The Origin converted him from a Linnean interpretation of flowers and mosses.

Glad that CD appreciates his continuing work on mosses, in support of natural selection.

Plans to repeat CD’s orchid experiments.

Sends interpretation of the floral anatomy of Lopezia miniata.

Thanks for "Climbing plants" offprint and for references on fertilisation of flowers.

Considering the bounty of work already done, he is looking for something original to do.

Subularia does not grow in Westphalia.

Thanks for German version of Origin [1867].

Dipterous insects are adapted to eating pollen rather than only to sucking nectar. He describes such adaptations in two dipteran species.