Encloses memorandum on Origin [1866]

discussing mimicry in mammals and birds,

abnormal habits shown by birds,

behaviour of cuckoos,

and analogies existing between mammals of the same geographical region.

Speculates on possible lines of development linking groups of mammals.

[CD’s notes on the verso of the letter are for his reply.]

Thanks CD for a recent letter.

Reports on his health, which has been bad for 12 months.

Sends extracts of works on domestication.

Discusses the pairing of various birds; comments on the pugnacity of partridges, pheasants, male guinea-fowl, and peacocks.

Gives proportions of sexes in pheasants.

Detailed notes on secondary sexual differences in various species of birds and mammals.

Has examined Leschenaultia and concludes the external viscid surfaces have nothing to do with the stigmatic surface. Agrees with CD’s style and nectary conclusions; accounts for their form and position in irregular flowers by describing floral development.

[Enclosed are some queries by CD with answers by JDH. Gives information on seed setting by Mucuna

and an opinion on the abruptness of N. and S. limits of plant ranges.]

Notes several cases of "dioecio-dimorphism" in different genera; feels the discovery of pollen that will act only on the pistil of another flower is most important. Believes CD should next turn his attention to investigating cases of "precocious fertilisation".

John Scott’s paper [see 4332] read at Linnean Society; praised by George Bentham.

Himalayan pine in Macedonia.

JDH is in a quarrel with H. C. Watson.

Gives some observations on orchids and on some plants which seem to be dichogamous.

Discusses sexual and seasonal differences in the plumage of birds and coats of mammals.

Remarks upon variations in the form of the canine tooth between the sexes in mammalian groups.

Plumage of allied species of plover.

Asks CD’s help with work on unimproved domestic animals.

Coloration in moths.

Quotes Achille Guénée on relative proportion of sexes in Phalaenites.

Shot a sandpiper in Norway, the hind toe of which was clasped by a freshwater bivalve.

Sends replies to CD’s queries about sex ratios in humming-birds.

He forwarded CD’s queries on the insane to James Crichton-Browne who has now answered.

Data on good and bad pollen-grain yields of different species. Sends sketches of two male Rhamnus catharticus flowers [see Forms of flowers, p. 294].

Has been looking at separation of sexes in poplars.

Interested in reversion.

Does not understand all CD said on inheritance.

JDH now remembers that Origin was "published" some time before it was "distributed" and therefore appeared prior to his own essay [see also 2478].

Impossible to say whether some Dipterocarpaceae survived a cold period or have developed since.

Queries on expression among Fuegians and Patagonians.

Discusses phases of climate.

Describes fossil mammals discovered by Auguste Bravard in South America.

Has had argument with Bishop of Oxford [Samuel Wilberforce] about CD’s book [Origin].

Discusses review in Annals and Magazine of Natural History. Guesses that T. V. Wollaston is the author.

Discusses evidence of shells on Madeira.

Comments on paper by Wallace ["On the zoological geography of the Malay Archipelago", J. Proc. Linn. Soc. Lond. (Zool.) 4 (1860): 172–84].

Sends address.

Sends CD passages from A. S. Taylor’s book [On poisons in relation to medical jurisprudence and medicine, 2d ed. (1859)], citing smallest portions of poisons that are chemically detectable. "Drosera beats the chemists hollow."

Explains discrepancies in weights and measures caused by changes since 1836 in apothecaries’ measures.

EC has found that a discrepancy in A. W. von Hofmann’s experiments with iodine solutions resulted from an error in Hofmann’s use of decimals.

Reports S. P. Woodward’s opinion of the Origin: "a very sad book, it unsettles all one’s religious principles and the worst of it is so much of it is true".

CD’s divergent series explains those anomalous plants that hover between what would otherwise be two species in a genus.

Inclined to see conifers as a sub-series of dicotyledons that developed in parallel to monocotyledons, but retained cryptogamic characters.

Mentions H. C. Watson’s view of variations.

Man has destroyed more species than he has created varieties.

Variations are centrifugal because the chances are a million to one that identity of form once lost will return.

In the human race, we find no reversion "that would lead us to confound a man with his ancestors".

Argument, based on geographical distribution and competition, for a mundane glacial period rather than cooling of one longitudinal belt at a time.