He has never observed the straight line flight routes in male humble-bees that CD reports.

His last letter was in error: alpine Bombus terrestris does break into some flowers.

Thanks for Cross and self-fertilisation.

Fritz Müller has been appointed "Naturalista Viajante" of the Rio de Janeiro Museum, which will help his income greatly.

No papers on heterostyly have appeared since 1873.

Thanks CD for calling attention to a "considerable error" in his observations on Hottonia fertility [in Die Befruchtung der Blumen (1873)]. [See Forms of flowers, p. 52.]

Is pleased that CD agrees with HM’s suggestions and criticisms of CD’s work. Will undertake experiments with Viola tricolor seeds to see if they produce both large- and small-flowered plants.

Reports results of crosses between the two forms of Viola tricolor: 1. Female small flower crossed with male large flower yields all small flowers (cleistogamous self-fertilisation suspected); 2. Male small flower crossed with female large yields intermediate flowers; 3. Large flower crossed with large flower yields self-sterility symptoms.

Thanks CD for his efforts to get HM’s book, Die Befruchtung der Blumen [1873], translated into English. [See Fertilisation of flowers, translated by D’Arcy W. Thompson, preface by C. Darwin (1883).]

Will soon return to his observations on insects in general and bees in particular.

Seventieth birthday greetings.

HM’s teaching methods and his ideas are under attack in Germany along with the works of Ernst Krause.

Fritz Müller’s daughter has committed suicide.

HM’s son will visit CD when he comes to London.

Is glad CD approves of his judgment of G. Bonnier’s paper on nectaries [Gaston Bonnier, "Les nectaires", Ann. Sci. Nat. (Bot.) 8 (1879): 5–212].

Movement in plants has shown him CD’s research method: 1. Find a fundamental idea of great generality (circumnutation); 2. Pursue it everywhere with observations and experiment; 3. Conduct special observations which undo any doubt of generality.

Fritz Müller suffered moderate damage in Brazilian flood.

Continued praise for the universal importance for botany of Movement in plants.

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.

Thanks CD for his photograph.

Intends to start experimenting with mosses to determine which differences in structure are effected by altered conditions of life.

HM is certain his brother Fritz would like to see Für Darwin translated into English by Dallas. He will make arrangements with the German publisher.

Two friends are writing Darwinian works: Adolf Speyer on phylogeny of Lepidoptera

and August Röse on genealogy of mosses.

Has heard from W. Engelmann of Leipzig; he is willing to let CD have the woodcuts to Fritz Müller’s work [Für Darwin (1864)] for 22 thalers.

Thanks CD for the English edition of his brother’s book [Fritz Müller, Facts and arguments for Darwin (1869)]

and for CD’s memoir on orchids ["Fertilization of orchids", Collected papers 2: 138–56].