On the Origin of Species wrote to Murray in confirmation, and listed headings of the 12 chapters in progress: he had drafted all except "XII. Recapitulation & Conclusion". Murray responded immediately with an agreement to publish the book on the same terms as he published Lyell, without even seeing the manuscript: he offered Darwin of the profits. Darwin promptly accepted with pleasure, insisting that Murray would be free to withdraw the offer if, having read the chapter manuscripts, he felt the book would not sell well. (eventually Murray paid £180 to Darwin for the 1st edition and by Darwin's death in 1882 the book was
On the Origin of Species to Races of Man", but did not add text on this topic. In "On the Origin of Species", Chapter VI: "Difficulties on Theory" Darwin mentions this in the context of "slight and unimportant variations": I might have adduced for this same purpose the differences between the races of man, which are so strongly marked; I may add that some little light can apparently be thrown on the origin of these differences, chiefly through sexual selection of a particular kind, but without here entering on copious details my reasoning would appear frivolous." When Darwin published "The Descent of Man, and Selection