Discussion of ducks. CD asks for information on a domestic Chinese race about which Robert Swinhoe wrote to CD. Compares Chinese duck with Anas poecilorhyncha and Boschas.

Notes improvement in health.

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.

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.

Has returned memorial to Chancellor of Exchequer; thanks CL for his note.

Lengthy remarks on cool period. Did not know of CL’s interest. New facts in new German and English [4th] editions of Origin will be too late for CL’s use. CD’s ten-year-old MS on cool period is available.

Gives details of enclosed MS on cool period. Mentions Hooker’s opposed "axis of the earth" view. Causes of glacial period are beyond CD; "cannot believe change in land and water being more than a subsidiary agent".

Thanks for sending facts on birds admiring themselves; mentions use in new edition [4th] of Origin.

The apparent difference in arm lengths of compositors is due to a drooping shoulder. File-makers stand in a peculiar position and call one of their legs the hind leg.

Has not seen K. E. von Baer’s paper ["Über Papuas und Alfuren", Mem. Acad. Imp. Sci. St.-Pétersbourg (Sci. Nat.) 8 (1859): 269–346], but has read extract.

Knew of case of hairy and toothless family through John Crawfurd, Journal of an embassy from the Governor-General of India [2d ed. (1834)].

Working on causes of variability.

Disappointed to put off CL’s visit because of illness of CD’s sister [Susan], but hopes to see him in October.

Thanks for lending pamphlet [L. Agassiz, Geology of the Amazons]. Agassiz has written "wild nonsense".

Refers to a translation of Pictet and Humbert’s "capital" paper on fossil fish ["Recent researches on the fossil fishes of Mount Lebanon", Ann. & Mag. Nat. Hist. 3d ser. 18 (1866): 237].

Hooker’s lecture at BAAS Nottingham meeting.

Comments on proofs [of Principles of geology, 10th ed. (1867–8)]: CL does not allude to the specialisation of classes.

Discusses CL’s argument from the absence of Cetacea in Secondary rocks;

finds his discussion of man "superfluous and too orthodox".

More comments on proofs [of CL’s Principles of geology, 10th ed.]. Discusses permanence of continents and other points.

Refers to passage describing evaporation of snow in Journal [of researches, pp. 277–8].

Cites astronomers’ views on increasing length of day.

Says Jacob W. Velie wants to exchange birds’ skins with European naturalist.

Comments on meaning of "Darwinism".

Encloses papers from Practical Entomologist.

Discusses Ornithorhynchus paradoxus

and his paper on willow galls.

Mentions human skull found in California.

Thanks CL for copy of his "grand book" [Principles of geology, 10th ed., vol. 1 (1867)]. Congratulates him on additions.

Mentions visit to E. A. Darwin.

Encloses note for Mr Corbet.

Asks for reference to EB’s article about tame deer on island in Aral Sea.

Encloses a portion of a letter from B. D. Walsh [5319] concerning an American interested in exchanging birds’ skins.