Sends his book [Die Befruchtung der Blumen (1873)]. Hopes CD will publish an opinion of it.

Thanks for CD’s praise of his book [see 8901].

Praises Expression.

Reports on Fritz Müller’s observations of cross- and self-fertilisation. HM will cultivate the two forms [i.e., mainly self-fertilised and mainly cross-fertilised] in the way CD has described.

He continues his observation of wild flowers. Encloses drawing of Viola tricolor with notes on its self-fertility.

Poa annua shows putative evidence of nectar secretion in grasses. He will continue observations as CD requests.

Reports on insects fertilising Viola tricolor and on the fertilisation of the two wild forms [see Cross and self-fertilisation, p. 124 n., 125].

Sends a note on R. Caspary’s observations of Corydalis self-fertilisation [see Cross and self-fertilisation, p. 331].

Has begun his experiments on the self- and cross-fertilised flowers.

Fritz Müller is now working on the Brazilian honey-bees (Melipona and Trigona).

HM thanks CD for fertilisation references.