This Day in History: 1730-03-11

Otto Friedrich Müller (1730 – 1784) was born on this day. He was a Danish naturalist and a pioneer in the study of micro-organisms. Müller discovered the first diatom ever seen but thought it was an animal because of its movement.
He arranged the Infusoria for the first time into genera and species in Vermium Terrestrium et Fluviatilium, seu Animalium Infusoriorum, Helminthecorum, et Testaceorum non Marinorum, succincta Historia (2 vol 1773 – 74). Hydrachnæ in Aquis Daniæ Palustribus detectæ et descriptæ (1781), and Entomostraca (1785), describe many species of previously unknown microorganisms coining the terms bacillum and spirillum; Cuvier praised his work, giving him, “a place in the first rank of those naturalists who have enriched science with original observations.”

Müller described a number of taxa of microorganisms and is honoured in the names of species under muelleri and ottomulleriana.