Dear Sir

I sent the M.S. to you yesterday. I write now to tell you, that I find so much to add about the Fuegians,¹ & consequently so much more to condense & almost rewrite in the scientific part, that I cannot help fearing that possibly I may not have the second number ready having to correct press of 1^st number for press at the end of this month. I think I shall, but not being sure, I thought it w^d be better not to take you by surprise. It will depend on my health, which lately has been very good; I earnestly wish to complete it as soon as possible. I shall be able to judge certainly by the 20^th of this month:

I presume you have something else which, if required, c^d. come out, between two of my numbers

Yours very faithfully | C. Darwin