From H. W. Bates 28 May 1868
Royal Geographical Society | 15, Whitehall Place, S.W.
May 28 1868
My Dear Mr Darwin
Being our Anniversary week I have been very much occupied, even my leisure hours taken up by foreign Visitors & medallists; otherwise I should have written before to tell you that I went to Janson on Saturday afternoon & looked out a few beetles for you.1 He wrote the tickets specifying name & sex, whilst I was there & I hope has fixed them to the right specimens. In Geotrupes there is scarcely any external difference between ♂ & ♀ other than a row of denticulations along the under surface of the anterior tibiæ; these tibiæ have the usual row of teeth on the outer edge in both sexes but ♂ ♂ have in addition this row of small irregular sized teeth quite underneath. I picked you two females & one ♂ of one Geotrupes; a ♂ & ♀ Geotr. Typhœus, & ♂ & ♀ Lethrus, a most extraordinary being closely allied to Geotrupes, its habits described (I think) in Kirby & Spence’s “Introduction”. Luckily I found at Janson’s both sexes of Onitis furcifer.2 He promised to try to get Chiasognathus for you.3
The Dynastidæ are remarkable for stridulating organs, their classification being founded to some extent on these organs: as an example I send you ♂ & ♀ Oryctes.4 Janson is a very good Coleopterist & a very fair dealing man; he will supply you with anything in his power.
Yours sincerely | H W Bates
He has been occupied with Royal Geographical Society anniversary meeting, but did go to Janson and selected various specimens for CD, some of which have remarkable stridulating organs.
The habits of Lethrus are found in Kirby and Spence’s Introduction [to entomology, 7th ed. (1856)].
Please cite as
Darwin Correspondence Project, “Letter no. 6214,” accessed on 25 July 2016, http://www.darwinproject.ac.uk/DCP-LETT-6214