Continues prior letter of this date. Has received CD’s [1202]. Thanks CD for saving his correspondence.

Sent "a yarn about species" in October mail.

Some "puerile" JDH letters printed in Athenæum.

Requests CD extract anything valuable from his letters to CD and Lyell for Athenæum.

CD’s complemental males in barnacles wonderful.

Warns CD to drop his battle about perpetuity of names in species descriptions.

CD’s health and his father’s death have delayed his answer. Describes J. M. Gully’s water-cure.

JDH’s Galapagos papers [Trans. Linn. Soc. Lond. 20 (1851): 163–233] have excellent discussion of geographical distribution, but why no general treatment of affinities?

CD’s views on clay-slate laminae.

Turmoil in Royal Society between naturalists and physicists.

Does not recommend that JDH publish extracts of his letters from India in the Athenæum.

CD criticises JDH’s observations on glacial deposits in Himalayas as insufficiently clear and detailed.

CD will live to finish barnacles and make a fool of himself over species.

Pleasure at receiving CD’s scientific letters to JDH and Hodgson.

The H. Wedgwoods’ pecuniary loss.

Condolences at CD’s father’s death.

Rajah harasses JDH’s work. Lack of supplies, rain, malarial valleys, and landslips make going difficult. Cannot get into Tibet.

"Twenty species [of plants] here [Camp Sikkim] to one there [Tierra del Fuego?] always are asking me the vexed question, ""where do we come from?""."

From observation of terraces descending to steppes and plains of India, he thinks that the Himalayas were once a grand fiord coast.

Has information CD requested on Yangsma valley. JDH’s detailed hypothesis of origin of dam there. Does not agree with CD’s interpretation.

CD partly right. JDH was calling "stratification" what CD calls "foliation". Answers CD’s question on cleavage foliation in Himalayas. Glacial action.

Charmed by CD’s Admiralty instructions on geology [in Manual of scientific enquiry (1849), Collected papers 1: 227–50], but complains he does not give prices of books and instruments he recommends.

CD thinks great dam across Yangma valley is a lateral glacial moraine.

Reports on Birmingham BAAS meeting.

Details of water-cure.

Barnacles becoming tedious; careful description shows slight differences constitute varieties, not species.

Lamination of gneiss.

Discusses books returned

and invites him to Down for a few days.

Congratulations on JDH’s safe return.

Henslow has sent CD’s S. American plants to JDH for examination.

Thanks for use of CD’s collection.

Comments and queries on the botany of the Southern Hemisphere.

Looks forward to seeing CD’s Galapagos plants.

Thanks JDH for short sketch of botanical geography of Southern Hemisphere. Comments on his own S. American collections and observations; notes other Galapagos collections.

Henslow has sent him CD’s Galapagos plants along with Macrae’s. JDH impressed by the island endemism, which "overturns all our preconceived notions" on centres of radiation. Describes the extent, and the sharp demarcation at longitude 60° W, of the American and European Northern Hemisphere floras. CD’s plants among those he is using to do Antarctic flora. Drimys winteri shows a graded series of states down the length of the South American continent.

Queries on ratios of species to genera on southern islands. CD’s observations on distribution of Galapagos organisms, and on S. American fossils, and facts he has gathered since, lead him to conclusion that species are not immutable; "it is like confessing a murder".

C. G. Ehrenberg would like some earth from Galapagos, Tierra del Fuego, and the Falklands; wishes to hunt for Infusoria.

Remarks on geographical divisions of the flora of the Southern Hemisphere.

JDH beginning Galapagos plants. Value of studying insular floras with respect to inquiries about adaptation of species.

Thanks for information for Ehrenberg.

Has just completed Volcanic islands.

Sends queries on Galapagos flora in particular and island floras in general; also on relationship of wide-ranging species to wide-ranging genera.

Island floras; relationships with mainland. Ranges of species in mundane genera.

Galapagos plants one-third done.

Affinity of Galapagos with nearest Pacific islands. Relationship between ranges of species in time and space. Comparison of Malden Island and Galapagos plants. Affinities of Oceania plants with continental floras.

Thanks for information on Malden Island. Comments on its plants and their relationship to the Galapagos flora. Discusses the flora of Oceania. Gives his opinion on the extent of the uniformity in species and forms amongst South Sea Islands. Large genera are more widely diffused and have a larger proportion of species with wide ranges.

Seeks advice on expense of preparing plates [for Flora Antarctica].

Advice to JDH on problems of printing and publishing.

Remarks on differences of species between islets of Galapagos group.