To G. H. K. Thwaites   13 February [1868]1

Down. | Bromley. | Kent. S.E.

Feb. 13th

My dear Thwaites

I wrote a little time ago asking you an odd question about Elephants, & now I am going to ask an odder.2

I hope that you will not think me an intolerable bore.— It is most improbable that you could get me an answer, but I ask on mere chance.— Macacus silenus has a great mane of hair round neck, & passing into large whiskers & beard, now what I want most especially to know is, whether these monkeys when they fight in confinement (& I have seen it stated that they are sometimes kept in confinement) are protected from bites by their mane & beard.3

Anyone who watched them fighting would I think be able to judge on this head. My object is to find out with various animals how far the mane is of any use, or a mere ornament.—4 Is the male Macacus silenus furnished with longer hair than the female about the neck & face? As I said it a hundred or a thousand to one against you finding out anyone who has kept or keeps these monkeys in confinement.—

Excuse me if you can, & believe me | Yours very sincerely | Ch. Darwin

1
The year is established by the relationship between this letter and the letter to G. H. K. Thwaites, 31 January [1868].
3
Thwaites forwarded CD’s query to Samuel Owen Glenie; see enclosure to letter from G. H. K. Thwaites, 22 July 1868. Macacus silenus (now Macaca silenus) is commonly known as the liontail macaque or wanderoo (see Kavanagh 1983).
4
CD concluded in Descent 2: 312 that ‘crests and tufts of hair’ on the heads of monkeys were probably acquired through sexual selection ‘exclusively as ornaments’.

Please cite as “DCP-LETT-5872,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-5872