In the 1800s, Germany was very much the leader of the development of new concepts in biology. Ernst Haeckel was an active component of that scientific community. Haeckel, however, is probably best remembered for his art – particularly his beautiful illustrations of plankton – notably the medusa, siphonophores and his great love the radiolarians. He influenced the art of his times and continues to do so. His classic work Kunst-Formen der Natur (published over the period 1899–1904) is still used in art schools as a source book. This work, however, contains a mere 39 images of the full set of 342 images of plankton that Haeckel and his illustrator – Adolf Giltsch – jointly produced. The remaining images are spread through three other works: Der Radiolarien (1862), System der Medusen (1879) and three of the volumes of the reports of the HMS Challenger expedition (Volumes 4, 18, 38, published 1887, 1888, 1889).
Good quality facsimiles of Kunst-Formen der Natur and Der Radiolarien have been published by Prestel (Der Radiolarien, as Art Forms from the Ocean) and, if one is prepared to spend time hunting, copies of the other sets of images can be found on the internet. However, they are commonly of poor quality having been made by scanning thick volumes resulting in severe shading in the area of the gutter; they are also characteristically of low resolution. Copies of System der Medusen (1879) and Challenger Reports can be found in a small number of libraries, but they are held in rare book collections so their use for study and teaching is severely limited – in effect they are a lost treasure.