Summary

Thanks for pleasant stay at Down.

Remarks on boulders found on southern islands.

Describes the alpine character of the Andes flora and relays information on other mountain floras.

Quotes instances of seeds that retained their vitality after being carried by ocean currents.

Sends notes on the comparative floras of New Zealand, Australia, and west coast of South America.

Encloses a copy of part of a letter from George Gardner in Ceylon concerning the European character of the mountain flora.

Summary

Differences in variability of species within a single genus. Further observations on Lycopodium.

Interested in Humboldt’s river with different floras on opposite banks, and other unexplained cases of very local distributions.

Summary

Suggests there is a direct relation between temperature and abundance of plant species.

Summary

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.

Summary

Thanks for CD’s comments on "sketch".

Lengthy discussion of geographical distribution and island floras.

Has been "delighted with" [Robert Chambers’] Vestiges [of creation (1844)].

Galapagos flora work goes on well.

Summary

Sends notes on Infusoria for Ehrenberg.

Comments on distribution of species in natural orders that have local distributions. Intermediate forms between species of Lycopodium.

Summary

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].

Summary

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.

Summary

Would like to visit on the weekend of 7–8 December.

Differences in floras of St Helena and Ascension.

Summary

Answer to CD’s query on genera and species ranges.

Comments on typical forms.

Preparing first part of Galapagos plants for printing.

Summary

The most experienced botanists argue for the "validity of species in nature". Against taxonomic "splitters".

CD’s Cape Tres Montes plants.

Summary

Previous letter [missing] on Edinburgh position was ill-tempered. Friends assure him that he ought to be thankful for opportunity to try for professorship.

Reports meeting with Humboldt in Paris.

Summary

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

Galapagos plants one-third done.

Summary

Discusses the connection between climate and vegetation. Believes that an equable climate is unfavourable to increase of species either by importation or modification of existing forms; illustrates his view with reference to particular floras. Hopes to acquire facts to support CD’s idea that isolation is important in producing new forms. Considers the floras of islands some of which do have distinctive species but others of which do not. Agrees that the wide ranges of cryptogams are a consequence of their means of dispersal. Asks for references to works on original creation and species mutability in order to get the best notions of "the (mad) theories of some men from Lamarck’s twaddle upwards".

Summary

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.

Summary

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.

Summary

Goes on the assumption that each species has one origin, is immutable, and migrates.

Disagrees with Gaudichaud[-Beaupré] that volcanic island species are polymorphous.

Some mundane genera vary, others do not (Senecio vs Gnaphalium).

John Lindley’s doctrine of longevity of trees is amazing.

Edward Forbes’s health is better.

Summary

Thanks for Journal of researches.

Puzzled over pea flower from Cape Tres Montes.

Thinks species a fair and most profitable subject for discussion, but has no formed opinion of his own.

Summary

Lyell has been strongly urging John Murray to publish CD’s book [Origin]. JDH feels Lyell overestimates the public interest in such works.

Gives examples of plants showing most marked varieties on the edge of their range.

Summary

Sends specimens of grasses from Ascension Island for CD to forward to Christian Gottfried Ehrenberg.

Includes list of indigenous flowering plants of Ascension Island.