Enumerates fossil mammals known in Secondary strata.
Lack of angiosperm plants in rocks older than Chalk is no reason to anticipate rarity of warm-blooded quadrupeds.
CD will advise W. F. Daniell on collecting.
Asks THH question on flow of glaciers after ice has been fractured and fragmented.
CD had to leave Royal Society lecture [joint paper by THH and J. Tyndall, "On the structure and motions of glaciers", Philos. Trans. R. Soc. Lond. 147 (1857): 327–46] before the end because of headache.
CD will advise Daniell not to apply for Royal Society grant.
CD’s experiment: fish fed seeds, which germinated when voided.
Sends specimens of Tortrix, which illustrate the extraordinary variation of markings in two or three species. In every family of Lepidoptera there seem to be species extremely prone to vary and in some localities they vary more than in others.
Thanks THH for his response on glacial movement. Hopes Tyndall will experiment on broken ice and explain how two pieces of ice can freeze together.
Sorry to hear of THH’s row with Richard Owen.
CD is "as ignorant of mechanics as a pig", but glaciers have interested him greatly. Hopes to hear that JT’s experiments with ice will explain the freezing together of ice below the freezing point.
The variations of Peronea caused A. H. Haworth and J. F. Stephens to create 30 or 40 species based on colour and markings. HD was first to be convinced these would be reduced to two.
Discusses species that closely resemble one another;
cites species that differ in variation in different localities;
in some double-brooded species the broods differ markedly in size and colour.
Encloses his list of varieties of Peronea.
Would welcome eggs of any rumpless fowl so that he can investigate how early in development rudimentary organs are rudimentary.
Has not noticed much difference between skeletons of ducks.
Sympathises with Brent’s legal difficulties. Declines offer of a cock silk fowl, but accepts offer of a German old fashioned pouter pigeon.
Birth of his sixth son [C. W. Darwin]. It is dreadful "to think of all the sendings to school and the professions afterwards".
CD is not well but has not the courage for water-cure again; trying mineral acids.
Working hard on the book [Natural selection]; is overwhelmed with riches in facts and interested in way facts fall into groups.
To his surprise [Helix pomatia] has withstood 14 days in salt water.
Pigeons’ skins come in from all parts of the world.
Discusses a proposed expedition to Australia. Urges collecting and investigating productions of isolated islands. Recommends dredging the sea-bottom.
Mentions keeping Helix pomatia alive in sea-water.
CD is sending two pairs of Persian fowl, from Hon. C. Murray.
Thanks WBT for various offers: a drake, a young silk fowl, a rumpless chick.
The German pouters are not old-fashioned ones but fancy birds, probably crosses since they do not breed true.
Sends information on the speed at which his pigeons fly various distances.
Discusses the ranges of alpine species in U. S. and considers the possible migration routes of such species from Europe.
Lists those U. S. genera which he considers protean and describes the U. S. character of some genera which are protean in Europe.
Describes how he distinguishes introduced and aboriginal stocks of the same species.
Has some fowls from Sir James Brooke, which WBT might like to display at Zoological Society.
Sends news of his family, Sulivan, and FitzRoy.
Helix pomatia is quite healthy after 20 days’ submersion in salt water.
On peas, the evidence is on WDF’s side, but CD cannot see how they can avoid being crossed.
He is working hard, wishes he "could set less value on the bauble fame"; would work as hard, but with less gusto, if he knew his book would be published forever anonymously.
Sends cheque for subscription [£20].
The species of Mollusca at Mauritius are almost all different from those of surrounding islands, which confirms the belief that the islands were elevated from the ocean rather than separated from the continent by volcanic action.
