Thanks for his article on musical scales. Will read it later when he has time. Comments on the system of equal temperament. Will send some of his own papers later.

Congratulates CD on success at Cambridge [of George Darwin].

Would like CD to study the anomalous Cardamine pratensis.

Suggests THF write a paper on violets. Asa Gray, once a sceptic, now declares he is convinced whole structure of a flower is adapted for a cross with another individual.

Urges THF not to give up Pangenesis lightly. "It has thrown light on my mind in regard [to] a great series of complex phenomena."

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.

Information on proportion of sexes born in sheep.

No summary available.

Hopes that JH will contribute series of papers under heading, 'A Life's Retrospect in Science,' from various periods of JH's career, for publication in Good Words.

Thanks for verses on the transit of Mercury; comments on observation of an auroral arch and eclipse observations of the solar corona.

Relates some observations on the expression of elephants; they do not cry unless the eye is hurt or struck. "Perhaps Mr Darwin will like to know the above."

Beginning of extract from William Dell Hartman’s "Journal of the doings of Cic[ada?] septemdecim" [unidentified] in Pennsylvania in 1851.

Writes on various observations and discoveries on dimorphic and trimorphic plants.

Thanks SN for the reference about the reindeer, received via Hooker.

CD wishes to ascertain whether there is any relation between the period of development of a character and its transmission to one sex alone.

Thanks BDW for extracts about "drumming" [of male Cicada to attract females].

Asa Gray and Hooker doubt that 13–year and 17–year Cicada forms should be considered distinct species. CD is inclined to agree with them.

Suggests observations be made of ratio of females to males in the rarer form.