Ɛpsilon

From Robert McLachlan   23 April 1877

39, Limes Grove, | Lewisham, S.E.

23 Apl. 1877

Dear Sir

I take this opportunity of thanking you very much for your support in my now succesful candidature for Royal. Soc.1

You probably know that the Arctic insects have been entrusted to me for working-out.2 There is one point that I think may be of special interest to you: up to the extreme point reached (nearly 83o N.) a Bombus was observed, & it always frequented the flowers of Pedicularis hirsuta.3 I believe that this flower is one in which cross-fertilization is almost absolutely necessary or self fertilization not easy, but shall be glad to be set right if I am wrong. Presuming it to be necessary, it is of great interest to find the principle carried out in these high latitudes, where the continuous existence of insect-life in a given locality, must be somewhat precarious. There are at least 6 (perhaps 8) species of Butterflies from the extreme North, & fine handsome insects, Colias 1 species; Argynnis 3 (perhaps 5) sp.; Chrysophanus 1 sp.; Lycæna 1 sp.4

I am | Yours faithfully | R. McLachlan

C. Darwin Esq FRS. &c &c

CD annotations

Top of letter: ‘Answered’5 ink
1
CD had signed the certificate, dated 10 February 1876, proposing McLachlan for election to the Royal Society of London (Royal Society archive, GB 117, EC/1877/11). CD had supported McLachlan’s earlier application for fellowship in 1874 as well (see Correspondence vol. 22, letter from H. T. Stainton, 15 January 1874). The council of the Royal Society had drawn up a list of candidates recommended for election at their meeting of 19 April 1877, and evidently informed the successful candidates (Royal Society council minutes, CMO/XV). Although the formal election took place on 7 June 1877, those recommended by the council were always elected by the fellows.
2
The British Arctic Expedition of 1875–6 was led by George Strong Nares (ODNB). McLachlan’s ‘Report on the Insecta’ was published in the Journal of the Linnean Society of London (M‘Lachlan 1877).
3
See M‘Lachlan 1877, pp. 101, 106; the species described from specimens collected as far north as 81° was Bombus balteatus (golden-belted bumblebee). Pedicularis hirsuta is hairy lousewort; like most Arctic species of Pedicularis, it is entomophilous and is pollinated by both bees and flies, but also self-pollinates above the northern limits of these insects (Savile 1964, pp. 254–5).
4
In his report, McLachlan described Colias hecla (Arctic sulphur) and C. boothii (a synonym of C. tyche boothii, Booth’s sulphur), Argynnis polaris (a synonym of Boloria polaris, Polaris fritillary) and A. chariclea var. obscurata (a synonym of Boloria chariclea arctica), Chrysophanus phloeas var. fieldeni (a synonym of Lycaena phlaeas, small copper), and Lycaena aquilo (a synonym of Polyommatus aquilo; M‘Lachlan 1877, pp. 108–11).
5
CD’s reply has not been found.

Please cite as “DCP-LETT-10939,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-10939