Kunstformen der Natur

Kunstformen der Natur (known in English as Art Forms in Nature) is a book of lithographic and halftone prints by German biologist Ernst Haeckel.

Originally published in sets of ten between 1899 and 1904 and collectively in two volumes in 1904, it consists of 100 prints of various organisms, many of which were first described by Haeckel himself. Over the course of his career, over 1000 prints were produced based on Haeckel's sketches and watercolors; many of the best of these were chosen for Kunstformen der Natur, translated from sketch to print by lithographer Adolf Giltsch.

Harvard hosts an excellent app for viewing the drawings

via John Overholt