Ernst Haeckel and the Theory of the Cell State: Remarks on the History of a Bio-Political Metaphor

See for instance Campbell Neil A. Reece Jane B. , Biology, 7th edn (San Francisco, 2005), 525–28. Leo Buss, The evolution of individuality (Princeton, 1987) is an extensive attempt to account for the origins of multicellularity which also assumes the basic correctness of Haeckel's colonial hypothesis.

For recent studies of Haeckel's philosophical outlook as a systematic whole see Kleeberg Bernhard , Theophysis: Ernst Haeckels Philosophie des Naturganzen (Cologne, 2005); Di Gregorio Mario , From here to eternity: Ernst Haeckel and scientific faith (Göttingen, 2005); and Richards Robert J. , The tragic sense of life: Ernst Haeckel and the struggle over evolutionary thought (Chicago, forthcoming 2008).

Canguilhem Georges , La connaissance de la vie, 2nd edn (Paris, 1969), 62. All translations are my own unless otherwise indicated.

Ibid., 70.

Mazzolini Renato , Politisch-biologische Analogien im Frühwerk Rudolf Virchows (Marburg, 1988); Weindling Paul J. , “Theories of the cell state in Imperial Germany”, in Biology, medicine and society, 1840–1940, ed. by Webster Charles (Cambridge, 1981), 99–155; Corsi Pietro Weindling Paul J. , “Darwinism in Germany, France, and Italy”, in The Darwinian heritage, edited by Kohn David (Princeton, 1985), 683–728 [section “Darwinism in Germany”, 685–98 by Weindling alone]; Weindling Paul J. , Health, race and German politics between national unification and Nazism, 1870–1945 (Cambridge, 1989); idem, “Ernst Haeckel, Darwinismus and the secularization of nature”, in History, humanity and evolution: Essays for John C. Greene, ed. by Moore J. R. (Cambridge, 1989), 311–27; and idem, Darwinism and Social Darwinism in Imperial Germany: The contribution of the cell biologist Oscar Hertwig (1849–1922) (Stuttgart, 1991). For more recent discussions of Virchow see the entry (“Virchow, Rudolf”) by Gordon McOuat in The reader's guide to the history of science, ed. by Hessenbruch Arne (London, 2000), 747–9; and Goschler Constantin , Rudolf Virchow: Mediziner — Anthropologe — Politiker (Cologne, Weimar and Vienna, 2002).

Weindling , “Darwinism in Germany” (ref. 5), 688. Daniel Gasman's earlier study, The scientific origins of National Socialism: Social Darwinism in Ernst Haeckel and the German Monist League (London, 1971), and his later Haeckel's monism and the birth of Fascist ideology (New York, 1998), push the ideological emphasis to an extreme. It is not my intention to deal here with Gasman's charges of Haeckel's racism or his alleged responsibility for Nazi atrocities. Those interested in this topic, however, may wish to review the recent exchange between Gasman and Robert J. Richards at the Ferris State University Institute for the Study of Academic Racism web-site: http://ferris.edu/HTMLS/staff/webpages/site.cfm?LinkID=259&eventID=34.

Pickstone John V. , “How might we map the cultural fields of science? Politics and organisms in Restoration France”, History of science, xxxvii (1999), 347–64.

Bölsche Wilhelm , Ernst Haeckel: Ein Lebensbild (Berlin and Leipzig, 1900), 25–28. Or see the English translation: Bölsche W. , Haeckel: His life and work, transl. by Joseph McCabe (London, 1906), 46–50. For more biographical details of Haeckel's scientific Bildung see Richards , op. cit. (ref. 2, forthcoming).

de Buffon Georges L. , Histoire naturelle, générale, et particulière, ii: Histoire générale des animaux (Paris, 1749), 24. See discussions in Farley John , Gametes & spores: Ideas about sexual reproduction 1750–1914 (Baltimore, 1982), 24–25, and in Canguilhem , La connaissance de la vie (ref. 3), 56–57.

