<Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (December 2009) (Learn how and when to remove this template message) </Td> </Tr> <P> Animalcule ("little animal", from Latin animal + the diminutive suffix - culum) is an older term for a microscopic animal or protozoan . The concept appears to have been understood at least as early as c. 30 BC, as evidenced by the following translation from Marcus Varro's Rerum Rusticarum Libri Tres . </P> <P> "Like precautions must be taken against swampy places for the same reasons and particularly because as they dry, swamps breed certain animalculae which cannot be seen with the eyes and which we breathe through the nose and mouth into the body where they cause grave maladies ." </P> <P> Some better - known animalcules include: </P>

Who invented the microscope and the word animalcule