To J. S. Henslow   2 April [1860]

Down Bromley Kent

Ap. 2d.

My dear Henslow

I write one line to remind you to be so kind as to give me a sketch & account of the wasp’s comb in transitional state from horizontal to vertical, & the country whence procured, &c., &c.—1

As I am in the way of reminding, I will remind about Anacharis—viz how far it has travelled up the Cherry Hinton-Brook—how long the journey has consumed, the means &c.—2 I have since you were here found statement by Babington that this plant is now not so common as it was at first introduction.3 I shd. very much like to have this confirmed, & what creatures destroy it.—   Lastly what plants in any particular spot or pond it has nearly or quite exterminated by taking their places.? Here is a goodly list of queries!

Many thanks for your Sermon & for copies of the Examination Papers received some time since.4 Sedgwick’s was not very fair towards the Students;5 but Murray, the Publisher, thought it splendid for selling copies to the unfortunate Students.—

My dear Henslow | Yours very truly | C. Darwin

Endorsement: ‘1860’

1
Henslow had visited Down from 14 to 16 February 1860 (Emma Darwin’s diary), during which time he and CD may have discussed wasps’ nests. Henslow had previously sent CD part of a wasps’ nest (see Correspondence vol. 7, letter to J. S. Henslow, 10 January [1859]).
2
Anacharis or Elodea, an introduced water-weed, had flourished in English streams to such an extent that rivers were being choked by it. Cherry Hinton is a village near Cambridge. Soon after the introduction of Anacharis alsinastrum to the Cambridge Botanic Gardens, the plant ‘made its escape through a waste pipe, found its way into the Cam, and in 1852 impeded navigation and threatened to injure the drainage of the fen country’ (A. M. Babington ed. 1897, pp. lxxiii–lxxiv).
3
The source of Charles Cardale Babington’s remarks has not been traced. Babington was the first to describe A. alsinastrum (C. C. Babington 1848).
4
Henslow served on the examination boards for Cambridge and London Universities (see Russell-Gebbett 1977, pp. 69–73). In February 1860, the Cambridge University Senate enacted new regulations whereby those students who passed the Natural Sciences Tripos with honours qualified for admission to the degree of Bachelor of Arts. A Board of Natural Sciences Study was directed to establish the examination requirements and appoint examiners. See Winstanley 1947, pp. 187–8.
5
Adam Sedgwick. One of the aims of the new regulations was to raise the level of achievement of graduates by forcing candidates to concentrate more on individual subjects for the examination (Winstanley 1947, p. 188).

Manuscript Alterations and Comments

2.3 by Babington] interl; caret over semicolon
2.4 at first introduction.] interl
3.3 selling] before omitted point

Please cite as “DCP-LETT-2742,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-2742