Oken Lorenz , Die Zeugung (1805), quoted in Coleman William , Biology in the 19th century: Problems of form, function and transformation (New York, 1971), 25. The term ‘infusorian’ was coined by Martin Frobenius Ledermüller in 1763 and was commonly used by Lamarck and Cuvier. Cf. Churchill Frederick B. , “The guts of the matter. Infusoria from Ehrenberg to Butschli: 1838–1876”, Journal of the history of biology, xxii (1989), 1989–213, p. 189, n. 1. Oken's infusorians were mucus-vesicles, eternal units which survived the organism's death and lived on to compose new organisms; they are akin to Leibnizian monads. On this connection see Canguilhem , Connaissance (ref. 3). Hyman Libbie H. , The invertebrates: Protozoa through Ctenophora (New York, 1940), 44, writes that Georg August Goldfuss introduced the term ‘protozoa’ in 1818.

See Goethe's Zur Morphologie, from the second introductory essay “Die Absicht eingeleitet” (1817). My thanks to Ernst Hamm and Robert J. Richards for identifying for me the original source.

The physician and theoretical anatomist Johann Christian Reil in 1795 compared the arrangement of organs in the animal body to a “large republic”. See Richards Robert J. , The romantic conception of life: Science and philosophy in the Age of Goethe (Chicago, 2002), 260–1. I am grateful to Bob Richards for drawing my attention to Reil.

Schleiden Matthias , Contributions to phytogenesis, transl. by Smith Henry (London, 1847), 231–2. In the early part of the nineteenth century plants were commonly thought to be such compound individuals. See Elwick James , “The question of compound individuality in nineteenth century natural history”, in Auger J.-F. (ed.), Une image kaléidoscopique de sciences et techniques: Actes du Colloque Ontario-Québec en Histoire et Sociopolitique des Sciences et Techniques (Montréal, 13 janvier 2001) (Montreal, 2001), 17–32, pp. 25f.

Schleiden , Contributions to phytogenesis (ref. 13), 232.

Schwann Theodor , Microscopical researches into the accordance in the structure and growth of animals and plants, transl. by Smith Henry (London, 1847), 2.

Ibid., 190.

Ibid., 2.

Mazzolini , Politisch-biologische Analogien im Frühwerk Rudolf Virchows (ref. 5) is an extensive study of Virchow's use of social metaphor and analogy.

Virchow Rudolf , “Cellular-Pathologie”, Archiv für pathologische Anatomie und Physiologie und für klinische Medicin, viii (1855), 3–39, p. 25, quoted in Owsei Temkin, “Metaphors of human biology”, in Science and civilization, ed. by Stauffer Robert C. (Madison, 1949), 169–94, p. 175. Elsewhere Virchow uses the phrases, “Free state of equal individuals”, “Federation of cells”, and “Democratic cell state”. See Mazzolini , Politisch-biologische Analogien (ref. 5), chap. 3 for extensive samples of Virchow's social and political metaphors.

Virchow Rudolf , “Atoms and individuals” [1859], reprinted in Disease, life, and Man: Selected essays by Rudolf Virchow, transl. and with an introduction by Lelland J. Rather (Stanford, 1958), 120–41, p. 124, italics in original.

Virchow , “Atoms and Individuals” (ref. 20), 130.

Temkin , “Metaphors of human biology” (ref. 19); Ackerknecht Erwin H. , Rudolf Virchow: Doctor, statesman, anthropologist (Madison, 1953); Mazzolini , Politisch-biologische Analogien (ref. 5); Otis Laura , Membranes: Metaphors of invasion in nineteenth-century literature, science, and politics (Baltimore, 1999); and Goschler , Rudolf Virchow (ref. 5). Temkin , “Metaphors of human biology” (ref. 19), also mentions in this regard Ernst Hirschfeld, “Virchow”, Kyklos, ii (1929), 1929–16, but I have not been able to locate a copy.

