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Darwin Correspondence Project

From Ernst Haeckel1   9 May 1876

Jena

9 Mai 1876

Hochverehrter Freund!

Noch niemals habe ich Ihnen mit solcher Furcht und Zaghaftigkeit geschrieben, wie heute. Denn ich trete durch die beifolgende Schrift über “die Perigenesis der Plastidule” zum ersten Male (und hoffentlich auch letzten Male!) einer Ihrer Ansichten entgegen.2 Freilich handelt es sich ausschliesslich um die “provisorische Hypothese der Pangenesis”, von welcher die Descendenz-Theorie und Ihre eigene Selections-Theorie ganz unabhängig ist.3 Aber trotzdem ist es mir sehr schwer geworden, auch nur in einem einzigen untergeordneten Punkte Ihren geistreichen Ansichten irgendwie zu opponiren.

Sie werden wohl bemerkt haben, dass ich in meinen bisherigen Schriften—namentlich auch in der “Anthropogenie” und “Natürlichen Schöpfungsgeschichte”4 Ihre Pangenesis ganz mit Stillschweigen übergangen habe, und zwar bloss desshalb, weil ich von Anfang an mich nicht damit befreunden konnte.

Als Sie nun kürzlich die Güte hatten, mir die II. Edit. Ihres ausgezeichneten Werkes über “Variation under Domestication” zu überschicken, und mich besonders auf die verbesserte Darstellung der “Pangenesis” aufmerksam zu machen, fühlte ich mich verpflichtet, meine Gründe dagegen aus einander zu legen und mein bisheriges Stillschweigen darüber zu erklären.5

Wenn Sie die Güte haben wollten, gelegentlich in einer Musse-Stunde sich den Versuch über die provisorische Hypothese der Perigenesis anzusehen, so würde ich Sie bitten, zunächst die blau angestrichenen Stellen zu beachten.6 Auf pag. 70 habe ich den Unterschied und Gegensatz zwischen Ihrer Pangenesis und meiner Perigenesis möglichst scharf formulirt. Im Vordergrunde meiner Hypothese stehen folgende Elemente derselben: 1, Das mechanische Princip der übertragenen Molecular-Bewegung, 2, Die active Thätigkeit des Plasson (in den Zellen Protoplasma + plus Nucleus), 3, Das Gedächtniss oder die Reproductionskraft der Plastidule (der Plasson-Moleküle, als einziger activer, lebendiger Gewebs–Elemente).7

Ich bekenne Ihnen offen, dass ich nicht im Stande bin, die Pangenesis mit den Thatsachen der Histologie— oder richtiger gesagt, mit meiner Auffassung der Zellen-Theorie und mit der Plastiden-Theorie zu vereinbaren. Über letztere habe ich in meinen biologischen Studien über Moneren und andere Protisten mich ausführlich ausgesprochen.8 Wie bei der Pangenesis die Gemmulae der ganzen Ahnen-Reihe im Sperma und im Ei sich ordnen und wieder zur organisirten Form-Bildung in den Descendenten kommen sollen, vermag ich nicht zu begreifen; mir scheint daraus nothwendig eine Einschachtelung der Keime und theilweise Praeformation zu folgen. Verzeihen Sie mir diese offenen und aufrichtigen Einwürfe!

Neben der herzlichen Bitte um nachsichtige Aufnahme der “Perigenesis” trage ich Ihnen heute gleich noch ein zweites Gesuch vor, die Bitte um Verzeihung dafür, dass ich Ihnen die beifolgende “Geographie botanique” aus der “Histoire naturelle des Iles Canaries” von Webb und Berthelot erst heute zurücksende.9 Sie hatten die Güte gehabt, mir dieses Werk im October 1866, als ich das Glück hatte, Sie in Down besuchen zu dürfen, mit auf die Reise nach den Canarischen Inseln zu geben und es hat mir auf Teneriffa und Lanzarote sehr gute Dienste geleistet.10 Nach der Rückkehr hatte ich es zufällig verlegt und fand es erst kürzlich zwischen einen Haufen von Bildern und Blättern in einer bei Seite gelegten Mappe wieder. Verzeihung bitte ich für diese Unordnung, und herzlichen Dank sage ich für das geliehene Werk. Ebenso den freundlichsten Dank für die II Aufl. der “Variation”— Ich bin gegenwärtig mit der Umarbeitung der III. Aufl. der “Anthropogenie” beschäftigt, welche wesentlich zu verbessern ist. Ich hoffe, sie Ihnen noch im Laufe dieses Jahres senden zu können.11 Ausserdem kann ich fast Nichts arbeiten, da ich zu Ostern das Prorectorat der Universität Jena übernommen habe und fast den ganzen Tag durch Amts-Geschäfte Schreiberei und Vorlesungen absorbirt bin.12

Hoffentlich geht es Ihnen gut, hochverehrter Freund. Ich empfinde stets mit grösster Freude mit Ihnen die glänzende Genugthuung, dass die grossartige, von Ihnen hervorgerufene naturphilophische Bewegung immer weitere Kreise der Wissenschaft ergreift und immer glänzendere Früchte trägt.

