In the hopes of widening the public’s understanding of naturalism, German biologist Ernst Haeckel published Kunstformen der Natur (or Art Forms in Nature) in 1904. The work, equal parts scientific text and artistic endeavor, highlights Haeckel’s particular interest in the symmetries in living forms. This illustration is from a copy of Kunstformen der Natur in the Case Book Collection in the Prints and Photographs Division of the Library of Congress. The Library holds over 162 million items in almost all media and in more than 470 languages. With subjects ranging from fine art, nature, and architecture to humor, the metaphysical, and more, Pomegranate’s interlocking jigsaw puzzles combine stunning images, superb color reproduction, and sturdy construction to delight generations of novice and veteran puzzle solvers alike.