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.

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.

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

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."

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."

JDH’s grandfather’s death.

Collecting testimonials for the Edinburgh chair.

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

CD’s Cape Tres Montes plants.

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.

Answers CD’s queries arising from Flora Antarctica.

Would like CD to come to town and go over Galapagos plants with him.

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.

Thanks for Edward Forbes’s letter. Botanical evidence conflicts with parts of his theory but supports others. Is becoming more of a migrationist.

Bentham agrees with JDH on polymorphism.

JDH recognises the existence of "altered states" of continental species in island floras. The botanists’ difficulty in determining a new species is no grounds for dismissing the important question of altered forms.

Will look for Ascension plants for Ehrenberg.

French Galapagos collections confirm JDH’s view that plants arrived from north.

Cannot agree with Forbes on North Atlantic flora.

Botanical definition of "highness" and "lowness" usually means complexity and simplicity.

Some plants, such as aquatic ones, are cleistogamous. Cannot see why they should not be.

Hugh Falconer gives no specific objections to Forbes’s views.

Botanical contrast between Cape of Good Hope and the rest of Africa is as strong as that between Australia and India.

Wishes CD would leave off snuff.

Has done Edmondston’s Galapagos plants.

Dispute between Edward Forbes and H. C. Watson.

Cannot come to Down to meet B. J. Sulivan as W. H. Harvey is calling.

Plant distribution and soil nature.

Forbes’s modification of Watson’s types of vegetation.

JDH will write comparison of representative plant species of the N. and S. Hemispheres.