Returns book [W. O. Focke, Pflanzen-Mischlinge]. It was of great use.

Suggests experiment involving light stimulation of plants.

Discusses GJR’s idea of subjecting plants to brief flashes of light.

Hoped to see GJR in London, but was too tired.

Delighted his book Movement in plants has interested GJR.

Asks if GJR has example of dogs calling on each other to go hunting; there is a case half a mile away.

Has heard that Samuel Butler has abused him in his latest book, but he does not intend to look at it.

Glad CD thinks experiment worth trying [see 12904]. Has written to John Tyndall for permission to do it at Royal Institution.

Paper on echinoderms written [with J. C. Ewart, "Locomotor system of Echinodermata", Philos. Trans. R. Soc. Lond. 172 (1881): 829–85].

John Tyndall has provided apparatus for experiment with light.

Frank [Darwin]’s paper a brilliant success [J. Linn. Soc. Lond. (Bot.) 18: 406–19, 420–55. Read 16 Dec].

Has got a monkey for observation.

Comments on papers by Francis Darwin.

Suggests methods for growing seedlings for experiments involving light.

Comments on GJR’s observations on monkey.