Sets out some of his ideas on the effects of disuse on an organ. Disuse as a cause of reduction.

Thanks GJR for his letter, regrets pressure of other work prevents his giving GJR’s remarks the attention they deserve. GJR makes clearer how an organ that has started to decrease will go on decreasing.

Encloses a copy of a letter from H. Spencer giving his opinion on GJR’s views on disuse and a draft of GJR’s reply to Spencer.

Sends MS notes on intercrossing.

Describes different reactions of rabbits and guinea-pigs to stinging nettles.

Has made a number of grafts at Kew.

Encloses notes on natural selection; discussion of factors mitigating the swamping influence of intercrossing on incipient variations.

Responds to MS of Earthworms. An objective but arbitrary test of intelligence in animals is the ability to learn from experience. Earthworms fall on the border of intelligence. They could justly be called intelligent if they could learn by experience to manipulate some unknown, exotic leaf. CD should make clear that intelligence does not imply self-consciousness.

Accepts GJR’s offer to prepare sugar-cane paper for publication [Villa Franca and Glass, "New varieties of sugar-cane", Proc. Linn. Soc. Lond. (1880–2): 30–1]. Suggests introduction and outline.

Agrees with GJR on microscope for Grant Allen.