Virchow discusses such colonial organisms as had been previously treated by Vogt Carl , Untersuchungen über Thierstaaten (Frankfurt am Main, 1851) and Leuckart Rudolf , Über den Polymorphismus der Individuen oder die Erscheinungen der Arbeitstheilung in der Natur (Giessen, 1851), in Virchow , “Atoms and individuals” (ref. 20), 120–41.

Kölliker Albert , Beiträge zur Kenntniss der Geschlechtsverhältnisse und der Samenflüssigkeit wirbelloser Thiere (Berlin, 1841); Jones Thomas W. , “Report on the changes in blood in inflammation and on the nature of the healing process”, British and foreign medico-chirurgical review, xviii (1844), 1844–80; and Remak Robert , Untersuchungen über die Entwickelung der Wirbelthiere (Berlin, 1850–55). See Harris Henry , The birth of the cell (New Haven, 1999) for historical details. The Austrian pathologist Salomon Stricker claimed in his Handbuch der Lehre von den Geweben des Menschen und der Thiere (Leipzig, 1871), i, 12, that he was the first to demonstrate that the developing embryo arises from the movement (Wanderung) of the individual embryonal cells in a paper published in the Wiener Sitzungsberichte in 1864.

See letter to his parents, 16 November 1853, in Haeckel Ernst , Ernst Haeckel: Biographie in Briefen, ed. by Uschmann Georg (Leipzig, 1983), 28–30.

Brücke Ernst , “Die Elementarorganismen”, Sitzungsberichte der kaiserlichen Akademie der Wissenschaften, xliv (1861), 381–406. Brücke's analogy was between cells and the chemical elements, those units which had so far resisted reduction to simpler arrangements of matter preserving the relevant physical and chemical properties. As the word ‘elementary’ often carries the association of being ‘simple’, Brücke's term might best be translated as ‘elemental organisms’, for he left open the possibility that cells might themselves prove to have a complicated internal organization.

Haeckel Ernst , Die Lebenswunder (Stuttgart, 1904), 167.

Haeckel Ernst , De Rhizopodum finibus et ordinibus (Berlin, 1861).

The British anatomist Richard Owen (1804–92) had noted even earlier analogies of form between ciliated human epithelial cells and ciliated protozoa. See Owen Richard , Lectures on the comparative anatomy and physiology of the invertebrate animals, delivered at the Royal College of Surgeons, 2nd edn (London, 1855).

Haeckel Ernst , De telis quibusdam astaci fluviatilis [On the tissues of river crabs] (Berlin, 1857); and idem, Die Radiolarien: Eine Monographie mit einem Atlas von fünf und dreißig Kupftertafeln (Berlin, 1862), 104–6. Kölliker reproduced illustrations of the amoeboid motion of blood cells from a crab taken from research for Haeckel's doctoral dissertation in Albert Kölliker, Handbuch der Gewebelehre des Menschen: Für Aerzte und Studirende, 5th edn (Leipzig, 1863), 46, Fig. 9.

Schultze Max , “Über Muskelkörpchen und das was man eine Zelle zu nennen habe”, Archiv anatomische physiologische wissenschaftlich Medicin, i (1861), 1–27, p. 9. See Reynolds Andrew , “Amoebae as exemplary cells: The protean nature of an elementary organism”, Journal of the history of biology, (2007), forthcoming.

Haeckel Ernst , “Ueber die Entwickelungstheorie Darwin's”, reprinted in Gesammelte populäre Vorträge aus dem Gebiete der Entwickelungslehre (Bonn, 1878), i, 1–28, p. 27. Haeckel agreed that possession of a nucleus was a necessary condition for being a true cell; but the Monera (or cytodes) he considered to be a group of unicellular “organisms without organs” lacking a nucleus, examples of which included bacteria and the amoeba he dubbed Protamoeba. The latter was eventually found to have a nucleus by later investigators.

Haeckel Ernst , Die generelle Morphologie der Organismen: Allgemeine Grundzüge der organischen Formen-Wissenschaft, mechanisch begründet durch die von Charles Darwins reformierte Deszendenz-Theorie (2 vols, Berlin, 1866).

