Robert Hooke's Micrographia of 1665 is an epochal work in the history of scientific representation. With microscopes and other optical devices, Hooke drew and then oversaw the engraving of Micrographia's plates, images that amount to little less than revelations from beneath the range of human vision (Fig. 1). In bristling detail, molds flower into putrid bloom, crystals protrude like warts from mineral skins and, for the first time in history, cells are brought to the eyes of a general viewership. So historical scholarship has shown us, Hooke was especially well equipped to make these wondrous images. A product of Oxford's lively scientific community of the 1650s and a protégé of the chemist Robert Boyle, he possessed intimate knowledge of the "new sciences" of the seventeenth century and a particular gift as an experimentalist. Indeed, from 1662 until nearly the end of his life, Hooke held the post of "Curator of Experiments" to England's premier scientific institution, the then newly-formed Royal Society of London. But, Hooke also had an additional advantage. Following some remarkable, juvenile feats of drawing, he had previously been apprenticed to Peter Lely, leading portrait painter of later seventeenth century England. Combining scientific training with tutelage in the art of portraiture-that most detail-attentive of pictorial genres (at least as practiced in seventeenth century England)-Hooke would seem to have commanded the ideal skills for rendering the sights made perceptible through microscopes. Not surprisingly, Hooke's Micrographia has served as an important point of reference in recent studies of the interactions of art and science.Yet, as the plates and pages of Micrographia attest, Hooke's investigations of nature also made use of representations that were neither pictures nor clearly picture-like. Directly below his elegant rendering of crystals in Micrographia's seventh plate, Hooke presents the viewer with a sequence of eleven incremental combinations of circular forms. So he explains, these diagrams denote not anything seen by a microscope, but patterns of crystalline vegetation he had generated by making groups of spherical "bullets" vibrate together. "If put on an inclining plain, M. Hunter (B)