Indem ich Sie freundlichst bitte, meine Perigenesis nachsichtig zu beurtheilen und die Opposition gegen die Pangenesis nur als aufrichtige Frucht des Strebens nach Wahrheit aufzufassen, bleibe ich mit den freundlichsten Grüssen | Ihr treu ergebener | Ernst Haeckel

Footnotes

For a translation of this letter, see Appendix I.
CD’s very lightly annotated copy of Die Perigenesis der Plastidule, oder die Wellenzeugung der Lebenstheilchen (Perigenesis of the plastidule, or the wave generation of vital particles; Haeckel 1876a) is in the Darwin Pamphlet Collection–CUL.
CD had published his ideas on heredity in a chapter titled ‘Provisional hypothesis of pangenesis’ in Variation 2: 357–404. The initial reception of the theory by most naturalists had been lukewarm (see, for example, Correspondence vol. 16, letter to J. D. Hooker, 23 February [1868]). Francis Galton and later George John Romanes tried to devise experiments to test CD’s theory but these proved inconclusive (see Correspondence vols. 17–23 and this volume).
Haeckel 1874 and Haeckel 1868b.
CD had mentioned to Haeckel that he was trying ‘to improve the chaper on Pangenesis’ in the new edition of Variation that he was preparing (Correspondence vol. 23, letter to Ernst Haeckel, 13 November 1875). Haeckel’s name was on CD’s presentation list for Variation 2d ed., which was published in the second half of February 1876 (Publishers’ Circular, 1 March 1876, p. 168), although it carried an 1875 publication date (see Appendix III). The chapter on pangenesis was ‘largely altered and re-modelled’ but the essential principles were unchanged (Variation 2d ed. 1: xiv).
In CD’s copy of Haeckel 1876a, several of the pages are scored in blue pencil by Haeckel. CD’s own annotations were made in pencil. The words in italics in paragraph four of this letter were also underlined in blue pencil by Haeckel.
In Haeckel 1876a, pages 70–2 are scored in blue pencil. Haeckel contrasted CD’s ‘Gemmulae oder Lebenskeimchen’ (gemmules or life-germs) with his own ‘Plastidulen oder Lebensmolekülen’ (plastidules or life molecules) and compared the creation of new plastidules to the growth of a crystal. ‘Plasson’ was Haeckel’s term for undifferentiated protoplasm, the molecules of which were the plastidules. He hypothesised that the character of individual living cells depended on the movements of the plastidules, and compared these movements to wave motions that branched out. Adaptations were ultimately the result of changes in the wave pattern passed on to newly formed plastidules. For a contemporary comparison of Haeckel’s and CD’s theories, see Lankester 1876b.
Monera, a taxon of homogeneous unicellular organisms without nuclei or organelles, was a subsection of Haeckel’s kingdom Protista, which contained microscopic organisms not included in the plant or animal kingdoms (see Haeckel 1866, 1: 135; 2: table I). Haeckel had sent CD his ‘Monographie der Moneren’ (Haeckel 1868a), but the pages of CD’s copy in the Darwin Pamphlet Collection–CUL are uncut (see Correspondence vol. 16, letter from Ernst Haeckel, 22 June 1868).
Part one of the third volume of Histoire naturelle des Iles Canaries (Natural history of the Canary Islands; Webb and Berthelot 1836–50) by Philip Barker Webb and Sabin Berthelot was subtitled ‘contenant la geographie botanique’ (containing botanical geography). It is the only part of the work in the Darwin Library–CUL.
Haeckel visited CD on 21 October 1866 (Emma Darwin’s diary (DAR 242)). He then spent November in Madeira and Tenerife, followed by a three-month stay in Lanzarote from December 1866 (Krauße 1987, pp. 76–7).
The third edition of Anthropogenie oder Entwickelungsgeschichte des Menschen was published in 1877 (Haeckel 1877a).
Haeckel was vice-chancellor of the University of Jena for the summer semester (April to September) of 1876 (Thomas Pester, ‘Die Rektoren/Prorektoren und Präsidenten der Universität Jena 1548/49–2014’, www.uni-jena.de/Universitaetsgeschichte.html, accessed 5 January 2015).

Bibliography

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 27 vols to date. Cambridge: Cambridge University Press. 1985–.