Others had proposed the idea of a third kingdom before Haeckel introduced his Protista in 1866; for instance Richard Owen in 1859 (the Protozoa), John Hogg in 1860 (the Protoctista), and Thomas B. Wilson and John Cassin in 1863 (the Primalia). Rothschild Lynn J. , “Protozoa, Protista, Protoctista: What's in a name?”, Journal of the history of biology, xxii (1989), 277–305.

By ‘antimeres’ Haeckel meant the morphological counterparts of radially or bilaterally symmetrical organisms (e.g. the five rays of a sea star, the left and right half of a human); metameres are sequences of repeated units such as the jointed segments in annelids or the disks of the vertebrate column. Haeckel argued that metazoans (or tissue-forming animals) are composed of morphologically independent cells, but physiologically the cells are subordinated to the total organism, which itself constitutes an individual of a higher order. See Haeckel , Generelle Morphologie (ref. 33), i, 239–374. Ruth Rinard, “The problem of the organic individual: Ernst Haeckel and the development of the biogenetic law”, Journal of the history of biology, xiv (1981), 249–75, offers a helpful explanation of Haeckel's theory of organic individuality.

The idea of a physiological division of labour was introduced by the Belgian-English zoologist Henri Milne-Edwards (1800–85). Limoges Camille , “Milne-Edwards, Darwin, Durkheim and the division of labour: A case study in the conceptual exchanges between the social and the natural sciences”, in The natural sciences and the social sciences, ed. by Cohen I. B. (Dordrecht, 1994), 317–43; and Young Robert M. , “Darwinism and the division of labour”, Science as culture, ix (1990), 1990–24.

Haeckel , Generelle Morphologie (ref. 33), i, 362. See also the theses on tectological differentiation and centralization, i, 370–2.

Haeckel Ernst , Über Arbeitstheilung in Natur- und Menschenleben (Berlin, 1868), 140.

Earlier, however, in his 1863 speech (ref. 32), p. 26, in which he first publically came out in support of Darwin, Haeckel credited the mechanism of natural selection with explaining the phenomenon of the division of labour. Also in the ninth edition of Natürliche Schöpfungsgeschichte (1898) the processes of progressive division of labour and differentiation of parts (polymorphism) are both described as “the necessary consequences of natural selection in the struggle for life”; Haeckel Ernst , Natürliche Schöpfungsgeschichte, 9th edn (Berlin, 1898), i, 262.

Haeckel , op. cit. (ref. 33), i, 264, 270.

Haeckel Ernst , Natürliche Schöpfungsgeschichte. Gemeinverständliche wissenschaftliche Vorträge über die Entwicklungslehre im Allgemeinen und diejenige von Darwin, Goethe und Lamarck im Besonderen, über die Anwendung derselben auf den Ursprung des Menschen und andere damit zussamenhängende Grundfragen der Naturwissenschaften (2 vols, Berlin, 1868), i, 246.

For a history of Siphonophore studies see Winsor Mary P. , “A historical consideration of the Siphonophores”, Proceedings of the Royal Society of Edinburgh, B lxxiii (1972), 315–23.

Haeckel Ernst , Zur Entwickelungsgeschichte der Siphonophoren, Beobactungen über die Entwickelungsgeschihcte der Genera Physophora, Crystallodes, Athorybi, und Reflexionen über die Entwickelungsgeschichte der Siphonophoren im Allgemeinen. Eine von der Utrechter Gessellschaft für Kunst und Wissenschaft gekrönte Presisschrift, mit vierzehn Tafeln (Utrecht, 1869), 73.

For an example of how the history of embryology has overlooked Haeckel's cleavage experiments see Gilbert Scott F. , Developmental biology, 7th edn (Sunderland, MA, 2003), 61. According to Haeckel's secretary and biographer, Heinrich Schmidt, the founder of the Entwicklungsmechanik movement in embryology Emil Roux (also a former student of Haeckel's) regarded Haeckel's discovery a “Goldfund“that even in 1905 remained unremarked and unappreciated. Was Wir Ernst Haeckel Vedanken: Ein Buch der Verehrung und Dankbarkeit, ed. by Schmidt Heinrich (2 vols, Leipzig, 1914), i, 69.

