Confirms CGBD's impression given in a letter to J. S. Henslow that CD in the Origin did not touch directly upon the final causes of sexuality, which CD considers one of the "profoundest mysteries in nature". CD is inclined to stress sexuality as the means of keeping forms constant and checking variation although he grants its role in the origination of varieties. [See 2869.]
Hartfield | Tonbridge Wells
My dear D
Henslow has sent me part of a note of yours & his answer.— You are quite right that there is nothing direct in my Book on the final cause or manner of origination of the sexes. It seems to me one of the profoundest mysteries in nature. Especially since the facts of parthenogenesis have been clearly made out. I have heard Huxley remark that the old saying was ``it was a wise child who knew who his Father was'', but now the saying might be, ``it was a wise child who knew whether he had a Father.''—
I have often speculated on your view, & I have somewhere got a case of a trifling variation being propagated by gemmation with anim<als> (in a coral) just as we see almost every shade of difference propagated by grafts & buds with plants.
I daresay that you are quite right that one of the final causes of sexuality is the
origination of varieties; but the number of cases which can
be collected of ``sporting'' plants ie plants which have varied by gemmation has made me
rather doubtful on this head.— I am inclined to
lay more stress on sexuality (p. 103 Origin of
Pray believe me | My dear D
- f1 2869a.f1The year is established by the date on which Daubeny read his paper in Oxford (see n. 3, below) and from CD's letter to J. S. Henslow, 16 July  (Correspondence vol. 8), which refers to CD's sending the present letter.
- f2 2869a.f2From 10 July to 2 August, CD joined Emma and Henrietta Darwin at The Ridge, Hartfield, East Sussex, the home of Emma's sister, Sarah Elizabeth Wedgwood (see Correspondence vol. 8, including Appendix II).
- f3 2869a.f3Daubeny's note and John Stevens Henslow's answer have not been found; however, see the letter to J. S. Henslow, 16 July  (Correspondence vol. 8). The correspondence between Daubeny and Henslow was evidently prompted by a paper read by Daubeny at the meeting of the British Association for the Advancement of Science in Oxford, in a session chaired by Henslow on 28 June 1860 (see Athenæum, 7 July 1860, p. 25). CD did not attend the meeting (see Correspondence vol. 8, letter to J. D. Hooker, 26 [June 1860]). In writing the present letter to Daubeny, CD probably relied on information from Henslow on the content of Daubeny's paper, as he did not receive the published text (Daubeny 1860a) until later (see this volume, Supplement, letter to Charles Daubeny, 1 August  and n. 2). CD may also have read a report of Daubeny's paper in the press (see, for example, Athenæum, 7 July 1860, pp. 25--6, reproduced in Correspondence vol. 8, Appendix VI).
- f4 2869a.f4According to the report of his paper in the Athenæum (see n. 3, above), Daubeny questioned the final cause of sexes in plants in view of the allegedly identical results of sexual and asexual reproduction. Daubeny cited various possible uses of sexual reproduction in plants, such as the provision of fruit for food, the gratification of the human senses, and the spatial dissemination of species, but contended that CD's theory of natural selection, subject to its acceptance, offered a more plausible and universal final cause than these. CD's own earlier interest in the final cause of sexual difference is reflected in his Notebooks: `My theory gives great final cause … of sexes …: for otherwise, there would be as many species, as individuals&lldots; [I]f my theory be true then the formation of sexes rigidly necessary' (Notebook E, 48--9; see also Notebooks, Notebook C, 236, Notebook D, 167). In Origin, however, CD confined himself to more general observations on the origin of sexual reproduction, such as, for example, `that it is a general law of nature … that no organic being self-fertilises itself for an eternity of generations' (Origin, p. 97). In his `Provisional hypothesis of pangenesis', CD again considered the final cause of sexual reproduction (see, for example, Variation 2: 362). For recent discussions of the teleology implied in the nineteenth-century use of the term `final cause', and of the teleology implied in CD's writings in particular, see England 2001 and Sloan 2001.
- f5 2869a.f5During the previous decade, several publications on parthenogenesis had appeared, for example R. Owen 1849 and Siebold 1857, annotated copies of which are in the Darwin Library--CUL (see Marginalia 1: 656--7, 756--7). These were followed by Thomas Henry Huxley's paper on parthenogenesis in aphids, which challenged Richard Owen's explanation of the phenomenon (T. H. Huxley 1858; see also Correspondence vol. 6, letter to T. H. Huxley, [before 12 November 1857]). In the first edition of Origin there is no reference to parthenogenesis, but CD added a single reference in the second edition, published on 7 January 1860, in the phrase `with the exception of the curious and not well-understood cases of parthenogenesis' (Origin 2d ed., p. 96).
- f6 2869a.f6This quotation has not been found in Huxley's writings. It appears to derive from `It is a wise father that knows his own child', Shakespeare, Merchant of Venice, 2.2.72--3 (S. Wells and Taylor eds. 1988). Huxley's work on parthenogenesis in aphids prompted him to question the necessity of the male in reproduction (T. H. Huxley 1858, p. 220).
- f7 2869a.f7Daubeny held that sexual reproduction in plants provided a mechanism for variation, whereas asexual reproduction produced `a mere counterpart' of the parental stock (see Athenæum, 7 July 1860, pp. 25--6; see also Daubeny 1860a).
- f8 2869a.f8Gemmation in this sense means `the formation of a new individual by the protrusion and complete or partial separation of a part of the parent' (OED). CD's `case of a trifling variation' propagated by the vegetative reproduction of an animal in coral has not been identified. For CD's later discussion of asexual reproduction and variation, see Variation 1: 374 and 2: 358--9, 371--3.
- f9 2869a.f9See n. 7, above.
- f10 2869a.f10CD's point about variation in plants raised by gemmation was cited by Daubeny in a footnote, with a reference to this letter (Daubeny 1860a, p. 23 n.). `Sports' are new varieties that arise from mutations, chiefly in buds, and are then propagated by vegetative reproduction. CD gave numerous examples of sports in Variation 1: 373--411. As examples of variation independent of sexual reproduction, sports were a challenge to Daubeny's view; see also Correspondence vol. 8, letter to J. S. Henslow, 16 July .
- f11 2869a.f11CD alludes to the sentence `Intercrossing plays a very important part in nature in keeping the individuals of the same species, or of the same variety, true and uniform in character' in Origin, p. 103. CD maintained this view in all editions of Origin. There are further details of his work on the role of crossing in the origination of species in Natural selection, p. 271, where he states: `Intercrossing will prevent or retard the process of natural selection; but here we are involved in much doubt.'