JDH on "highness" of Coniferae: they are genuine Dicotyledons, not a link to cryptogams; that is a geologists’ fallacy. Thus they are highest plants in Carboniferous.

Does not agree with CD’s "elastic" species theory. Long correspondence with Lyell on this.

CD’s view requires only that ancient organisms resemble embryological stages of existing ones. Thus "highness" in plants is difficult to evaluate because they have no larval stages. Would compare highest members of two groups, rather than archetype, to determine which group was higher. Against Forbes’s polarity and parallelism.

Should like to examine the correspondent’s Madeira cirripedes but is too much occupied with other subjects of natural history.

JDH and F. W. Binney identify Calamites specimens as pith casts. They are cryptogams related to, but higher than, Lycopodiaceae and contradict progression.

Insects found in coal.

Lyell says Stonesfield slate marsupials are actually placentals.

JDH reading Alexander Braun on individuality ["Das Individuum der Pflanze in seinem Verhältniss zur Species", Abh. K. Akad. Wiss. Berlin (Phys. Kl.) (1853): 19–122].

Discusses specimen of Balanus crenatus.

Sorry JP’s children are ill.

Will come to Liverpool if well [for meeting of BAAS].

Sends beetle he cannot identify.

Reading J. O. Westwood [Introduction to the modern classification of insects (1839–40)] has reawakened his passion for entomology.

On individuality.

Huxley’s review exquisite, but too severe on Vestiges; sorry for ridicule of Agassiz’s embryonic fishes.

Stonesfield mammals.

J. O. Westwood deserves Royal Society Medal.

Will begin species work in a few days.

The land shells, both fossil and recent, of Madeira and Porto Santo have features peculiar to them, so RTL would have no difficulty in identifying them.

CD writes as the Treasurer of the Down Coal and Clothing Club and the Down Friendly Club, requesting subscriptions.

JDH’s contempt for R. I. Murchison.

There is a Cyperus species and a Pteris species endemic to hot volcanoes of Ischia. Why are there no other migrators?

Congratulates JDH on receipt of Royal Medal.

CD gathering facts on aberrant genera of insects.

Fossil leaves from Disko Island.

JDH to begin working out the botanical geography of the polar sea.

Has not forgotten CD’s request on aberrant species.

Has taken a house on Richmond Hill.

Sends list of aberrant forms of Curculionidae.

Discusses in detail the artificiality of Carl Johan Schönherr’s classification. Sound generalisations about geographical distribution depend on sound classifications. Warns against putting too much faith in current catalogues.

Calculating small number of species in aberrant genera of insects and plants.

Joachim Barrande’s "Colonies", Élie de Beaumont’s "lines of Elevation", Forbes’s "Polarity" make CD despair, as these theories lead to conclusions opposite to CD’s from the same classes of facts.

George Bentham’s list of aberrant plant genera. JDH appended the number of species in each genus according to E. G. Steudel’s catalogue [Nomenclator botanicus (1840–1)] and according to JDH and Bentham.

JDH speculates on effect of splitting Australia longitudinally on distribution; it becomes an argument for new creations.

In response to CD’s query, HCW says he cannot supply "any list of species as the flora of a single and sterile soil". Suggests a possible source of information, and provides some figures for Britain, but these apply to diverse soils.

Sends a count of the number of species of flowering plants and ferns on the islands of Fayal and Flores in the Azores.

Discusses the transport of seeds by birds. William Thompson received letters on this subject from CD in 1848 and from Edward Forbes in 1850. Encloses copies of Thompson’s reply to Forbes’s letter of 23 Feb 1850 and of Thompson’s notes (1848–51) on transport of seeds by birds.

JDH’s "grand speech" on receiving the Royal Medal.

Is Bentham’s list of aberrant genera biased by exclusion of genera with many species?

JDH’s belief that Aquilegia varieties are one species is consistent with their great interfertility.