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.].

Thanks for the information about the male plumage. [See 5374.] Will look to the papers in Ibis to which AN has referred him. He finds AN’s theory captivating.

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".

On final instalment of "Insular floras" [Gard. Chron. (1867): 75]; rejoices at extent of their agreement.

Some criticisms of JDH’s position on geographical affinities, and volcanic islands.

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.

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 the Duke of Argyll and a review of his Reign of law.

Asa Gray’s theological view of variation. God’s role in formation of organisms; JDH’s view of Providence.

Insular and continental genera.

Owen on continuity and ideal types

and on bones of Mauritius deer.

On man.

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.

Thanks WT for information.

Will not include chapter on man in Variation but plans separate essay in future.

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.

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

Sends a copy [missing] of a lecture by L. Agassiz on glaciers.

Claims worker wasps can generate additional workers in the absence of the fertile female.