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.

As JH has accepted the superintendency of the Admiralty Manual he will try to undertake the geological part, but it will take time as he is busy on another project.

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.

At Madras [Chennai] JDH asked about cheetahs. Conveys observations on their domestication & hunting. Describes hawking practices & birds used. Observes that natural features separate species but this is only one factor, e.g. different antelopes found on either side of River Soane which should not be a barrier to migration. The different types of Indian elephant also an example of races in districts. Discusses kinds of wild & domesticated dogs & cattle. The native Bison is extinct. Sciurus maximus: Peninsular Squirrel, is example of locality-specific colouring. From behaviour of alpine & plain species observes animals are more able to adapt to heat than cold, altitude a factor. JDH wants a specimen of an alligator from Zillah Shahabad. Deforestation changing climate & killing crocodiles. Observes Sand Martins nests colonised by Phalangium spiders & comments on diurnal migration of Neilgherry Ghaats [Nilgiri Ghats] swallows. Plains are alluvial deposits with interesting mineralogy. Will send Forbes a letter re. coal formation. Re. botany, as Darwin is interested in vegetation of isolated mountains, JDH comments on flora of one he climbed incl. barberry. Has found new species of Vallisneria. 4 Mar: JDH left Williams' geological survey to go to Mirzapore, Calcutta [Kolkata] & Darjeeling in Sikkim Himalaya. JDH's address is botanic garden Calcutta, care of Falconer. Recounts passage out to India. Has stayed with Sir L. Peel, Mr Colvile nephew of Lord Auckland, & at Government House. JDH hopes to join the Geographical Survey of Kamaon by naturalists, covering Sewalik hills to Tibet & Simla to Nepal. Thomson is in Yarkand studying geology & botanical geography, Cunningham in Cashmere [Kashmir] & Strachey in Chinese Tibet. Mentions Equus hermionus, an Auroch horn, his health & plan to go to Cherra Poonjee in Sylhet. Mar 8: en route to Bhagulpore down Ganges. Feb 16: will look for cirripedia for Darwin in Borneo, sends regards to Lyells & recommends Griffith's Journals.