shortly a large bundle of M.S. but unfortunately I cannot for a week, as the three first chapters are in three copyists' hands". He bowed to Murray's objection to "abstract" in the title, though he felt it excused the lack of references, but wanted to keep "natural selection" which was "constantly used in all works on Breeding", and hoped "to retain it with Explanation, somewhat as thus",— Through Natural Selection or the preservation of favoured races. On 31 March Darwin 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 ⅔ 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 first edition and by Darwin's death in 1882 the book was in its sixth edition, earning Darwin nearly £3000). On 5 April, Darwin sent Murray the first three chapters, and a proposal for the book's title. An early draft title page suggests On the Mutability of Species. Murray cautiously asked Whitwell Elwin to review the chapters. At Lyell's suggestion, Elwin recommended that, rather than "put forth the theory without the evidence", the book should focus on observations upon pigeons, briefly stating how these illustrated Darwin's general principles and preparing the way for the larger work expected shortly: "Every body is interested in pigeons." Darwin responded that this was impractical: he had only the last chapter still to write. In September the main title still included "An essay on the origin of species and varieties", but Darwin now proposed dropping "varieties". With Murray's persuasion, the title was eventually agreed as On the Origin of Species, with the title page adding by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life. In this extended title (and elsewhere in the book) Darwin used the biological term "races" interchangeably with "varieties", meaning varieties within a species. He used the term broadly, and as well as discussions of "the several races, for instance, of the cabbage" and "the hereditary varieties or races of our domestic animals and plants", there