A historic photomicrograph of a parasite (Trichomonas vaginalis).

Knowing that Alfred Donné was the discoverer of an important human parasite, and finding that he was also a pioneer of photomicrography, it occurred to me that his parasite might well have become a subject of his photography. It was a simple matter to confirm that this was indeed the case. The parasite he discovered was Trichomonas vaginalis; and, in collaboration with Foucault, Donné made a photomicrograph showing several protozoan parasites lying among vaginal epithelial cells. His publication of an engraved image of the photomicrograph in 1845, was a landmark in the history of photography and microbiology.