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Darwin Correspondence Project

From Ernst Haeckel1   10 December 1872

Jena

10 Decbr 72

Mein theurer hochverehrter Freund!

Verzeihen Sie, dass ich Ihnen erst heute für das gütigst übersandte Explr. Ihres sehr interessanten Werkes über “Expression of the emotions etc” meinen freundlichsten Dank sage.2 Ich war aber in den letzten Monaten völlig absorbirt von der Vollendung meiner “Monographie der Kalkschwämme” (Calcispongien oder Grantien).3 Um das Werk fertig zu machen noch in diesem Jahr, musste ich Tag und Nacht schreiben, und in den letzten Wochen täglich einen ganzen Druckbogen corrigiren. Eine schreckliche Arbeit, welche mich zu keiner Lectüre kommen liess. Ich habe daher Ihr Buch on “Expression” etc. nur erst flüchtig durchlesen können und hoffe jetzt, nach meiner Befreiung von den Spongien, es in ganzer Musse lesen zu können.

Meine Monographie der Kalk-Spongien (2 Bände Text und 1 Atlas mit 60 Tafeln) werden Sie in den nächsten Wochen direct von meinem Verleger erhalten, welchen ich beauftragt habe, Ihnen ein Exemplar zu schicken.4 Vorläufig sende ich Ihnen beifolgend die beiden letzten Bogen des ersten Bandes und das Titel-Blatt mit Vorrede.5 Ich hoffe, dass die generellen Resultate im 7 und 8 Capitel Sie interessiren werden, besonders das “biogenetische Grundgesetz, die generischen und spezifischen, connexiven und transitorischen Varietäten, und die “Ursachen der Formbildung” (p. 479, 481).6 In dem III Capitel (Morphologie) wird das Intercanal-System für Sie von Interesse sein (p. 275–290), im IV. Capitel die Parallele zwischen Ontogenie und Phylogenie des Olynthus (p. 347), im V. Capitel die Anpassung (p. 381–391), die sich hier ausgezeichnet verfolgen lässt, und die Vererbung (p. 399).7 Das Resultat für die generelle Zoologie ist insofern wichtig, als der Species-Begriff in gewöhnlichem Sinne bei den Spongien gar nicht zu fassen ist; die Variabilität übersteigt alle Grenzen. Ich musste daher im speciellen Theile (im II. Bande) 2 Systeme machen, ein natürliches und ein künstliches.8 Zur Vergleichung beider bitte ich Sie, die Formen von Ascetta primordialis auf Taf. 2 anzusehen, ferner Ascaltis Darwinii (Taf. 10, Fig. 3) mit ihren generischen und specifischen Varietäten (A. Erasmi und A. Caroli), ferner Leucetta primiginenia (Taf. 21) und Sycandra compressa (Taf. 57).9 Die Polymorphose dieser und anderer Arten ist für die Descendenz-Theorie höchst lehrreich

Von besonderer Wichtigkeit scheint mir der Olynthus zu sein, die einfachste Form der Kalkschwämme, weil dieser sich unmittelbar aus der Gastrula ableiten lässt, die als Larve oder Embryonal-Form auch bei den höheren Thierstämmen vorkommt. (p. 466, 467). Ich glaube, dass dadurch der Stammbaum des Thierreichs auf S. 465, und besonders die Descendenz aller Thiere (exclus. Protozoen) von der Gastraea an Sicherheit ausserordentlich gewinnt. Die beiden Lamellen, aus denen die Magenwand des Olynthus besteht, sind identisch mit den beiden Keimblättern der höheren Thiere. Die primordiale Phylogenie der höheren Thiere wird da〈d〉ur〈ch〉 ausserordentlich klar; zumal dieselbe Gastrula auch bei Amphioxus und den Ascidien sich findet.10

Die Bedeutung der Calcispongien scheint mir vorzüglich darin zu gipfeln, dass sie einerseit eng an die Polypen (Hydra, Cordylophora) sich anschliessen, anderseits viel einfacher als die übrigen Spongien in dem Ascon-Typus sich offenbaren. Die Homologie des Olynthus und der Hydra erscheint mir unzweifelhaft, und somit auch der morphologische Werth ihrer inneren Höhle als Darmhöhle11   Durch die Gastrula entfernen sie sich zugleich weit von den Protozoen.12 Wenn Sie die Gastrula der Calcispongien (Atlas Taf. 13, Taf. 30, Taf. 44) vergleichen mit der entsprechenden Larvenform der Würmer und Echinodermen, der Ascidien und des Amphioxus (wie ich sie z. B. auf Taf. X, Fig. A4, B4 in meiner “natürlichen Schöpfungsgeschichte13 abgebildet habe) so werden Sie die morphologische Identität zugestehen müssen.

