Reactions to On the Origin of Species one hundred million years." Copies of the second edition were advertised as ready on 24 December, in advance of official publication on 7 January 1860. The "Saturday Review" of 24 December 1859 strongly criticised the methodology of Darwin's calculations. On 3 January 1860, Darwin wrote to Hooker about it: "Some of the remarks about the lapse of years are very good, & the Reviewer gives me some good & well deserved raps,—confound it I am sorry to confess the truth. But it does not at all concern main argument." A day later, he said to Lyell "You saw I suppose
On the Origin of Species to be separate species produced fertile hybrid offspring freely, and in other cases what were considered to be mere varieties of the same species could only be crossed with difficulty. Darwin concluded: "Finally, then, the facts briefly given in this chapter do not seem to me opposed to, but even rather to support the view, that there is no fundamental distinction between species and varieties." In the sixth edition Darwin inserted a new chapter VII (renumbering the subsequent chapters) to respond to criticisms of earlier editions, including the objection that many features of organisms were not adaptive and could not