Infusoria was the term used by early naturalists to describe microscopic organisms because most of their observations were based on ‘infusions’ of water and other substances. Scientific circles used this term until the second half of the 19th century, when the development of cell theory and the simultaneous diffusion of evolutionary theory brought about different 1 Today, the term infusoria is still in use among hobbyists to describe microorganisms cultivated to feed fish and other aquarium animals.and understandings of . Dismissing the early views of microorganisms as miniature animals defended by naturalists like Christian Gottfried Ehrenberg in the , cellularity and the extensive microscopic observations of early scientists provided other terms, like Protozoa and Protista.
This video is part of a series on the microcosmos and introduces infusoria through the fascinating Ehrenberg Collection held at the Museum für Naturkunde Berlin. (Source: Journey to the Microcosmos/YouTube)