Speculates about cause of inclination in unusual columns of lava. Suggests CL check with William Hopkins about sliding movements in viscid matter.

Comments on CL’s expedition to Madeira.

Discusses possibility of publishing a sketch of his views.

Comments on CL’s letter [1862].

Mentions various geological topics.

Asks to borrow publication by Heer.

Mentions flight of Colymbetes over ocean.

Recalls visit by Wollaston.

Notes views of Hooker and Huxley on species.

Mentions ability of ducks to transport plant seeds.

Condemns theory of Edward Forbes and others that many islands were formerly connected to South America by now submerged continents.

Criticises at length the concept of submerged continents attaching islands to the mainland in the recent period. Notes drastic alteration of geography required, the dissimilar species on opposite shores of continents, and differences between volcanic islands and mountains of mainland areas. Admits sea-bed subsidence, but not enough to engulf continents. Denies that theory can explain island flora and fauna.

Considers Edward Forbes’s idea a check on study of dissemination of species.

Discusses theory of submerged continental extensions. Objects that if it is applied to one island, it must be applied to all. Admits that some volcanoes may have been associated with subsidence, in contrast to his former view. Cites evidence from S. American Cordillera. Doubts that elevation associated with volcanoes is merely local, and that great ocean areas are necessarily sinking.

Says he will make his essay [on species] as complete as possible and will discuss CL’s Principles.

Thanks CL for loan of [Matthew Fontaine?] Maury’s map.

Discusses possibility of submerged continental extension including Madeira, Canaries, and Azores.

Mentions icebergs as carriers of European plants.

Hooker’s work on Antarctic flora.

Comments on coolness of tropics in glacial period and consequent migrations. Hooker’s views on this.

Illnesses of Mrs Horner and Emma Darwin.

Death of Sarah Elizabeth Wedgwood.

Mentions work on his "Big Book" [Natural selection].

Remarks on J. A. H. de Bosquet’s discovery of a Chthamalus in the Chalk.