Haeckel Ernst , Anthropogenie oder Entwicklungsgeschichte des Menschen: Gemeinverständliche Vorträge über die Grundzüge der menschlichen Keimes- und Stammes-Geschichte (2 vols, Leipzig, 1874), i, 97. My thanks to Matthias Bierenstiel for his assistance in translating the archaic German term Lebens-heerd.

Haeckel , Anthropogenie (ref. 45), 117–18.

Ibid.

Haeckel , Anthropogenie (ref. 45), 118–20.

See for instance Haeckel , op. cit. (ref. 41), 246.

Haeckel , Anthropogenie (ref. 45), 387–8.

Haeckel , Anthropogenie (ref. 45), 120.

From the Greek koinos meaning ‘common’; a coenobite, for comparison, is a member of a monastic community.

Haeckel Ernst , “Ueber die Wellenzeugung der Lebenstheilchen oder die Perigenesis der Plastidule”, reprinted in Gesammelte populäre Vorträge aus dem Gebiete der Entwickelungslehre (2 vols, Bonn, 1879; 1st edn, Berlin, 1876), ii, 36.

Haeckel , “Perigenesis der Plastidule” (ref. 53), 36.

Haeckel Ernst , Das Protistenreich: Eine populäre Uebersicht über das Formengebiet der niedersten Lebewesen (Leipzig, 1878), 16–17; idem, Die Lebenswunder: Gemeinverständliche Studien über biologische Philosophie (Stuttgart, 1904), 431; and idem, “‘Zellseelen und Seelenzellen’, Vortrag gehalten am 22. März 1878 in der ‘Concordia’ zu Wien”, in Gesammelte Populäre Vorträge aus dem Gebiete der Entwickelungslehre, i (Bonn, 1878), 143–81, pp. 157, 179.

Haeckel , “Zellseelen und Sellenzellen” (ref. 55), 176.

Blackbourn David , History of Germany 1780–1918: The long nineteenth century, 2nd edn (Malden, MA, 2003), 169, 198.

Though it seems rather perverse to blame, as Haeckel later did, the socialists of the Paris Commune for all the bloodshed involved in its overthrow. See Haeckel Ernst , Freedom in science and teaching, English transl. with a prefatory note by Huxley T. H. (New York, 1879), p. xxvii.

Haeckel Ernst , Arabische Korallen: Ein Ausflug nach den Korallenbänken des Rothen Meeres und ein Blick in das Leben der Korallenthiere, populäre Vorlesung mit wissenschaftlichen Erläuterungen (Berlin, 1876), 20, quoted in Bernhard Kleeberg, Theophysis: Ernst Haeckels Philosophie des Naturganzen (Cologne, 2005), 204. The artistic frontispiece of this work bears the date 1875 but the publication date is 1876.

Weindling , Health, race and German politics (ref. 5), 29–30.

Virchow Rudolf , Die Freiheit der Wissenschaft im modernen Staat (Berlin, 1877). For an interesting analysis of the debate and the larger issues at stake see Amidon Kevin , “‘A mighty fortress of free thought’: The biological sciences between discipline and public in the 1877–78 Virchow—Haeckel Debate”, paper (not yet published) presented at the fifth joint meeting of the History of Science Society, Canadian Society for History and Philosophy of Science, and the British Society for History of Science conference in Halifax, Nova Scotia, Canada, August 2004.

Weindling , op. cit. (ref. 5), 260.

Virchow , Die Freiheit der Wissenschaft (ref. 61), 12.

Haeckel Ernst , Freie Wissenschaft und Freie Lehre, eine Entgegnung auf Rudolf Virchow's München Rede über “Die Freiheit der Wissenschaft im modernen Staat” (Stuttgart, 1878); and idem, Freedom in science and teaching (ref. 58).

Haeckel , Freie Wissenschaft (ref. 64), 48.

