Remarks that each of two species of Fagus separated by 1000 miles has a fungus that grows on it; the fungus species are probably closely allied.

Acknowledges election as Honorary Member of Shropshire and North Wales Natural History and Antiquarian Society.

Feels he cannot keep the gift of Gould’s "magnificent work" or take out a subscription now that he is a married man.

Illness has long delayed CD’s thanks for WCR’s meteorological pamphlets and geological reports. Mentions a reference to whirlwinds leaving rotary patterns in desert sand.

Birds has gone to the printer.

Continues "to collect all kinds of facts about ""varieties and species"" " for his "some-day work".

Would be grateful for descriptions of offspring of crossbred domestic animals.

In a revise [of Birds] CD has altered "Colaptes Chilensis Vigors" to "Chrysoptilus Chilensis G. R. Gray". Is that right?

Sends proof of index of final number of Birds for checking.

Answers a number of queries from Lyell concerning geography and geology of Chiloé Island and its relationship to the Cordilleras.

Asks about "perched rocks" on Jura and notes their relevance to Louis Agassiz’s theory. Discusses Agassiz’s view on Jura.

Mentions seeing Robert Brown.

Notes R. I. Murchison’s discovery of shells in central England.

Weakness of negative evidence.

Looks forward to the paper on CD’s edible fungus specimen from Tierra del Fuego [read 16 Mar 1841; Trans. Linn. Soc. Lond. 19 (1845): 37–43].

Sends a correction: Fagus betuloides, not F. antarctica, is the common tree of Tierra del Fuego.

Discusses the role of ice in determining the geological features of the Jura. Mentions view of Agassiz. Objects to idea of "a [sea of ice] carrying rocks". Notes Agassiz’s earlier view of "ice expanded in the line of the Great Swiss Valley". Comments on Pentlands.

Has enjoyed reading LA’s book [Études sur les glaciers (1840)].

Hopes LA will pardon manner in which CD has alluded to his work on glaciers in his Journal of researches, of which he sends a copy.

Defends his theory [in "Parallel roads of Glen Roy" (1839), Collected papers 1: 87–137] against the view that the "roads" were formed by glacial action.

Discusses at length Louis Agassiz’s book [Études sur les glaciers (1840)] and Agassiz’s explanation of moraines. Defends his own theory of the importance of floating ice. Relates glacier theory to his own interpretation of Glen Roy.

Mentions a paper he is writing on South American boulders and till [Collected papers 1: 145–63].

The Smith, Elder & Co. account for the now published fifth number of the third part of the Zoology is presented.

Sends paper on erratic boulders [Collected papers 1: 145–63] to the Society. Has taken two months to complete it because of illness.

Thanks recipient for finding reference on carbonate of lime. Doubtful when he will publish his geological memoranda.

The third number of part four of the Zoology has been published. CD transmits the Smith, Elder & Co. account.

Doctors predict it will take years for CD’s constitution to recover.

Tells WAL where specimen of Cynoglossum sylvaticum may be seen growing.

Family news. Mainly concerned about Doddy’s [W. E. Darwin’s] health.