Transformism explains rudimentary organs, and teratology, which are otherwise inexplicable.

Looking forward to publication of Descent

and CD’s expected book on "Variation in nature" [see Variation 1: 4].

Describes his brother Alexander’s discovery of male of Bonellia, a striking example of dimorphism. Encloses a plate with notes on his brother’s work.

The difficulty his wife, Sofya Kovalevsky, has had as a woman in being admitted to Berlin University. Kirchow [Gustav Robert Kirchhoff], at Heidelberg, has taken an interest in her.

On the expression of disagreeable surprise.

CD was good enough to send notice of his new book [Descent] for the first number of the Academy; asks for further contributions and suggestions.

Experiments with Lapageria.

Does not give much for botanical results of Round Island, but the zoology is wonderful.

Lyell’s new book [The student’s elements of geology (1870)]. Urges Lyell to make it Elementary principles.

Grove is disgusted with CD for being disquieted by William Thomson: "Take another dose of Huxley’s penultimate address to Geol. Soc." [Q. J. Geol. Soc. Lond. 25 (1869): 28–53].

Will not be returning to London for a week; writes to save CD’s calling.

HM intends studying bees to find evidence supporting CD’s theories. His work has shown him there are problems in separating species from varieties, and has also revealed many surprising instances of variation in habits.

Thanks CD for copy of Origin.

Encloses extensive, but incomplete, notes on expression among the insane, dealing specifically with blushing and the actions of the platysma and grief muscles.

Interim report on the experiments with rabbits [to test Pangenesis].

Is currently at work on the development in birds of organs of flight according to CD’s principles; asks permission to quote CD in stating the theory.

Urges CD to republish his works in a collected edition, to make them more readily available to Germans.

Experiments are not going well, but the quantity of blood transfused was small.

Explains that law of inertia, and most of modern mechanics, is all wrong. Explains his concept of "elasticity" of bodies. Applies it to physiology.

Describes the unusual appearance of a horse whose mother had previously borne a foal by a quagga. The effect of one mating on the subsequent pregnancy of another mating is explained by JJW using Pangenesis.

Variety in rabbits less than he hoped for; will try a new mode of transfusion.

Pleased to have encouraged CD to look at Kant.

His observations on mimicry in butterflies

and self-sterility in plants.

Describes crying in an infant.

He and Milne-Edwards are nominating CD for the Académie Française.

Sending book [Charles Darwin et ses précurseurs Français (1870)].

Despite their differences of opinion, expresses his respect and admiration.

Better news about the rabbits.