His view of CD’s hypothesis that Atlantic island genera are descended from extinct European plants.

Suggests that, in some birds, plumage of males is less colourful than that of females; the reason is that the males perform the duties of incubation [see Descent 2: 204 n.].

Position as Curator allows no time for experiment.

Describes plans for vast new layout of Calcutta Botanic Garden according to natural orders.

Himalayan and Scottish plants are doing well.

Hopes to experiment on temperate plants in tropics, to test CD’s views of migration during glacial periods.

Sends observations on acclimatisation of English cultivated plants.

Leersia CD sent are growing and fertile.

Describes progress in preparation of third German edition of the Origin. Asks about use of photograph for edition.

Encloses letter written a week ago. Letter and enclosure speculate on origins of human races in relation to geological and political changes, according to a theory of progressive development.

Was sorry CD wrote so little on man in Origin.

JM will publish [Variation] "coute qui coute", paying CD half the profits.

Thinks he can count on 500 purchases of what he calls the "Pièces Justificatives" of the Origin and will print 750 copies.

His literary friend found it "difficult of digestion".

First portion of Variation MS has been set up. Murray will not decide on number to be printed until he has read a good portion. The agreement applies only to the first edition.

Wants to know whether Variation is published and how the other book [CD’s proposed volume on variation in nature] is going.

Replies to Queries on expression based on observations of the Kaffir and Fingoe tribes in South Africa.

Thanks for CD’s letter inquiring about capsules produced by the Maxillaria with larger pods [see 5331]. Gives descriptions of Maxillaria and of the other Vandeae.

Describes Oncidium flexuosum.

Tells of botanical results of recent excursion to the German colony Theresopolis. Brought home fine collection of living orchids.

Has declined Presidency of BAAS.

Relation of insular and continental genera will always be difficult problem.

On Providence and the "continuity theory".

Thanks CD for Lythrum paper [Collected papers 2: 106–31] and "Climbing plants" sent to Manchester Ladies’ Literary Society. Comments on Lythrum.

Asks CD whether he has given any thought to the phenomena of spiritualism.

On muscles in man for moving skin, hair, ears, etc.

Sends CD an English translation of his preface to the revised German edition of Origin and asks his opinion of it.

Asks CD where he might get a specimen of Eozoon.

Relieved that CD approves his declining the Presidency of BAAS. The BAAS and the role of scientific men in it.

H. T. Stainton should be elected F.R.S.

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.]

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.

Protective role of colours in caterpillars and butterflies. Sexual differences in colours of butterflies.