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Darwin Correspondence Project

From Robert McLachlan   13 March 1879

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

13 March 1879

My dear Sir

I return the proof: it required only the slightest correction in the points you specially allude to.1

The occurrence of caddis-worms between the leaves of Bromeliāē is of great interest: the subject was brought before a recent meeting of the Entomol. Soc., & is mentioned (with some details) in the Proceedings, which you no doubt have.2

I have a lot of interesting facts & specimens from Fritz Müller in Trichoptera. They only arrived a week or two ago, & I have not yet completed my observations on the materials.3

With regard to the fringed legs of the pupaē. The fringes exist chiefly in those families & genera that inhabit still or slowly-moving water. I have just been writing on the subject for Pt. viii of my work on European Trichoptera, which treats on the genus Rhyacophila & others— Ryacophila frequents the most rapid torrents & waterfalls.4 The legs of the pupa-e are not fringed— fringes would be useless. The pupa must reach the surface by some method other than by swimming, for if it attempted the latter, it would be swept down by the torrent. I imagine that it contrives to crawl along the rocks &c, until it reaches the surface, in which it is aided by very strong tarsal claws. In all Families of Trichoptera I should say the pupaē with unfringed legs are the most numerous.

Dr. Müller is doing good work on the habits of Brazilian Trichoptera; he naturally suffers from incomplete works of reference.5 He appears to fall in with my views as to the near relationship of Trichoptera & Lepidoptera, as opposed to the American school which disposes of all difficulties in the Linnean Order Neuroptera by calling it a collection of “synthetic types”, whatever that may mean!6

Yours very faithfully | R. McLachlan

C. Darwin Esq. FRS. &c &c

Footnotes

See letter to Robert McLachlan, 12 March [1879]; CD had submitted the letter from Fritz Müller, 21 January 1879, to Nature for publication and wanted to ensure that the names of the Trichoptera (the order of caddisflies) mentioned were spelled correctly.
Fritz Müller had sent several larvae cases to McLachlan, who exhibited them at a meeting of the Entomological Society of London on 4 December 1878 (see Transactions of the Entomological Society of London (Proceedings) (1878): lv–lvi).
McLachlan exhibited the cases and specimens of sixteen species of Brazilian caddisflies sent to him by Müller at a meeting of the Entomological Society of London on 2 April 1879; excerpts from Müller’s letter to McLachlan with notes on his observations and some comments by McLachlan were published in Transactions of the Entomological Society of London (Proceedings) (1879): vi–viii.
See letter from Fritz Müller, 21 January 1879, for Müller’s explanation of the function of fringes in larval caddisflies. The eighth part of McLachlan’s Monographic revision and synopsis of the Trichoptera of the European fauna (McLachlan 1874–80) was published in May 1879.
Müller had published a paper ‘Sobre as casas construidas pelas larvas de insectos Trichopteros da provincia de Santa Catharina’ (On the cases constructed by the larvae of Trichoptera insects of the province of Santa Catharina; F. Müller 1878b); his joint paper ‘Phryganiden-Studien’ (Studies on Phryganeidae; F. Müller and Müller 1879) and his paper ‘Notes on the cases of some south Brazilian Trichoptera’ (F. Müller 1879b) were published in 1879.
In F. Müller and Müller 1879, p. 388, in a section that compared the wing neuration of Trichoptera to that of Lepidoptera, Müller had quoted from McLachlan 1870, p. 100, in which McLachlan objected strongly to the wide separation of these groups suggested by the American entomologist Alpheus Spring Packard Jr, who placed them within the Linnaean order Neuroptera. Müller noted that both the number and the branching pattern of the veins in the wings of Trichoptera and Lepidoptera matched precisely (F. Müller and Müller 1879, pp. 388–9).

Bibliography

McLachlan, Robert. 1870. On new forms, &c., of extra-European trichopterous insects. [Read 2 June 1870.] Journal of the Linnean Society of London (Zoology) 11 (1870–3): 98–141.

McLachlan, Robert. 1874–80. A monographic revision & synopsis of the Trichoptera of the European fauna. London: John van Voorst.

Müller, Fritz. 1878b. Sobre as casas construidas pelas larvas de insectos Trichopteros da provincia de Santa Catharina. Archivos do Museu Nacional do Rio de Janeiro 3: 99–124.

Müller, Fritz. 1879b. Notes on the cases of some south Brazilian Trichoptera. Transactions of the Entomological Society of London (1879): 131–44.

Müller, Fritz and Müller, Hermann. 1879. Phryganiden-Studien (mit einer Einleitung von Herm. Müller). Kosmos 4 (1878–9): 386–96.

Summary

Returns to CD a corrected proof [of "Fritz Müller on a frog having eggs on its back", Nature 19 (1878–9): 462–4].

Discusses adaptations of the pupae of, and Fritz Müller’s work on, Trichoptera.

Letter details

Letter no.
DCP-LETT-11930
From
Robert McLachlan
To
Charles Robert Darwin
Sent from
Lewisham
Source of text
DAR 171: 2
Physical description
ALS 4pp

Please cite as

Darwin Correspondence Project, “Letter no. 11930,” accessed on 4 March 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-11930.xml

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