Thanks him for Balanus specimens. Comments on his findings. A large Acasta in the wet state would be valuable. Asks JSB to mention his work to J. T. Quekett at the College of Surgeons.

[Valediction only.] CD note on verso: Athenaeum/48/p. 839 "E. Forbes on genera being continuous in time––good––fact".

Testimonial recommending B. Waterhouse Hawkins [for a teaching post].

Suggests various remedies for toothache.

Seeks excuse from jury duty on grounds of ill health.

CD asks if he may have the use of the cirripedes JS collected in Portugal. He will need to break up or make a section of at least one of each species.

Expresses admiration for JS’s paper on Malta ["On recent depressions in the land", Q. J. Geol. Soc. Lond. 3 (1847): 234–40], with its striking demonstration of the change of level between land and water there discovered.

Thanks WCW for his article ["Microscopical objects found in mud of Levant", Mem. Lit. & Philos. Soc. Manchester 2d ser. 8 (1848):1–128]. Comments on it; offers to send Ascension Island specimens. Urges WCW to re-examine coal-beds for Infusoria to determine whether intervening beds were deposited by sea-, brackish, or fresh water.

Undertakes to write geological part of Admiralty Instructions [A manual of scientific enquiry (1849), Collected papers 1: 227–50]. Has doubts as to his success.

Has been invited to contribute geological instructions [to J. F. W. Herschel, ed., Manual of scientific enquiry (1849); Collected papers 1: 227–50]. Asks RO whether remarks on coral reefs appertain to geology rather than zoology.

Looks forward to visit by Owens.

Invites him to dinner on Saturday the 12th. Charles and Mrs Lyell, Edward Forbes, Richard Owen, and Thomas Bell coming also.

"Will you bring your map of S. America … and we will have a talk over it."

Thanks the Trustees of the British Museum for entrusting to him the collection of Cirripedia and allowing him to disarticulate one specimen of each species.

Discusses loan of cirripede specimens from the British Museum and problems of classification. Encloses a note of thanks to be laid before the Trustees [see 1153].

Thanks for present of fossil Balani.

Thanks also for JS’s request to David Landsborough to send barnacle specimens.

Invites GRW to a dinner party with other scientists.

CD cannot find the lagoon-island mud that WCW asked about, but he sends other geological specimens he hopes will be interesting.

Thanks RC for information on hand-level; he has recommended it in his "Instructions" ["Geology", Collected papers 1: 227–50].

Asks for the reference in which JP states that some erratic boulders came from a lower to a higher level. CD is writing a paper ["Transportal of erratic boulders", Collected papers 1: 218–26] in which he believes he has the true explanation. Would like as many instances, with details, as possible.

Though correspondence has never ebbed so low, CD is constantly in his thoughts.

Observations on cheetahs used as domesticated hunting animals.

Finds geographical barriers sometimes separate species, but also finds species that remain separate where there are no barriers to migration.

Colour "individuates" isolated animal species.

Plains and alpine animal distribution show altitude not strictly analogous to latitude.

Impact of timber cutting on climate has led to extinction of crocodiles.

Will discuss coal formation in letter to Edward Forbes.

CD often asked whether isolated mountains in southern latitudes had closely allied representatives of Arctic and north temperate plants; JDH has found a representative barberry.

Making for Darjeeling via Calcutta.

Thanks for sending cirripedes. Cannot make out the label, so can JCR tell him the bank and the depth. Hopes to keep the specimens for 6 or 8 weeks before returning them.

Arranges to pay subscription on 15 Feb and 16 Aug as requested by Mr Mason.