Has little information about hens with spurs. Encloses information from Robert Oettel and C. F. Friderich, and from J. F. Blumenbach’s Vergleichende Anatomie [1805]. Recommends various German publications.

Sending a photograph of a solar prominence he has received from Major J. F. Tennant. Comments on various features. At the Transit of Mercury he saw the phenomenon described by J. H. Schröter.

Intends publishing a second edition of his paper on the Great Pyramid entitled 'Papers and Correspondence on the Pyramid.' Will respect JH's wishes on any points.

Requests permission to include extract from Prelim. Discourse in The Sixth English Reading Book.

Thinks CD’s views of insect agency and crossing might explain structure and variations of papilionaceous flowers. Lists five points. Asks CD’s opinion.

No summary available.

Appreciates JH's beautiful simplification of the numerals in musical arithmetic. Wishes JH would give up the point of the variability of the supertonic and transfer it to the submediant. Agrees with JH over the need for a keyboard instrument possessing a perfect chromatic scale in any particular key.

Thanks to WH for the photograph of solar protruberances; comments on polarization of light from the sun.

Reports his observations of the nebula around Eta Argus. Provides a sketch. Has observed fifty other nebulae.

Comments on glaciers in North America.

Asks if glacial periods have occurred alternately in the Northern and Southern Hemispheres. Relevant to his glacial discoveries in South America: "it would have been an immense relief to my mind if I could have assumed … this". CD wishes to discuss subject in new edition of Origin [5th].

On H. C. Watson’s false and contemptuous criticism of [J. D. Hooker and T. Thomson] Flora Indica [1855].

W. B. Carpenter’s deep-sea dredgings.

James Croll’s last paper ["On geological time", Philos. Mag. 35 (1868): 363; 36 (1868): 141, 362].

Thanks for information on fowls.

Glad to see extracts from Blumenbach about sexual differences in fowls.

Seems to JH to be some systematic error in some of RM's observations; JH includes examples.

Comments on experience of being a father.

Discusses possible English edition of Generelle Morphologie. Mentions necessary revisions.

Thanks CD for comment on Natürliche Schöpfungsgeschichte.

Discusses problem of assigning specific times to origin of classes.

Advises THF that best plan is to investigate the part certain structures play with all plants or orders, instead of describing means of fertilisation in particular plants. Naturalists value observations far more than reasoning.

CD thought Watson’s article beastly in its criticisms of JDH. Watson’s criticism of CD was not new or important, but fair, so CD could honestly thank him, adding his regret at what was said about JDH.

Is sitting for Woolner bust.

Has read James Croll on alternation of glacial and warmer periods in north and south, which would remove JDH’s objections to cool period extending to equator.

Anxious to hear how the Lubbocks take the disastrous termination to their hopes. [Sir John Lubbock was defeated in the Parliamentary election on 25 Nov 1868.]

JL’s failure to be elected to Parliament.

Thanks JP for congratulations on success of George Darwin at Cambridge.

Does not have time to investigate propagation of Cardamine.

Thanks for paper on action of solar and electric light on vapors, which should give JT further insight into blue color of sky and polarization of skylight. Comments on the latter. JH's son [Alexander] is working hard at Glasgow.