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Darwin Correspondence Project

From Henry Holland   2 January 1865

Brook Street.

Jany. 2d. | 1865

My dear Charles,

First, let this note convey to yourself, & to all your family, my earnest good wishes for the year just begun, & for all & many years succeeding it.1 Receive these wishes as equally cordial & sincere; but do not occupy your time in answering them. I shall understand the reciprocity of kind feeling, without troubling you to write it.

Next, let me thank you for the paper on the 3 forms of the Lythrum Salicaria & their sexual relations2—a most curious research; & showing further (if further proof were needful) that it is to the primal mystery of Generation that we must look for explanation of the phenomena of Life, & the succession of Life on the Earth.— It is hard to say how far we can ever get into this mystery; but your researches run in the right road.—3

I despair of being ever told, in the shape of a physical law, why the nose of the Grandson is a copy of the Grandfathers, with another configuration of nose between.

You have probably seen Cobbold’s curious statement (in his book on Entozoa) of the 4 successive stages of development, & successive habitats, of the tape-worm species4

The allusion to these things carries me back in memory, to your capital monograph on the Cirripeds, & their parasitic & bi-sexual peculiarities.5

I write hastily, but ever, my dear Charles, your’s affy | H Holland

P.S. | I gladly see that you are inducting your Son into your researches6

The D. of Argyll sent me a few days ago his Address as President of the R Society of Edinburgh—chiefly occupied with the question of Origin of Species7


Holland occasionally served as a physician to CD, and had been consulted on the illnesses of CD’s children, Henrietta and Horace (see, for example, Correspondence vol. 8, letter to J. D. Hooker, 5 June [1860], and Correspondence vol. 10, letter from Henry Holland, 26 March [1862]).
‘Three forms of Lythrum salicaria’. Holland’s name appears on CD’s presentation list for the paper (see Correspondence vol. 12, Appendix III).
Holland had reviewed scientific works for the Edinburgh and Quarterly Reviews for many years. He revised his 1859 article ‘Life and organisation’ to include a commentary on Origin (see Holland 1859 and Holland 1862, pp. 98–9). CD was highly critical of Holland’s reviews (see, for example, Correspondence vol. 4, letter to J. D. Hooker, [18 April 1847], and Correspondence vol. 11, letter to J. D. Hooker, 23 [June 1863]). In the letter to Charles Lyell, 25 October [1859] (Correspondence vol. 7), CD expressed his hope that Holland would not be chosen to review Origin for the Quarterly Review, although he later noted that Holland went an ‘immense way’ with CD and his supporters (Correspondence vol. 7, letter to Charles Lyell, [10 December 1859]). For Holland’s views on Origin, see also Correspondence vol. 7, letter from Henry Holland, 10 December [1859].
Holland refers to the discussion of the development of the common tapeworm (Taenia solium) by Thomas Spencer Cobbold in his monograph on internal parasites (Cobbold 1864, pp. 220–2). Cobbold described the life-cycle of the tapeworm as it migrated from its parent colony in the bowel of the host, through drains and ditches, until it was ingested first by pigs, and then, in the form of ‘measly pork’, by humans. A review of Cobbold 1864 had appeared in the 26 November 1864 issue of the Reader, pp. 668–70; CD was a regular subscriber to the journal (see letter from J. D. Hooker, 1 January 1864 and n. 14).
The reference is to CD’s work on ‘complemental males’ in barnacles. In several species of Cirripedia, CD had observed minute males attached to the bodies of hermaphrodites, and differing greatly from them in size and structure (see Living Cirripedia (1851), pp. 231–2 and 281–93, Living Cirripedia (1854), pp. 23–30, and Newman 1993, pp. 377–81). In his letter to J. D. Hooker, 10 May 1848 (Correspondence vol. 4), CD remarked that the discovery was suggestive of the development of separate sexes, and thus of significance for his theory of species (see also Correspondence vol. 4, Appendix II, pp. 399–400). CD later suggested that complemental males may have developed in Cirripedes to enable intercrossing between two hermaphrodites (see ‘On the males and complemental males of certain cirripedes, and on rudimentary structures’, Nature 8 (1873): 431–2; Collected papers 2: 177–82).
In ‘Three forms of Lythrum salicaria’, pp. 172, 174, CD referred to observations and camera-lucida drawings made by his son William (see Collected papers 2: 108–9, 110; for William’s work with Lythrum, see Correspondence vols. 10 and 11). William also made extensive observations for CD on dimorphism in Pulmonaria and other genera in 1862, 1863, and 1864 (see Correspondence vols. 10–12).
The reference is to the opening address delivered to the Royal Society of Edinburgh by its president, George Douglas Campbell, eighth duke of Argyll (G. D. Campbell 1864). See letter from Charles Lyell, 16 January 1865.


Thanks for Lythrum paper [Collected papers 2: 106–31].

T. S. Cobbold’s book on the Entozoa [1864].

Remarks on development of the tapeworm.

Letter details

Letter no.
Holland, Henry
Darwin, C. R.
Sent from
London, Brook St
Source of text
DAR 166: 245
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 4735,” accessed on 17 January 2017,