Haeckel , Free science (ref. 58), pp. xxiv–xxv.

Haeckel , Naturliche Schopfungsgeschichte (ref. 41), 240–1.

Haeckel , Free science (ref. 58), pp. xxix–xxx.

E.g. Weindling , “Theories of the cell state” (ref. 5); idem, Health, race, and German politics (ref. 5), 47; idem, “Ernst Haeckel, Darwinismus and the secularization of nature” (ref. 5), 320–2; and Kleeberg , Theophysis (ref. 2), 203–7. For an especially critical portrayal of Haeckel as a proto-Nazi see Gasman's Daniel The scientific origins of National Socialism and Haeckel's monism and the birth of Fascist ideology (ref. 6). For response to Gasman's reading see Kelly Alfred , The descent of Darwin: The popularization of Darwinism in Germany, 1860–1914 (Chapel Hill, 1981), 120–1, and Richards , The tragic sense of life (ref. 2).

Weindling , Health, race and German politics (ref. 5), 31.

Richards Robert J. , “The foundation of Ernst Haeckel's evolutionary project in morphology, aesthetics, tragedy”, in The many faces of evolution in Europe, 1860–1914, ed. by Kemperink Mary Dassen Patrick (Amsterdam, 2004).

Brief Nr. 72, Paris, 20.4.1860, in Haeckel Ernst , Italienfahrt: Briefe an die Braut, ed. by Schmidt Heinrich (Leipzig, 1921). The letter also appears in Ernst Haeckel, Ernst Haeckel: Biographie in Briefen, ed. by Uschmann Georg (Leipzig, 1983), 67–68.

Haeckel , Biographie in Breifen (ref. 72), 89. Haeckel is referring to the build up to the seven weeks war between Prussia and Austria, during which Bismarck baited the Austrians into hostility, as he would do with the French four years later.

Haeckel , Free science (ref. 58), 110–19. For the contrast between morphological studies at Berlin and other German universities see Nyhart Lynn K. , Biology takes form: Animal morphology and the German universities, 1800–1900 (Chicago, 1995), 157, 174, 317ff.

Haeckel , Free science (ref. 58), 120.

Haeckel , Die Lebenswunder (ref. 55), 556.

Kleeberg , Theophysis (ref. 2), 203–7.

The passage in question is Haeckel , Die Lebenswunder (ref. 55), 472. The higher the state as a “unity to a higher whole … through progressive division of labour develops, the closer the reciprocal needs of the differentiated individuals become, the higher climbs the objective worth of the latter for the whole, but at the same time the more does the subjective worth of the individuals sink”. Quoted in Kleeberg , Theophysis (ref. 2), 206.

I am grateful to Cornelius Borck for communicating this insight to me.

Haeckel , Die Welträtsel: Gemeinverständliche Studien über monistische Philosophie. Volksausgabe mit Nachträgen zur Begründung der monistischen Weltenschauung (Leipzig, 1908; 1st edn, Bonn, 1899), 160.

Weindling , “Ernst Haeckel, Darwinismus and the secularization of nature” (ref. 5), 324–35, does insist, against Gasman, that Haeckel needs to be considered within the context of Wilhelmine Germany, rather than in a nascent Nazi Germany. Weindling also writes, “Haeckel's Social Darwinism did not seek to brutalize politics or to glorify imperialism in its militarist form. It expressed a type of cultural imperialism, in which Germany had a civilizing mission to the rest of mankind”, Weindling , Health, race and German politics (ref. 5), 57.

Ackerknecht Erwin H. , Rudolf Virchow: Doctor, statesman, anthropologist (Madison, 1953), 188, mentions that, although he opposed Bismarck's attempt to outlaw the social democratic party, Virchow confessed at this time (1878) that he was no longer a democratic revolutionary.

Haeckel Ernst , Kunstformen der Natur (Wiesbaden, 2004 [1899–1904]), fig. 6, Tafel 31, on p. 71, with description on p. 72.