Haeckel, Ernst. 1866. Generelle Morphologie der Organismen. Allgemeine Grundzüge der organischen Formen-Wissenschaft, mechanisch begründet durch die von Charles Darwin reformirte Descendenz-Theorie. 2 vols. Berlin: Georg Reimer.

Krauße, Erika. 1987. Ernst Haeckel. 2d edition. Leipzig: B. G. Teubner.

Variation 2d ed.: The variation of animals and plants under domestication. By Charles Darwin. 2d edition. 2 vols. London: John Murray. 1875.

Variation: The variation of animals and plants under domestication. By Charles Darwin. 2 vols. London: John Murray. 1868.

Translation

From Ernst Haeckel1   9 May 1876

Jena

9 May 1876

Esteemed friend!

Never before have I written to you with such apprehension and diffidence, as today. For in the enclosed essay on “die Perigenesis der Plastidule” I oppose, for the first time (and hopefully for the last!) one of your views.2 Of course, it concerns solely the “provisional hypothesis of pangenesis” from which the theory of descent and your own theory of selection are quite independent.3 But even so it was very difficult for me to oppose your ingenious views in any way, even if only on a single subordinate point.

You may well have noticed that in my writings so far—particularly also in the “Anthropogenie” and “Natürliche Schöpfungsgeschichte”,4 I passed pangenesis over in silence, and to be sure simply because I was from the start unable to warm to it.

As you were lately so kind as to send me the II. edition of your excellent work on “Variation under Domestication” and to direct my attention in particular to the improved description of “pangenesis”, I felt it my duty to clarify my objections to it and my silence about it until now.5

If you would be so kind, some time in a moment of leisure to consider my attempt at a provisional hypothesis of perigenesis, I would ask you to first direct your attention to the passages marked in blue.6 On pag. 70 I have outlined as precisely as possible the difference and contrast between your pangenesis and my perigenesis. The following elements are central to my hypothesis: 1, the mechanical principle of transmitted molecular movement, 2, The active role of the plasson (in the cells, protoplasm + nucleus), 3, The memory or reproductive power of the plastidule (the plasson-molecule, as the sole active living tissue elements).7

I openly acknowledge to you that I am not in a position to reconcile pangenesis with the facts of histology—or to be more precise, with my concept of cell theory and plastid-theory. The latter I have discussed in great detail in my biological studies of Monera and other protists.8 How, according to pangenesis, the gemmules of the entire ancestral line organize themselves in the sperm and in the egg, and how they are supposed to develop an organized structure in the descendant, I am unable to make out; it seems to me to necessarily imply from this an encapsulation of the germs and partial preformation. Forgive me for raising these open and sincere objections!

Besides my heartfelt request for a tolerant reception of “perigenesis”, I have yet a second favour to ask you today, that is for your forgiveness for my returning the enclosed “Geographie botanique” from the “Histoire naturelle des Iles Canaries” by Webb und Berthelot only now.9 You were so kind as to give me this work in October 1866, when I had the pleasure of visiting you at Down, to take along on my trip to the Canaries and it served me well in Teneriffe and Lanzarote.10 After returning I accidentally misplaced it, and only recently found it among a pile of illustrations and sheets of paper in a folder that had been put aside. I beg forgiveness for this disorganisation, and thank you kindly for the loan of the work. Likewise best thanks for the II ed. of “Variation”— At the moment I am busy revising the III. ed. of the “Anthropogenie”, which will be substantially improved. I hope I will be able to send it to you in the course of this year.11 Apart from that I can work on almost nothing, for at Easter I took on the office of vice chancellor of the university of Jena and I am occupied with official business, paperwork and lectures almost all day.12

I hope you are well, esteemed friend. I always feel for you with the greatest joy the splendid satisfaction that the magnificent naturalist movement you inspired is taking hold in ever wider academic circles and is bearing ever more excellent fruit.

While I ask you kindly to judge my perigenesis with forbearance and to view my opposition to pangenesis only as the outcome of the sincere pursuit of truth, I remain with the kindest regards | Your obedient servant | Ernst Haeckel

