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Darwin Correspondence Project

To T. H. Huxley   22 December [1866]1

Down. | Bromley. | Kent. S.E.

Dec. 22d

My dear Huxley

I suppose that you have received Häckels book some time ago, as I have done.2 Whenever you have had time to read through some of it, enough to judge by, I shall be very curious to hear your judgment.— I have been able to read a page or two here & there, & have been interested & instructed by parts. But my vague impression is that too much space is given to methodical details, & I can find hardly any facts or detailed new views. The number of new words, to a man like myself weak in his Greek, is something dreadful. He seems to have a passion for defining, I daresay very well, & for coining new words.3 From my very vague notions on the book & from its immense size, I shd. fear a Translation was out of the question. I see he often quotes both of us with praise.—

I am sure I shd. like the book much, if I could read it straight off instead of groaning & swearing at each sentence.

I have not yet had time to read your Phys. book except one chapter; but I have just reread your book on “Man’s Place &c”, & I think I admire it more this second time even than the first.4 I doubt whether you will ever have time, but if ever you have, do read the Chapt. on Hybridism in new Edit. of Origin,5 for I am very anxious to make you think less seriously on that difficulty.— I have improved the Chapt. a good deal I think, & have come to more definite views— Asa Gray & Fritz Müller (the latter especially) think that the new facts on illegitimate offspring of dimorphic plants throw much indirect light on the subject.—6 Now that I have worked up Domestic Animals I am convinced of the truth of the Pallasian view of loss of sterility under Domestication & this seems to me to explain much.—7

But I had no vile intention, when I began this note, of running on at such length on Hybridism, but you have been Objector-General on this head.—8

Ever my dear Huxley | Your sincere friend | Ch. Darwin


The year is established by the reference to Ernst Haeckel’s Generelle Morphologie (see n. 2, below).
Haeckel had arranged in October 1866 to have a copy of his book, Generelle Morphologie (Haeckel 1866), sent to CD (see letter from Ernst Haeckel, 19 October 1866 and n. 3).
Among the neologisms in Haeckel’s book are ‘ontogeny’ (Ontogenie), ‘phylogeny’ (Phylogenie), and ‘ecology’ (Œcologie; see Haeckel 1866, 1: 53, 57 and 2: 286). On Haeckel’s coining of new words, see S. J. Gould 1977, p. 76.
CD refers to Lessons in elementary physiology (T. H. Huxley 1866) and Evidence as to man’s place in nature (T. H. Huxley 1863a). CD’s annotated copy of T. H. Huxley 1863a is in the Darwin Library–CUL (see Marginalia 1: 424). For CD’s original criticism, see Correspondence vol. 11, letter to T. H. Huxley, 26 [February 1863].
See Origin 4th ed., pp. 292–338.
Huxley had frequently maintained that natural selection could not be fully accepted as a mechanism of the origin of species until a new species created by means of artificial selection had been produced (see, for example, T. H. Huxley 1863b, pp. 147–9). His position was based on the widely accepted view that sterility of hybrids was an essential criterion of species. Huxley’s critique served as an important impetus to CD’s investigations into cross and hybrid sterility. For a summary of CD’s and Huxley’s earlier discussions on the topic, and some of CD’s unpublished notes on hybridity, see Correspondence vol. 10, Appendix VI. In Origin 4th ed., p. 323, CD remarked that ‘the physiological test of lessened fertility, both in first crosses and in hybrids, is no safe criterion of specific distinction’. Asa Gray had recently written that the resemblance of dimorphic crosses to hybrid crosses was a ‘Very interesting & capital point’ in favour of CD (see letter from Asa Gray, 10 October 1866 and n. 7). Müller had been collecting information on dimorphic and trimorphic plants since CD had asked him to observe whether Brazilian varieties of Oxalis exhibited different forms (letter to Fritz Müller, 23 May 1866; see letters from Fritz Müller, 2 August 1866, 1 and 3 October 1866, and [2 November 1866]).
The reference is to Pyotr Simon Pallas and his view that under a long period of domestication the tendency to sterility in crosses was eliminated (see Pallas 1780 and Origin, pp. 253–4). CD’s notes on this work are in DAR 196.5; see also Correspondence vol. 8 for more on CD’s view of Pallas.
See n. 6, above.


Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.

Gould, Stephen Jay. 1977. Ontogeny and phylogeny. Cambridge, Mass.; London: Belknap Press of Harvard University Press.

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.

Marginalia: Charles Darwin’s marginalia. Edited by Mario A. Di Gregorio with the assistance of Nicholas W. Gill. Vol. 1. New York and London: Garland Publishing. 1990.

Origin 4th ed.: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. 4th edition, with additions and corrections. By Charles Darwin. London: John Murray. 1866.

Origin: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. By Charles Darwin. London: John Murray. 1859.

Pallas, Pyotr Simon. 1780. Mémoire sur la variation des animaux; première partie. Acta Academiæ Scientiarum Imperialis Petropolitanæ (1780 pt 2): 69–102.


First impressions of Haeckel’s Generelle morphologie.

Has received THH’s [Lessons in elementary] Physiology [1866]

and reread Man’s place.

Asks THH to read revised "Hybridism" chapter in new edition of Origin. Hopes it will change THH’s view.

Convinced of P. S. Pallas’ view of loss of sterility under domestication.

Letter details

Letter no.
Charles Robert Darwin
Thomas Henry Huxley
Sent from
Source of text
Imperial College of Science, Technology, and Medicine Archives (Huxley 5: 196)
Physical description
ALS 7pp

Please cite as

Darwin Correspondence Project, “Letter no. 5315,” accessed on 15 April 2024,

Also published in The Correspondence of Charles Darwin, vol. 14