The always wonderful BibliOdyssey site has posted some amazing 19th century drawings from pioneering microscopist Christian Gottfried Ehrenberg, as well as a few from Ernst Haeckel (a second set here). The images are part of the archives at the Humboldt University Museum für Naturkunde.

Apart from their obvious aesthetic value, as a former member of an imaging lab works like these always make me stop and consider the current state of imaging tools, and our ability to communicate our results to one another. While these days it seems fairly trivial to publish a movie of GFP expression in a C. elegans embryo, or of Xenopus gastrulation, imagine having to painstakingly draw the detailed structures seen below. Then imagine having the talent to draw them as beautifully as Ehrenberg or Haeckel. While there are obvious advantages to recording events in three dimensions over time, it does comparatively make one feel like something of a button-pusher (link via BoingBoing).