Ich sende Ihnen noch ein zweites Exemplar der beiden letzten Capitel, mit der Bitte, es an Sir John Lubbock gelangen zu lassen, dessen Adresse ich nicht kenne. Wenn Sie Sir Lubbock sprechen sollten, bitte ich ihm zu sagen, dass seine “Prehistoric Times jetzt in das Deutsche übersetzt werden. Ich habe Virchow gebeten, eine Vorrede dazu zu schreiben.14

Haben Sie die englische Übersetzung meiner Schöpfungsgeschichte schon erhalten? Oder ist sie noch nicht fertig?15

Ich hoffe, mein theurer Freund, dass Sie mit Ihrer Gesundheit zufrieden sind!

Indem ich meinen Dank für Übersendung Ihres Buchs wiederhole, bleibe ich mit der bekannten Verehrung Ihr von ganzem Herzen | ergebener | Ernst Haeckel

[DIAG HERE]

Grosses Aufsehen in Germany erregt jetzt ein Buch unseres geistvollen Theologen David Strauss: “Alter und neuer Glaube”. Der Verfasser des “Lebens Jesu” zeigt sich hier als überzeugter Darwinist, und entwickelt eine philosophische Religion auf dem Boden des Darwinismus!!16

Es geht vorwärts!!

Footnotes

For a translation of this letter, see Correspondence vol. 20, Appendix I.
Haeckel’s name is on CD’s presentation list for Expression (see Correspondence vol. 20, Appendix V).
Haeckel refers to his monograph on calcareous sponges (Haeckel 1872a).
CD’s annotated copy of Haeckel 1872a is in the Darwin Library–CUL (see Marginalia 1: 357–8). Haeckel’s publisher was Georg Ernst Reimer.
The enclosure has not been found.
For the section on the biogenetic law (ontogeny is the rapid recapitulation of phylogeny), see Haeckel 1872a 1: 471–3; on the generic and specific, connective and transitory varieties, see ibid., pp. 479–80; on causes of structure, see ibid., pp. 481–3.
Chapter 3 of Haeckel 1872a contains a section (2A) on the canal-system with a subsection on the intercanal or intervascular system (Haeckel 1872a 1: 275–92). Haeckel included a table linking stages in the ontogeny of Olynthus (now Leucosolenia) with phylogenetic stages (ibid., p. 347; see also Di Gregorio 2005, pp. 208–11).
For Haeckel’s description of the classificatory systems and the criteria used for each system, see Haeckel 1872a 1: 79–83.
The tables Haeckel refers to are in the Atlas to Haeckel 1872a. The species names are part of his ‘natural’ system of classification. Ascetta primordialis is now Clathrina primordialis; Ascaltis darwinii and the varieties A. erasmi and A. caroli are now Clathrina darwini.
Haeckel equated specific ontogenetic stages such as the gastrula (the first invagination of the ball of embryonic cells) with corresponding hypothetical ancestral organisms (in this case, Gastraea). Amphioxus (the lancelet; now Branchiostoma lanceolatum) was initially classed as a primitive fish (subclass Acranii) but has now been moved to its own class, Cephalochordata. Ascidiacea is a class in the subphylum Tunicata. Both are in the phylum Chordata.
Hydra is a genus of the family Hydridae; Cordylophora is in the family Cordylophoridae. Both now belong to the order Anthoathecata within the class Hydrozoa. The Ascones was the most primitive family in Haeckel’s ‘natural’ system of classification and Olynthus was the most primitive genus within the ‘artificial’ system (Haeckel 1872a 1: 482).
In Haeckel’s classificatory system, sponges were first placed in the kingdom Protista along with single-celled Protozoa (see Haeckel 1866, 2: Table I). Haeckel later reassigned sponges to his kingdom Animalia and further developed his ‘Gastraea theory’, which held that the ancestral mode of gastrulation in all animals was by invagination to produce a functional gut (Haeckel 1872a).
Haeckel had sent CD the third edition of his Natürliche Schöpfungsgeschichte (Natural history of creation; Haeckel 1872b) earlier in the year (see letter to Ernst Haeckel, 2 September 1872). For the table and description of the figures, see Haeckel 1872b, facing p. 486 and p. 671.
The German translation of Lubbock’s Prehistoric times (Lubbock 1865) appeared in 1874 and had an introduction by Rudolf Virchow (Lubbock 1874).
The first English translation of Haeckel’s Natürliche Schöpfungsgeschichte was published in 1876 (Haeckel 1876a). The translation was revised by Edwin Ray Lankester from an original translation made by ‘a young lady’ (Haeckel 1876a, 1: note facing p. 1).
David Friedrich Strauss’s ‘new faith’ (neue Glaube) was based on natural science, particularly on evolution and CD’s theory of human evolution (see Strauss 1872, pp. 174–97). For more on the reception of the book, see Weikart 1993, pp. 483–4. Haeckel also refers to Strauss 1836 (Das Leben Jesu).