Footnotes

For a transcription of this letter in its original German, see pp. 159–61.
CD’s very lightly annotated copy of Die Perigenesis der Plastidule, oder die Wellenzeugung der Lebenstheilchen (Perigenesis of the plastidule, or the wave generation of vital particles; Haeckel 1876a) is in the Darwin Pamphlet Collection–CUL.
CD had published his ideas on heredity in a chapter titled ‘Provisional hypothesis of pangenesis’ in Variation 2: 357–404. The initial reception of the theory by most naturalists had been lukewarm (see, for example, Correspondence vol. 16, letter to J. D. Hooker, 23 February [1868]). Francis Galton and later George John Romanes tried to devise experiments to test CD’s theory but these proved inconclusive (see Correspondence vols. 17–23 and this volume).
Haeckel 1874 and Haeckel 1868b.
CD had mentioned to Haeckel that he was trying ‘to improve the chaper on Pangenesis’ in the new edition of Variation that he was preparing (Correspondence vol. 23, letter to Ernst Haeckel, 13 November 1875). Haeckel’s name was on CD’s presentation list for Variation 2d ed., which was published in the second half of February 1876 (Publishers’ Circular, 1 March 1876, p. 168), although it carried an 1875 publication date (see Appendix III). The chapter on pangenesis was ‘largely altered and re-modelled’ but the essential principles were unchanged (Variation 2d ed. 1: xiv).
In CD’s copy of Haeckel 1876a, several of the pages are scored in blue pencil by Haeckel. CD’s own annotations were made in pencil. The words in italics in paragraph four of this letter were also underlined in blue pencil by Haeckel.
In Haeckel 1876a, pages 70–2 are scored in blue pencil. Haeckel contrasted CD’s ‘Gemmulae oder Lebenskeimchen’ (gemmules or life-germs) with his own ‘Plastidulen oder Lebensmolekülen’ (plastidules or life molecules) and compared the creation of new plastidules to the growth of a crystal. ‘Plasson’ was Haeckel’s term for undifferentiated protoplasm, the molecules of which were the plastidules. He hypothesised that the character of individual living cells depended on the movements of the plastidules, and compared these movements to wave motions that branched out. Adaptations were ultimately the result of changes in the wave pattern passed on to newly formed plastidules. For a contemporary comparison of Haeckel’s and CD’s theories, see Lankester 1876b.
Monera, a taxon of homogeneous unicellular organisms without nuclei or organelles, was a subsection of Haeckel’s kingdom Protista, which contained microscopic organisms not included in the plant or animal kingdoms (see Haeckel 1866, 1: 135; 2: table I). Haeckel had sent CD his ‘Monographie der Moneren’ (Haeckel 1868a), but the pages of CD’s copy in the Darwin Pamphlet Collection–CUL are uncut (see Correspondence vol. 16, letter from Ernst Haeckel, 22 June 1868).
Part one of the third volume of Histoire naturelle des Iles Canaries (Natural history of the Canary Islands; Webb and Berthelot 1836–50) by Philip Barker Webb and Sabin Berthelot was subtitled ‘contenant la geographie botanique’ (containing botanical geography). It is the only part of the work in the Darwin Library–CUL.
Haeckel visited CD on 21 October 1866 (Emma Darwin’s diary (DAR 242)). He then spent November in Madeira and Tenerife, followed by a three-month stay in Lanzarote from December 1866 (Krauße 1987, pp. 76–7).
The third edition of Anthropogenie oder Entwickelungsgeschichte des Menschen was published in 1877 (Haeckel 1877a).
Haeckel was vice-chancellor of the University of Jena for the summer semester (April to September) of 1876 (Thomas Pester, ‘Die Rektoren/Prorektoren und Präsidenten der Universität Jena 1548/49–2014’, www.uni-jena.de/Universitaetsgeschichte.html, accessed 5 January 2015).

Bibliography

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 27 vols to date. Cambridge: Cambridge University Press. 1985–.

Haeckel, Ernst. 1866. Generelle Morphologie der Organismen. Allgemeine Grundzüge der organischen Formen-Wissenschaft, mechanisch begründet durch die von Charles Darwin reformirte Descendenz-Theorie. 2 vols. Berlin: Georg Reimer.

Krauße, Erika. 1987. Ernst Haeckel. 2d edition. Leipzig: B. G. Teubner.

Variation 2d ed.: The variation of animals and plants under domestication. By Charles Darwin. 2d edition. 2 vols. London: John Murray. 1875.

Variation: The variation of animals and plants under domestication. By Charles Darwin. 2 vols. London: John Murray. 1868.

Summary

Sends Die Perigenesis der Plastidule [1876]. Comments on CD’s theory of Pangenesis. Explains his own theory of Perigenesis.

Returns Webb and Berthelot, Îles Canaries; Géographie botanique [1840].

Describes work on 3d ed. of Anthropogenie.

Letter details

Letter no.
DCP-LETT-10501
From
Ernst Philipp August (Ernst) Haeckel
To
Charles Robert Darwin
Sent from
Jena
Source of text
DAR 166: 68
Physical description
7pp (German) †

Please cite as

Darwin Correspondence Project, “Letter no. 10501,” accessed on 30 May 2020, https://www.darwinproject.ac.uk/letter/DCP-LETT-10501.xml

Also published in The Correspondence of Charles Darwin, vol. 24

letter