Regrets J. D. Hooker did not visit Berlin.

Describes legal difficulties of Ernst Dieffenbach.

Lists species of Infusoria found in dust samples. Discusses origin of Atlantic dust. Discusses Infusoria in cosmetic paint from Tierra del Fuego and Patagonian earth. Thanks CD for samples. Would like samples from sea-bed.

Discusses chemical reaction involving common salt and carbonate of lime.

Reports that he has an offer of an estate of about 325 acres that CD may find suitable.

JDH recommends Augustin de Saint-Hilaire’s Leçons de botanique [1841]. Relates opinions of European botanists on migration and plant distribution.

A Tasmanian Cyttaria is same species as CD’s Fuegian fungus. Did the species originate on the beeches of Fuegia or of Tasmania?

JDH gives interpretation of Vestiges.

John McCulloch, J. F. Schouw, and Lamarck on the species question.

Discusses table of Atlantic dust samples. Thinks dust came from South America.

Discusses Patagonian tuff samples.

Answers CD’s query about material from Pampas. Believes deposit made in brackish water.

Criticises account of Atlantic dust in F. J. F. Meyen [Reise um die Erde (1834–5)].

First part of "Galapagos flora" ["Plants of the Galapagos Archipelago", Trans. Linn. Soc. Lond. 20 (1851): 163–233] finished but not printed.

Details of distribution of Galapagos flora. Peculiarity of island floras.

Leaves for Edinburgh on Wednesday.

Discusses the microscopic structure of rock samples from Chile and the Pampas. Describes organic remains found in the samples.

Has marked probable depths of the specimens on CD’s list of S. American shells. Asks for details which would provide more precise conclusions. [See South America, p. 226.]

Discusses insects collected by CD on St Paul’s Island and the Galapagos.

Notes on Galapagos Coleoptera.

Is about to send his paper on Galapagos beetles to press. Has written some introductory material on which he invites CD’s comments.

Discusses his paper on CD’s Galapagos beetles ["Coleopterous insects … in the Galapagos Islands", Ann. & Mag. Nat. Hist. 16 (1845): 19–41] which he will forward when printed. Has drawn up descriptions of several other insects from CD’s collections.

The translation of Humboldt’s Kosmos [Cosmos (1846–58)] is delayed.

Gives instances of peculiar genera with several good species in very small islands. Scarcity of insects on islands.

JDH cannot prove that there is much hybridising, but does not see why there should not be. "Bother variation, development & all such subjects, it is reasoning in a circle I believe after all."

On marking and shipment of fossils.

Has met the artist, J. M. Rugendas.

Discusses British and French relations with Rosas government [of Argentina].

Raises some points for revision of CD’s Journal of researches.

Southern island floras. "The more I ponder upon Insular Floras the less inclined I am to admit the mutation of species to any very great amount."

Notes the islands, where known, on which CD’s Galapagos beetles were found. Remarks that in none of the species whose place of origin is known, does he have specimens from more than one island.

Answers CD’s questions relating to the flora of the Galapagos. [See 889.]

Informs CD about characteristics of certain species of Galapagos birds.

Discusses colour of Zenaida from the Galapagos.