Translation

From Ernst Haeckel1   10 December 1872

Jena

10 Decbr 72

My dear most honoured friend!

Forgive me for only today expressing my kindest thanks for the copy of your very interesting work on “Expression of the emotions etc”, which you so obligingly sent me.2 Over the past months, I was completely absorbed by the task of completing my “Monographie der Kalkschwämme” (Calcispongiae or Grantia).3 In order to complete the work in this year, I had to write day and night, and in the last weeks I had to correct an entire set of proofs daily. An awful labour, which prevented me from doing any reading at all. This is why I was able only to skim through your book on “Expression”, and now, liberated from the Spongiae, I hope to be able to read it at leisure.

You will receive my monograph on the calcareous sponges (2 volumes text and 1 atlas with 60 plates) within the next few weeks, directly from my publisher, whom I have instructed to send you a copy.4 For the time being I am sending you the last two chapters of the first volume and the title page of the preface.5 I hope that you will be interested in the general conclusions of ch. 7 and 8, in particular “biogenetische Grundgesetz, die generischen und spezifischen, connexiven und transitorischen Varietäten, and the “Ursachen der Formbildung”(p. 479, 481).6 Of interest to you in chapter III (morphology) is the intercanal-system (p. 275–290), in chapter IV. the parallel between ontogeny and phylogeny of the Olynthus (p. 347), in chapter V. adaptation (p. 381–391), which can be followed here most admirably, and heredity (p. 399).7 The result for general zoology is important insofar as the concept of species in the usual sense is not at all applicable to sponges; their variability exceeds all limits. Thus, in the special part (in volume II), I had to create 2 systems, a natural and an artificial one.8 For a comparison between the two I ask you to inspect the forms of Ascetta primordialis in table 2, also Ascaltis Darwinii (table 10, fig. 3) with their generic and specific varieties (A. Erasmi and A. Caroli), and furthermore Leucetta primiginenia (tab. 21) and Sycandra compressa (tab. 57).9 The polymorphosis of this and of other kinds is most instructive for the theory of descent.

Olynthus seems to me to be of particular importance, the simplest from of calcareous sponge, because it can be traced back directly to the Gastrula, which also occurs as the larval or embryonic form of higher animals. (p. 466, 467). I believe that through this, the phylogenetic tree of the animal kingdom on p. 465, and especially the descent of all animals (excepting Protozoa) from the Gastraea gain tremendously in certainty. The two lamellae that form the stomach wall of the Olynthus are indentical with the two germ layers of higher animals. With this, the primordial phylogeny of higher animals becomes extremely clear; for the same gastrula can be found in Amphioxus and in the Ascidians.10

To my mind, the significance of the Calcispongiae seems to culminate chiefly in that on the one hand they are closely related to Polyps (Hydra, Cordylophora), and that on the other hand they are evidently far more simple than the lowest sponges of the Ascon-type. The homology of Olynthus and Hydra seems to me indubitable, and consequently the morphological significance of their inner cavity is that of an intestinal cavity11   Also, because of the Gastrula, the Spongi are far removed from the Protozoa.12 If you compare the Gastrula of the Calcispongi (atlas table 13, table 30, table 44) with the corresponding larval form of worms and echinoderms, of Ascidians and of Amphioxus (as I have reproduced them e.g. on table X. fig. A4, B4 in my “natürliche Schöpfungsgeschichte),13 you must concede their morphological identity.

I am sending you yet another copy of the two last chapters, with the request that you may arrange for the same to get to Sir John Lubbock, whose address I do not have. Should you talk to Sir Lubbock, please tell him that his “prehistoric times are now being translated into German. I asked Virchow to write an introduction.14

Have you already received the English translation of my Schöpfungsgeschichte? Or is it not ready yet?15

My dear friend, I hope you are content with your health!

Thanking you again for sending me your book, I remain with the usual respect your | wholeheartedly devoted | Ernst Haeckel

[DIAG HERE]

A great sensation in Germany is now being created by a book by our brilliant theologian David Strauss: “Alte und neue Glaube”. The author of “Leben Jesu” reveals himself here as a convinced Darwinist, and develops a philosophical religion on the basis of Darwinism!!16

We are making progress!!

