et Méthodique des Trois Règnes de la Nature, 1791; Sea urchins.

Lamarck (see here) is now best known for his support of the theory of evolution, but in his early career he was a more orthodox classifier of organisms.

Jean-Baptiste Lamarck

The Revolution of Evolution

TIMELINE

1744: Jean-Baptiste Lamarck born

1793: Appointed to Muséum National d’Histoire Naturelle

1801: Système des Animaux Sans Vertèbres published

1809: Philosophie Zoologique published

1829: Jean-Baptiste Lamarck dies

Jean-Baptiste Lamarck was one of many siblings born to an impoverished old noble French family in the mid-eighteenth century. At seventeen, Lamarck journeyed to the south of France where he enlisted as a soldier, but more important to posterity than his successful military career was the fascination he developed with the flora growing in the hot dusty soils of the south.

Lamarck subsequently embarked upon medical training, but was later encouraged to change career by his brother. He worked first at the Jardin des Plantes in Paris, where he published a weighty classification of the plants of France, in which the avid botanist-reader is encouraged to identify their specimens using dichotomous keys similar to those developed by John Ray (see here).

It was perhaps these forerunners of modern decision trees, as well as the vagaries of his career path, that led Lamarck to make his greatest contributions to biology (a term he himself coined).

Jean-Baptiste Lamarck (1744–1829), Histoire Naturelle des Animaux Sans Vertèbres (1815–1822); Presumed organization of the formation of animals.

When appointed a founding academic at the new Muséum National d’Histoire Naturelle, Lamarck found the major botany posts already filled by more esteemed professors, so he developed a new niche studying invertebrate animals. Intrigued by the striking similarities he observed between species, he soon became a supporter of the controversial idea that organisms change over time.

Lamarck was not the first to propose the idea of evolution, but his work was to be some of the most influential in the field. Daringly, he proposed that there are natural, physical forces that drive evolutionary change. Two forces, in fact: one inherent force that drives animals to attain higher levels of complexity over time, and a second environmental force that forces animal species to diversify from each other.

Jean-Baptiste Lamarck (1744–1829), Philosophie Zoologique, 1809; Chart showing the origins of different animals.

From Lamarck’s most important book, Philosophie Zoologique (see here), this humble chart – ‘Serving to Show the Origins of Different Animals’ – is probably the first evolutionary tree of animals ever drawn. It is actually an inverted tree, with its root in the worms (‘vers’) at the top, and a selection of egg-laying, hoofed and marine mammals at the bottom. This dichotomously branching tree, focusing on just a few selected groups, is surprisingly prescient of the austere taxonomic diagrams of the late twentieth century.

Sadly, Lamarck is now largely remembered for errors in the mechanisms he proposed – that simple life is continually spontaneously generated from inert matter, and that animals’ life experiences can affect the morphology of their offspring.

These errors now seem forgivable, made as they were in the pre-genetic, pre-molecular age, and Lamarck now stands out as the first thinker to seek testable hypotheses about the mechanisms underlying animal diversity.

Alexander von Humboldt (1769–1859), Ideen zu einer Geographie der Pflanzen, 1807; Geographie der Pflanzen in den Tropen-Ländern.

Although Humboldt studied mainly plants, he was influential in placing all organisms in their geographical context. Latitude, altitude, geographical proximity, meteorological variations – all affect which plants live where, and where plants live, so animals follow. Thus, Humboldt was a key figure in the origin of the modern science of biogeography (see Alfred Russel Wallace, Chapter 3, here). He also noted that the coastlines of some continents (for example, Africa and South America) are strangely complementary, and was thus a proponent of an early form of the theory of continental drift (see Alfred Wegener, Chapter 4, here).

Georg August Goldfuss (1782–1848), Über die Entwicklungsstufen des Thieres, 1817; System of Animals.

It sometimes appears that early-eighteenth-century biologists would go out of their way to avoid using a tree-like organizational scheme, with its controversial implications. Indeed, this egg-shaped diagram of animal classification by the Prussian palaeontologist Georg Goldfuss is an excellent example of such reticence. To the modern eye it resembles a Venn diagram, but is instead meant to depict similarities between animal groups, as well as an ascent to perfection – the capitalized words ascending the central axis are protozoa (single-celled animals), radiaia (anemones, sea cucumbers and others), mollusca, pisces (fish), mammalia and homo (man).

William Smith

The Principle of Faunal Succession

TIMELINE

1769: William Smith born

1801: Initial sketches for geological map of Britain

1816–1819: Strata Identified published

1817: Stratigraphical System published

1839: William Smith dies

Today, palaeontology and evolutionary biology are usually assumed to be aspects of the biological sciences, yet they have their roots firmly in geology. This is because, in the nineteenth century, geologists realized that the chronology of animal evolution is recounted in the regularly deposited strata of rocks. In other words, layered deposits are the ‘pages’ of the story of animal life.

An important figure in this realization – one of the key realizations in the entire history of science, indeed – was William ‘Strata’ Smith.

Britain was the ideal place to study the layering (stratification) of ancient rock deposits, for two reasons. First, its small area fortuitously contains an almost complete series of diagonally aligned strata from some of Earth’s oldest in northwest Scotland, to some of its youngest in England’s populous southeast. Second, geological knowledge was at a premium in eighteenth-century Britain, as the Industrial Revolution drove the digging of canals and the excavation of mines.

Coming from humble beginnings, William Smith worked for much of his life as a surveyor, and his work gradually convinced him that not only do fossil animals appear in certain strata – his ‘principle of faunal succession’ – but conversely that the presence of certain ‘diagnostic species’ could even be used practically to determine when strata had been deposited.

William Smith (1769–1839), A Delineation of the Strata of England and Wales, with part of Scotland, 1815.

In a few brief years, Smith published the first-ever national geological map, as well as two catalogues detailing the correspondences between mineral seams and their distinctive fossil captives: the Strata Identified and the Stratigraphical System.

Quite simply, our view of the world’s history would never be the same again. Yet Smith never benefitted personally from his discoveries. His flurry of richly illustrated publications bankrupted him; he spent time in a debtor’s prison, and died in poverty.

William Smith (1769–1839), Strata Identified by Organized Fossils, 1816–1819; Typical fossils found in the Greensand stratum.

William Smith (1769–1839), Stratigraphical System of Organized Fossils, 1817; Geological table of British organized fossils.

Georges Cuvier (1769–1832), Le Règne Animal, 1817; Crustaceans (above); and Théorie de la Terre, 1817; Teeth of the extinct mastodon, African elephant and Asian elephant, and the horn (antlers) of the fossil elk of Ireland (below).

Jean Léopold Nicolas Frédéric, Baron Cuvier, was an important figure in the development of modern modes of zoological organization. He expanded the classificatory system of Carl Linnaeus (see here), putting emphasis on the grouping of animals into large, overarching taxonomic groups. Importantly, he also incorporated fossil species into his system, and expounded the theory that periodic cataclysmic extinction events were important in the history of animal life. However, he did not support the developing theory of evolution.

Georges Cuvier (1769–1832), Le Règne Animal, 1817; Lizard, snake and frog (above); Birds (below).