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 this was a common pattern. Darwin discussed ways that species could be dispersed across oceans to colonise islands, many of which he had investigated experimentally. Chapter XII continues the discussion of biogeography. After a brief discussion of freshwater species, it returns to oceanic islands and their peculiarities; for example on some islands roles played by mammals on continents were played by other animals such as flightless birds or reptiles. The summary of both chapters says: ... I think all the grand leading facts of geographical distribution are explicable on the theory of migration (generally of the more dominant forms of