The only mainland vegetation he saw on Falkland Island shores were trees. Remembers no strange birds there, but on journey home saw a woodcock more than 500 miles from the nearest land.
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].
Reports that he sees the oxlip, cowslip, and primrose as really distinct species; hybrids are formed between any two.
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.
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.
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.
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.
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.
Hybrid varieties of pheasant and common fowl. Reply to CD queries.
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.]
CD has suggested an explanation of how pike were introduced to a remote lake in Ireland by cormorants [carrying pike spawn on their feet or in their gullets].
Gives instances of sexual differences in the number of tarsi within species of Coleoptera and also variation in the number of tarsi between related species.
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?
Discusses the similarity in size, shape, and structure of the blood corpuscles of the Aves. Notes differences between the corpuscles of the domestic dog and some wild species.