Asks whether he might copy two of FJC’s drawings of Aldrovanda. He would like to have a proof of the plate for two woodcuts to be used in his forthcoming book [Insectivorous plants].

Thanks CD for his letter of 1 Jan 1875. Will send a paper on the genus Volvox ["Die Entwicklungsgeschichte der Gattung Volvox", Cohn Beitr. Biol. Pflanz. 1 (1875) Heft 3: 99–115].

Informs CD of his discoveries of the "house"-building capacity of Difflugia, one of the lowest forms of organism.

Sends CD his writing on Aldrovanda and Utricularia, which he is welcome to use in his forthcoming book [Insectivorous plants].

Has observed a Dionaea fertilised without insect aid.

CD’s publisher is sending FJC an early copy of Insectivorous plants, in which he hopes that FJC’s admirable papers are acknowledged with the respect that they deserve.

Acknowledges presentation copy of Insectivorous plants.

Studying Drosera on vacation in Bohemia. Thinks CD has erred in considering "aggregation" to have occurred in the protoplasm. Suggests it is result of exosmosis of vacuole.

Responds to FJC’s criticism regarding "aggregation" as it occurs in protoplasm [see 10131].

Clarifies his thoughts on "aggregation" in Drosera.

Further discussion of the process of aggregation in response to [10137].