The naturalist and his lithographer

In June 1911, Ernst Haeckel received a newspaper clipping that gave his recently deceased lithographer an honorary doctorate. The notice called Adolf Giltsch “Dr. phil. h. c.” Haeckel had to correct it. No university faculty had awarded Giltsch the degree, although Haeckel thought he deserved one.

Students in Jena had been calling him Doctor Giltsch for years. They had learnt microscopic observation and drawing from him, and the title had stuck. Haeckel could only guess that a grateful pupil had supplied the newspaper with its information.

Giltsch worked in a family printing business in this German university town. Haeckel was a zoologist and an advocate of Darwin's theory of evolution. Between 1899 and 1904, their collaboration produced the hundred plates of Kunstformen der Natur—Art Forms of Nature. Jellyfish, microscopic shells, orchids and hummingbirds became printed arrangements of spirals, branches, chambers and wings. Haeckel's name stood on the title page. In the preface, he thanked Giltsch for the artistic execution of the figures and their lithography, praising his understanding of animal form as well as his artistic ability.

Learning the object

Their working relationship grew out of a smaller enterprise. When Haeckel arrived at Jena in 1861, he found Eduard Giltsch employed in a little print shop. Eduard had been a caretaker at the botanical garden. According to Haeckel's later account, he had worked his way into printing without substantial formal preparation or resources, then taught his son Adolf the trade at fourteen.

The father and son supplied plates for the scientific journal that Jena's medical and natural history society began publishing in 1864. They also printed Haeckel's evolutionary family trees and illustrated his biological studies. The work joined two kinds of judgement: a naturalist's decisions about what a structure meant, and a draughtsman's decisions about how another person could see it.

Haeckel described the difficulty rather frankly in his obituary. Authors sometimes supplied inadequate sketches and badly drawn figures. Giltsch wanted to understand the object before deciding on its outlines and shading. Haeckel credited him with investigating external shape and internal structure, then using that knowledge to make the image. His own hand drawings, he acknowledged, had often been corrected and improved by Giltsch.

The scale of their work increased with the reports of HMS Challenger, the British expedition that sampled the oceans in 1872–1876. Haeckel undertook the study of several groups of organisms. In 1911, he remembered twelve years of work with Giltsch, from 1877 to 1889, and their examination of radiolarian preparations made by the expedition's naturalist John Murray. Across their entire collaboration, he reckoned, Giltsch had drawn and lithographed more than four hundred large plates for him, besides smaller ones.

A shell named for Anna

One of the organisms in Haeckel's 1887 radiolarian report was Dictyocodon annasethe. Radiolarians are single-celled marine organisms; this one's rigid silica framework looked like a small, elaborate vessel. Its three main chambers together measured only 0.22 millimetres. The largest was about 0.12 millimetres across. A microscope was needed to resolve its construction.

The description separated its parts carefully. A long horn rose above the small upper chamber. Three triangular lattice wings projected from the next section. The lower chamber carried three bands of large openings, divided by finer mesh, and ended in nine triangular feet. These were the features another observer would need to recognise, rather than simply the outline of an attractive miniature.

Haeckel dedicated the species to Anna Sethe, his first wife. They had married in 1862; she died in 1864. By the time the radiolarian appeared in Kunstformen der Natur, its name had already carried that dedication for years. It occupied figure 10 on Plate 31, in the centre of the bottom row.

The popular book gave such forms a different setting. In his preface of February 1899, Haeckel complained that many beautiful natural structures remained hidden in expensive scientific publications, beyond the reach of a wider public. He wanted artists and people interested in nature to have access to them. His proposed first series contained fifty plates, issued in groups of ten. If it found enough readers, he would extend it to a hundred.

He had a large stock of earlier work to draw on. He also said explicitly that he would select suitable forms from the scientific literature. The book assembled knowledge accumulated across publications, observations and other people's material. Each finished page needed a new composition.

Wellcome Collection's account of the production describes the exchange between the two men. Haeckel supplied sketches based on his research notes. Giltsch developed professional drawings; Haeckel made amendments; Giltsch then drew the resolved images on lithographic stone for printing. A published plate had passed through several opportunities for a line, a proportion or a relationship to be reconsidered.

Making a comparison

The two published versions of D. annasethe differ visibly. The earlier figure has an uneven outline and a horn that bends away from a straight central axis. In the later version, the horn stands much straighter and the wings correspond more closely on either side. Its mesh has become an orderly pattern across a balanced silhouette.

Marine scientist John Dolan placed the figures together in a study published in 2019. He argued that the later drawing's near-perfect symmetry showed aesthetic preferences taking precedence over accuracy in at least some of the book's illustrations. The earlier image is itself a scientific drawing, rather than a photograph of an untouched specimen, but it provides a particular comparison against which the later regularity can be judged.

The change cannot be assigned confidently to one man's hand. Haeckel selected and reviewed the material; Giltsch drew it for reproduction and was capable of correcting it. Their documented working arrangement allowed both to intervene, but no surviving instruction for this particular alteration has been established.

Other choices were openly stated. The eleven figures on Plate 31 were enlarged at different magnifications, from two hundred to six hundred times. A large form on the page was not necessarily a larger organism in the sea. Haeckel was arranging a comparison of shells with different numbers of chambers and different horns, wings and feet. The grouping could be read across a sheet; it did not reproduce a single view down a microscope.

Nor were all eleven pictures equivalent representations of living cells. Haeckel's text explained that the plate principally showed their silica skeletons. Only the large central figure, Calocyclas monumentum, also included the soft living body and its radiating threads. The structure named for Anna was a shell. Its open lattice should not be mistaken for a complete account of the organism that made it.

Haeckel's own claim for the book was exacting. He said that he had confined himself to faithful representations of existing natural forms, leaving decorative adaptation to the artists who might use them. Yet selection, orientation and enlargement already shaped what a reader encountered. In figure 10, the repeated openings and paired wings had become more regular as well. The pictured structure was recognisable, but the two editions offered different degrees of tidiness.

The names on the page

Anna's memorial had neighbours. To its left, Stichophaena Ritteriana honoured Paul von Ritter, whose foundation supported evolutionary zoology at Jena. Haeckel thanked him in the preface for help with the wider undertaking. The supporter of the work appeared again inside its classification.

Another shell, Alacorys Bismarckii, was named for Otto von Bismarck, the statesman central to the creation of the German Empire. Haeckel compared its five strong feet to the columns of a monument. His accompanying tribute praised Bismarck as the empire's founder and celebrated its colonial power. These personal and political tributes accompanied the technical descriptions of chambers, horns and latticework.

Giltsch's contribution was acknowledged differently, in the preface and in the working relationships behind the plates. Haeckel said the hundred illustrations could not have been made without him. He also recalled the commercial choice the lithographer had faced as his reputation spread and commissions accumulated.

Publishers had encouraged Giltsch to enlarge his business into a major lithographic establishment. Haeckel thought he might have become rich. In the account he left, Giltsch preferred a medium-sized concern and the personal freedom it allowed him. He stayed with his existing business. When he died in June 1911, two sons were taking it over.