Thanks for Insectivorous plants.

Believes Lepidoptera are of greater importance as fertilisers in alpine regions than in lowlands.

The famous stone pits of Ohningen are for sale.

Is glad CD is working on cross- and self-fertilisation; reports recent works of botanists, notably Thomas Meehan’s ["Are insects any material aid to plants in fertilisation?", Philadelphia Press 13 Aug 1875], in which the importance of cross-fertilisation is denied.

Observations on hive- and humble-bees. Perforating habits differ in different individuals of the same species.

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.

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.

HM intends studying bees to find evidence supporting CD’s theories. His work has shown him there are problems in separating species from varieties, and has also revealed many surprising instances of variation in habits.

Is preparing a work on fertilisation of flowers, and wants to add a list of works containing observations on cross-fertilisation of plants. Asks CD for any references he may have.

Thanks CD for MS on the routes of male bees.

His "Fertilisation of flowers" is complete [Die Befruchtung der Blumen (1873)].

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

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.

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

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