Spoke too harshly about CD’s involvement in nomenclatural reform.

JDH used to think CD "too prone to theoretical considerations about species", hence was pleased CD took up a difficult group like barnacles. CD’s theories have progressed but JDH not converted. Sikkim has not cleared up his doubts about CD’s doctrines.

Argument with Falconer.

Falconer’s misbehaviour.

Geology of Khashia [Khasi] mountains. Speculations on mountain building and origin of Himalayas.

Wants catalogue of small islands that contain peculiar plants. Thinks complete floras of islands in various stages of depression [subsidence] would provide good data.

James Wilson reports case of salmon hybrids.

Herrings inhabit freshwater lake in Scotland during winter.

JDH will edit juror reports for the Great Exhibition.

Flora of New Zealand.

Reconsidering variability of insular species.

Becoming convinced of the probability that the southern flora is a fragmentary one – all that remains of a great southern continent.

Royal Society votes its Royal Medal for 1853 to CD. JDH reports the debate and vote at the Royal Society Council.

Honoured for Coral reefs

and Cirripedia.

List of most anomalous Leguminosae [from George Bentham].

Is relieved his book [Himalayan journals] has been well received and glad he has successfully completed it.

JDH summarises letter from Humboldt.

JDH answers CD’s questions on glacial action in Himalayas.

Birth of JDH’s second child.

Asks CD’s view of "highness" and "lowness" in animals. Gives his own for plants; extent of deviation from type, e.g., floral parts deviating from leaf.

Reading B. C. Brodie’s Psychological inquiries [1854].

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.

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].

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.

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.

Bentham’s list of aberrant genera: CD’s worry that he eliminated large genera a priori is half right. He eliminated those large, anomalous genera that virtually constitute natural orders. JDH criticises CD’s tabulations of aberrants.

Difficulty of distinguishing affinity and analogy in plants.

JDH not happy with CD’s explanation of the absence of north temperate forms in the Southern Hemisphere, given his explanation for the spread of sub-arctic forms to the south. [CD’s note is in response to JDH’s criticism.]

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?

CD’s tabulation of colonists curious but explicable.

Working on Tasmanian flora; contemplating general essay on Australian distribution: Tasmania and Australia same alpine species; Swan River flora very peculiar and quite distinct from New South Wales.

Trying to establish new journal at Linnean.

JDH criticises C. J. F. Bunbury’s paper on Madeira [J. Linn. Soc. Lond. (Bot.) 1 (1857): 1–35].

Absence of Ophrys on Madeira suggests to JDH a sequence in creation of groups.

Why are flightless insects common in desert?

Australian endemism.

Finds Forbes’s continental theories, migration, and double creation are all unsatisfactory explanations of geographical distribution of plants.

Is currently working on problems of sea transport of plant species.

European plants on Australian Alps only explicable by double creations.