Image of the Week #102, July 31st, 2013: From: How the Fleas' Next of Kin Ended up Living on a Liverwort in Alaska by Jennifer Frazer at The Artful Amoeba. Source: The Flea, by Robert Hooke. From Micrographia, 1665. Public domain. At first glance, Robert Hooke's illustration of a flea is basic, clean, and straightforward. Under today's standards of 3D computer graphics, we might not even look twice at it. But note the year: 1665! The flea first appeared as an 18-inch engraving in Hooke's classic Micrographia. At the time, no one save a few pioneers of early microscopy had ever seen a small invertebrate magnified. Hooke's flea would have been most people's only acquaintance with the finer details of this common parasite. Seeing this speck of an animal with every hair, every sclerite in enlarged detail must have been a revelation. For more about this image, see here.