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Darwin Correspondence Project

From Anton Dohrn   31 May 1875

Naples. Palazzo Torlonia.

31. May. 75.

Dear Mr. Darwin!

Many thanks for Your kind letter.1

I am very open to see my little pamphlet abused, and therefore very thankful if it meets at least some interest.2 I am quite aware of its revolutionary character,—but I am equally convinced of its truth.

To expect that authorities will soon acknowledge the whole or even a part of the speculations would be very wrong on my part. Gegenbaur and Haeckel for instance have always followed the very opposite doctrine, and even in his last publication, in the introduction to his new Periodical “Morphologisches Jahrbuch” Gegenbaur abuses very much the view I propose, and calls it the very extract of uncritical and unscientific method and view.3 We have been quarrelling on that chapter for many years,— and his opposition cannot teach anything new to me. To call opponents ignorant, uncritical, unscientific is a matter of taste rather, than a serious refutation; should Prof. Haeckel wish to come down upon me, I am prepared to read quite other things, to be more or less declared a lunatic. All this may be a great satisfaction to its author’s but can hardly increase the authority of their position, and I am very satisfied, that already among the younger Zoologists there is a strong disposition to accept my views.4 All I could possibly expect by the publication of my pamphlet was to put a stop to the dogmatical treatment of the Amphioxus-Ascidian affair, and to open new roads for speculation and investigation on the sides of the Annelid-homology. I think, this has already been achieved, and I am now busy to take up a special question and work it into a more complete form.

I regret to have added the exposition of my belief into a general degeneration throughout the whole organic world. But even that meets here and there with a partial approval, and will have some influence on the treatment of morphological investigation. I myself believe it very much.5

I am very sorry to read that the Anderson-School is not doing well. I know how expensive these institutions are, when fully at work, but the Americans ought to keep it up.6 The Zool. Station is flourishing and would be much more so, had not the bad financial state of Germany and everywhere put a restriction on the generosity of rich people. I hope nevertheless to carry it more and more to perfection.7

Hoping that Your health has not disappointed You to much in these last times and wishing for its improving I add my kindest regards to Mrs. Darwin and Your sons and to Yourself and remain, dear Mr. Darwin | Your | sincerely devoted | Anton Dohrn


CD had commented on Dohrn’s monograph on the origin of vertebrates (Dohrn 1875) and had cautioned Dohrn not to try to extend the degradation principle (see letter to Anton Dohrn, 24 May 1875 and n. 2).
Dohrn was a proponent of the annelid theory of vertebrate origins; Carl Gegenbaur and Ernst Haeckel were supporters of the rival ascidian theory (see letter to Anton Dohrn, 24 May 1875 and n. 2). In the opening essay to his new journal Morphologisches Jahrbuch, Gegenbaur defined the scope and methodology of the science of morphology (Gegenbaur 1875). Although he did not refer to Dohrn by name, he criticised as unscientific the central anatomical comparison on which Dohrn’s annelid theory was based (ibid., pp. 6–7).
Another major supporter of an annelid theory at this time was Carl Gottfried Semper (see letter from Anton Dohrn, 7 February 1875 and n. 7).
Dohrn had attempted to account for similarities between ascidians and vertebrates by proposing that ascidians were degenerate rather than ancestral forms; he also considered cyclostomes (jawless fish) and Amphioxus (now Branchiostoma lanceolatum, the lancelet) to be degenerate, and associated degeneration with a change of function (Functionswechsel), often linked with parasitism (see Dohrn 1875, pp. 32–60).
The John Anderson School of Natural History on Penikese Island, Massachusetts, was established by Louis Agassiz in 1873 (Marcou 1896, 2: 201–7). It was set up as a summer school for teachers rather than as a research institution along the lines of Dohrn’s Zoological Station in Naples (see Winsor 1991, p. 170).
For more on the funding of the Zoological Station in Naples, see the letter from Anton Dohrn, 7 February 1875 and nn. 2 and 3. The over-expansion of the German economy following unification led to a crash in 1873 that was part of a worldwide economic recession (see Wehler 1985, p. 33).


Dohrn, Anton. 1875. Der Ursprung der Wirbelthiere und das Princip des Functionswechsels. Genealogische Skizzen. Leipzig: Wilhelm Engelmann. [Reprinted in Theory in Biosciences 125 (2007): 181–241.]

Gegenbaur, Carl. 1875. Die Stellung und Bedeutung der Morphologie. Morphologisches Jahrbuch 1 (1875–6): 1–19.

Marcou, Jules. 1896. Life, letters, and works of Louis Agassiz. 2 vols. London and New York: Macmillan and Co.

Wehler, Hans-Ulrich. 1985. The German Empire, 1871–1918. Leamington Spa and Dover, N.H.: Berg Publishers.

Winsor, Mary Pickard. 1991. Reading the shape of nature. Comparative zoology at the Agassiz museum. Chicago and London: University of Chicago Press.


AD is aware of revolutionary character of his pamphlet [Ursprung der Wirbelthiere]. Authorities will not agree with him. Carl Gegenbaur and Ernst Haeckel are opposed. Younger biologists are disposed to accept his views. All he can expect is to put a stop to "the Amphioxus–Ascidian affair, and to open a road for speculation and for investigation on the side of the Annelid-homology".

Letter details

Letter no.
Felix Anton (Anton) Dohrn
Charles Robert Darwin
Sent from
Source of text
DAR 162: 216
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 10003,” accessed on 8 March 2021,

Also published in The Correspondence of Charles Darwin, vol. 23