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