Bombus mastrucatus, an alpine bee, conforms to his observations that B. terrestris breaks open the flowers of Trifolium pratense. However, in the Alps, B. terrestris does not behave this way.

Gentiana species are adapted to lepidopteran cross-fertilisation.

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.

Thanks HM for his review [of Forms of flowers, Kosmos 2 (1877–8): 286].

Thinks HM’s previous article was very important [Kosmos 2 (1877–8): 128–40]. CD will "heartily rejoice" if HM has explained the steps by which Rhamnus and Valeriana have been rendered dioecious.

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.

Writing on vegetable physiology.

Nothing in CD’s life has ever interested him more than the fertilisation of such plants as Primula and Lythrum.

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.

Has just heard that HM has been treated shamefully by his Government. What has happened?

Seventieth birthday greetings.

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