Ernst Haeckel’s present of the first two volumes of Das Antlitz der Erde by Eduard Suess to his friend Dr. Paul von Ritter: Why is it important?

On 12th July 1890, the noted biologist Ernst Haeckel and his friend Dr. Paul von Ritter took a field trip south and east of Jena with a view to discussing plans for the future of a professorship for geology and palaeontology and checking some ideas that had come to their minds whilst reading Eduard Suess’ Das Antlitz der Erde (The Face of the Earth). This excursion had not been recorded elsewhere except in a letter to Haeckel from von Ritter written on 17th July 1890 and we would not have known about it had Haeckel not given as a present the first two volumes (all those published till then), of the Antlitz to von Ritter and described the itinerary of their joint excursion in some detail in the autograph dedication (not contained in von Ritter’s letter). Here we speculate on the driving motive for this excursion, which was part of the celebrations in July 1890 for Paul von Ritter, who, in 1886, had donated the great gift of 300,000 Marks to the university to support Haeckel’s research. We conclude that this was a truly interdisciplinary undertaking in which university politics about the founding of a second Ritter Chair of geology and palaeontology, in addition to the chair of phylogeny already established, probably played an important role, even though it was not established until 1894. The geological part was clearly inspired by Suess’ second volume of the Antlitz. The central geological problem may have been sea-level fluctuations and extinctions in the biosphere. We also emphasise the importance for the history of science of generally insignificant-looking dedications by important scientists on books they gave others, or received, as presents. We did a thorough search in the Ernst Haeckel Archive in Jena to see whether there are any other traces of this excursion but unfortunately could not find any except the letter mentioned above. Therefore, the autograph presentation in Suess’ book remains the only record of any detail of the excursion of the 12th July and, as such, constitutes an important addition to the biographies of Ernst Haeckel and Paul von Ritter.