Richards Robert J. , “Ernst Haeckel and the struggles over evolution and religion”, Annals of the history and philosophy of biology, x (2005), 89–115, pp. 95–96. Haeckel , Die Welträthsel (ref. 80), 134.

Canguilhem , Connaissance de la vie (ref. 3), 70.

For a discussion of the relationship between physiological and political opinions about the relation of parts to whole and the construction of animal and social bodies see Pickstone John V. , “How might we map the cultural fields of science? Politics and organisms in Restoration France”, History of science, xxxvii (1999), 347–64.

See for instance Haeckel Ernst Eucken Rudolf , “Germany's culture: Philosophers Eucken and Haeckel appeal to American scholars”, The New York Times, 25 September 1914; and Haeckel Ernst , “Ernst Haeckel gives Germany's peace terms: Celebrated German scientist also discusses the probable effect of the present war upon social progress throughout the world”, The New York Times, 19 March 1916. In the latter article Haeckel does insist on the need for German colonial expansion, echoing (though not explicitly voicing) the notion of Lebensraum of the German ethnographer Friedrich Ratzel (1844–1904). Hitler and the National Socialists of course would make this a major component of their political agenda. Those sympathetic to Daniel Gasman's reading of Haeckel may be inclined to view this as further evidence of Haeckel's influence upon later Nazi policy. Whether this shows that Haeckel had a direct and reasonably foreseeable impact upon later events, and hence is morally culpable for them, is another matter.

Witness his remarks about the effects of “the centralization of science” in Haeckel , Freedom in science and teaching (ref. 58), 119. The last chapter of this work is titled “Ignorabimus et restringamur” in reference to DuBois-Reymond's 1872 lecture on the supposedly inherent limits of science and Virchow's 1877 lecture imploring scientists to restrict themselves from speculation.

See the discussion on “Empirie und Philosophie” (beginning with quotations from Goethe and Müller) and those following in chap. 4 (“On the method of morphology of organisms”) in Haeckel , Generelle Morphologie (ref. 33), i, 63–87.

Haeckel received offers from the universities in Vienna (1870 and 1872), Strasbourg (1872), and Bonn (1874). One might argue though, noting that all these offers occurred several years before he became such a controversial public figure, that he really had little choice but to remain in Jena.

Spencer Herbert , Social statics; or, the conditions essential to human happiness specified, and the first of them developed, English re-issue of 2nd edn (London, 1868 [1850]), 493.

Duncan David , The life and letters of Herbert Spencer (London, 1911), App. B, 540.

For more on Spencer's theory of the social organism see Hilts Victor L. , “Towards the social organism: Herbert Spencer and William B. Carpenter on the analogical method”, in Cohen (ed.), The natural sciences and the social sciences (ref. 36), 275–303, and Elwick James , “Herbert Spencer and the disunity of the social organism”, History of science, xli (2003), 35–72.

Spencer Herbert , “Progress: Its law and cause”, Westminster review, lxvii (1857), 445–85.

Weindling , Health, race and German politics (ref. 5), 42.

Ibid. For Spencer's discussion of organic integration see Spencer Herbert , Principles of biology (2 vols, London, 1865), i, 160–4, and ii, 365–76.

Haeckel—Spencer correspondence at the Ernst-Haeckel-Haus, Friedrich Schiller Universität in Jena. My thanks to Dr Thomas Bach for his assistance with these letters.

Senate House Library, University of London, MS 791/73. My thanks to Mr Alun Ford for making photocopies of these letters available to me.

Haeckel , Generelle Morphologie (ref. 33), i, 372.

See Leuckart , Polymorphism (ref. 23) and Vogt , Untersuchungen über Thierstaaten (ref. 23). For more details about the significance of the Siphonophora for discussions of organic individuality see Winsor , “A historical consideration of the Siphonophores” (ref. 42).

Haeckel , Über Arbeitstheilung (ref. 38).

Leuckart , op. cit. (ref. 23), 10; and Vogt , op. cit. (ref. 23), 29ff.