Footnotes

For a transcription of this letter in its original German, see pp. 561–5.
Haeckel’s name is on CD’s presentation list for Expression (see Correspondence vol. 20, Appendix V).
Haeckel refers to his monograph on calcareous sponges (Haeckel 1872a).
CD’s annotated copy of Haeckel 1872a is in the Darwin Library–CUL (see Marginalia 1: 357–8). Haeckel’s publisher was Georg Ernst Reimer.
The enclosure has not been found.
For the section on the biogenetic law (ontogeny is the rapid recapitulation of phylogeny), see Haeckel 1872a 1: 471–3; on the generic and specific, connective and transitory varieties, see ibid., pp. 479–80; on causes of structure, see ibid., pp. 481–3.
Chapter 3 of Haeckel 1872a contains a section (2A) on the canal-system with a subsection on the intercanal or intervascular system (Haeckel 1872a 1: 275–92). Haeckel included a table linking stages in the ontogeny of Olynthus (now Leucosolenia) with phylogenetic stages (ibid., p. 347; see also Di Gregorio 2005, pp. 208–11).
For Haeckel’s description of the classificatory systems and the criteria used for each system, see Haeckel 1872a 1: 79–83.
The tables Haeckel refers to are in the Atlas to Haeckel 1872a. The species names are part of his ‘natural’ system of classification. Ascetta primordialis is now Clathrina primordialis; Ascaltis darwinii and the varieties A. erasmi and A. caroli are now Clathrina darwini.
Haeckel equated specific ontogenetic stages such as the gastrula (the first invagination of the ball of embryonic cells) with corresponding hypothetical ancestral organisms (in this case, Gastraea). Amphioxus (the lancelet; now Branchiostoma lanceolatum) was initially classed as a primitive fish (subclass Acranii) but has now been moved to its own class, Cephalochordata. Ascidiacea is a class in the subphylum Tunicata. Both are in the phylum Chordata.
Hydra is a genus of the family Hydridae; Cordylophora is in the family Cordylophoridae. Both now belong to the order Anthoathecata within the class Hydrozoa. The Ascones was the most primitive family in Haeckel’s ‘natural’ system of classification and Olynthus was the most primitive genus within the ‘artificial’ system (Haeckel 1872a 1: 482).
In Haeckel’s classificatory system, sponges were first placed in the kingdom Protista along with single-celled Protozoa (see Haeckel 1866, 2: Table I). Haeckel later reassigned sponges to his kingdom Animalia and further developed his ‘Gastraea theory’, which held that the ancestral mode of gastrulation in all animals was by invagination to produce a functional gut (Haeckel 1872a).
Haeckel had sent CD the third edition of his Natürliche Schöpfungsgeschichte (Natural history of creation; Haeckel 1872b) earlier in the year (see letter to Ernst Haeckel, 2 September 1872). For the table and description of the figures, see Haeckel 1872b, facing p. 486 and p. 671.
The German translation of Lubbock’s Prehistoric times (Lubbock 1865) appeared in 1874 and had an introduction by Rudolf Virchow (Lubbock 1874).
The first English translation of Haeckel’s Natürliche Schöpfungsgeschichte was published in 1876 (Haeckel 1876a). The translation was revised by Edwin Ray Lankester from an original translation made by ‘a young lady’ (Haeckel 1876a, 1: note facing p. 1).
David Friedrich Strauss’s ‘new faith’ (neue Glaube) was based on natural science, particularly on evolution and CD’s theory of human evolution (see Strauss 1872, pp. 174–97). For more on the reception of the book, see Weikart 1993, pp. 483–4. Haeckel also refers to Strauss 1836 (Das Leben Jesu).

Summary

Thanks CD for Expression.

Describes work on Die Kalkschwämme and its principal conclusions.

The application of biogenetic law.

Notes variability among calcareous sponges.

Gastrula-like "Gastraea" as ancestor of multicellular animals.

Posits homology between Hydra, Olynthus of calcareous sponges, and initial germ layers of higher animals.

Comments on Lubbock’s Prehistoric times [1865]

and on David Strauss’s Der alte und der neue Glaube [1872].

Letter details

Letter no.
DCP-LETT-8669
From
Ernst Philipp August (Ernst) Haeckel
To
Charles Robert Darwin
Sent from
Jena
Source of text
DAR 166: 34, 59
Physical description
8pp (German)

Please cite as

Darwin Correspondence Project, “Letter no. 8669,” accessed on 19 November 2017, http://www.darwinproject.ac.uk/DCP-LETT-8669

Also published in The Correspondence of Charles Darwin, vol. 20

letter