Asks CD to write a letter sponsoring him for the Chair of Comparative Physiology at Paris. There are some who do not think his work on artificial production of monstrosities belongs in physiology.

Thanks CGE for memoir on the Bacillariae of Mexico [Abh. K. Akad. Wiss. Berlin (Phys.) (1869): 1–66].

Council of the Society of Arts has decided to form a committee to watch the interests of telegraphy. Invites JH to become a member.

Inquires about the mathematical nature of the chords of music, offering some ideas of his own.

Will learn with regret that Feldhausen has had to be sold because R. J. Jones, the owner, was in debt. Outlines the alterations to the house and to the neighborhood now that the railroad has appeared. Has a tribe of grandchildren now.

Thanks CD for his orchid paper ["Fertilization of orchids", Collected papers 2: 138–56]. Comments briefly on orchids.

Discusses moths in which the wing underside is the most brightly coloured, and relates his observations on sexual selection by a moth, Syntomis.