For Goethe's influence on Haeckel's development and his general Weltanschauung see Bölsche , Ernst Haeckel: Ein Lebensbild (ref. 8), 21–25; and Richards Robert J. , “If this be heresy: Haeckel's conversion to Darwinism”, in Darwinian heresies, ed. by Lustig Abigail Richards Robert J. Ruse Michael (Cambridge, 2004), 101–30, and idem, The tragic sense of life (ref. 2).

“Freut euch des wahren Scheins,/ Euch des ernsten Spieles,/ Kein Lebendiges ist Eins,/ Immer ist's ein Vieles.” Haeckel , Generelle Morphologie (ref. 33), i, 241. Roughly translated: “It pleases you to keep up appearances, for you the serious stakes, No living thing is one, always is it a many.” My thanks to Thomas Bouman for checking my translation of these lines.

Haeckel , Generelle Morphologie (ref. 33), i, 322, n. 1.

Weindling , “Darwinism in Germany” (ref. 5), 694–5, and idem, Darwinism and Social Darwinism in Imperial Germany (ref. 5), 20.

See Richards Robert J. , Darwin and the emergence of evolutionary theories of mind and behavior (Chicago, 1987), 268; Young , op. cit. (ref. 36), 168; and Hilts , op. cit. (ref. 93), 298. Elwick, “Herbert Spencer and the disunity of the social organism” (ref. 93), 49–50, argues that Spencer was already familiar with the principle of the physiological division of labour from reading Harriet Martineau's Illustrations of political economy (1832–34) as a boy.

In fact Milne-Edwards's name does not appear in Haeckel , Über Arbeitstheilung (ref. 38), although it does in Haeckel , Generelle Morphologie (ref. 33), i, n. 1, 322.

Haeckel , “Perigenesis der Plastidule” (ref. 53), 37.

Ibid., 36.

Ibid., 37.

See also Haeckel , Generelle Morphologie (ref. 33), i, 362, and idem, Über Arbeitstheilung (ref. 38), 130: “The apparent life-unity of every multicellular organism is, just as with the political unity of every human state, the composite result of the association and division of labour of these little citizens [the cells]”.

Haeckel , “Ueber die Entwickelungstheorie Darwin's” (ref. 32), 4.

Weindling , op. cit. (ref. 5). Robert Richards, on the other hand, has been arguing for a while now that Haeckel hardly had to introduce these romanticist elements into Darwin's theory, since they were already there to begin with. See Richards's books The meaning of evolution: The morphological construction and ideological reconstruction of Darwin's theory (Chicago, 1992), and The romantic conception of life: Science and philosophy in the Age of Goethe (Chicago, 2002).

Haeckel , “Perigenesis der Plastidule” (ref. 53), 64.

Wilson Edmund B. , The cell in development and inheritance, 3rd edn (New York, 1928 [1896]), 102.

Reynolds Andrew , “The theory of the cell-state and the question of cell autonomy in nineteenth and early twentieth century biology”, Science in context, xx (2007), 71–95.

On reactions to Haeckel's strong version of the recapitulationist thesis in embryology, and his controversial embryo drawings, see Hopwood Nick , “Pictures of evolution and charges of fraud: Ernst Haeckel's embryological illustrations”, Isis, xcvii (2006), 260–301; and the essays in From embryology to evo-devo: A history of developmental biology, ed. by Laubichler Manfred D. Maienschein Jane (Cambridge, MA, 2007).

Ruse Michael , Monad to Man: The concept of progress in evolutionary biology (Cambridge, MA, 1996).

For examples of the metaphor in modern popular science see Cudmore L. L. Larison , The center of life: A natural history of the cell (New York, 1977); Rensberger Boyce , Life itself: Exploring the realm of the living cell (New York, 1996); and Harold Franklin M. , The way of the cell: Molecules, organisms, and the order of life (Oxford, 2001).

La Vergata Antonella , “Images of Darwin: A historiographic overview”, in Kohn (ed.), The Darwinian heritage (ref. 50), 901–72, p. 939.

Pickstone , “How might we map the cultural fields of science?” (ref. 7).

Ibid., 353.