Snip from a post on the superb BibliOdyssey blog:
One of the sweetly sad pleasures of casually trawling the history of science literature is discovering works and characters of incredible depth and diversity that are not widely known. One of these prolific and brilliant pioneers is Christian Gottfried Ehrenberg who might otherwise be described as a microscopist extraordinaire.
He released 2 great monographs which basically divide between the living and non-living worlds examined under magnification during the 19th century. I have previously posted about the non-living: the microgeological and fossil samples Ehrenberg assiduously examined and recorded that gave rise to a new field within paleontology.
The wonderfully alien images above (and in the following post) come from his earlier 1838 treatise, 'Die Infusionsthierchen als Vollkomene Organismen', in which he identified a large number of unicellular organisms, particularly from the protist diatoms, and chief among them the radiolarians.