Discusses Louis Agassiz’s theory of the glaciation of Brazil.

Discussion of Mrs Agassiz’s letter [to Mary Lyell, forwarded to CD] regarding S. American glacial action,

with comments on Bunbury’s letter on temperate plants.

Refers to opinions of Agassiz, David Forbes, Hooker, and CD on glacial period and glaciers.

Wishes he had published a long chapter on glacial period [Natural selection, pp. 535–66] written ten years ago.

Tells of death of his sister, Catherine, and other family matters.

Thanks CL for Hooker’s letter.

Discussion of Hooker’s views on glacial action and temperature with specific reference to S. America.

His squabbles with Hooker on transport of seeds via water currents,

temperate plants, and preservation of tropical plants during cooler period.

Expresses interest in seeing Agassiz’s letter.

Discusses CD’s and J. D. Hooker’s letters to Lyell concerning Louis Agassiz’s theory of the glaciation of the Amazon basin in Brazil.

Comments on errors [in Origin] pointed out in C. J. F. Bunbury’s letters.

Mentions CD’s notes on Drimys, Fuchsia, and fossil mammals of Brazilian caves.

Sorrowful that his work must be put aside because Murray wants a new [4th] edition of Origin. Remarks on changes to be made regarding Organ Mountains and Agassiz’s glacial markings.