Ɛpsilon

From R. D. Fitzgerald   15 March 1877

Surveyor Generals | Offices Sydney

15th March 77.

Dear Sir

Accept my best thanks for your works on fertilisation and for the flattering reference to my Australian Orchids in the last.1 I have read them with great interest. I regret that the third part of my Orchids as yet unpublished was not in your hands as I believe you would have been interested in at least one peculiar modification to be described in it.2 Though of course there can be no doubt from your experiments that a cross is of advantage in general I am compelled still to believe that there are some plants so constituted as to dispense with it altogether or only to be crossed under the most exceptional circumstances and that the numbers of individuals to be found in any species is dependent on other causes and not on this circumstance of whether their seed comes from self or cross-fertilisation.

I have discovered a curious series of forms in Thelymitra between dependent and independent fertilisation and am inclined to believe that self fertilisation was the ancient method to which they are reverting or from which they are departing3

I remain Dear Sir | Yours truly | Robt D Fitzgerald

1
Fitzgerald’s name was on CD’s presentation lists for Cross and self fertilisation (see Correspondence vol. 24, Appendix III), and for Orchids 2d ed. (see this volume, Appendix IV). CD cited the first volume of Fitzgerald’s Australian orchids (Fitzgerald 1875–94) in Orchids 2d ed., pp. 89–91, 115, 127, and 279–81.
2
Fitzgerald 1875–94 was published in parts in two volumes. The first volume had seven parts, and the second, five parts. Vol. 1, part 3 was not published until June 1877; a copy is in the Darwin Library–CUL.
3
Thelymitra is the genus of sun orchids. In Orchids 2d ed., p. 127, CD discussed Fitzgerald’s observations of Thelymitra carnea (pink sun orchid) and T. longifolia (common sun orchid) being fertilised in the bud but noted that the flowers had some structures adapted for crossing. In Forms of flowers, p. 313, CD added Thelymitra to his list of genera that included cleistogamic species on the basis of Fitzgerald’s observation that the flowers in its native region never opened, but that they did not appear to be reduced in size (ibid., n.). For more on Fitzgerald’s studies of Thelymitra fertilisation, see Edens-Meier and Bernhardt 2014, pp. 175–81.

Please cite as “DCP-LETT-10893,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-10893