Description of Protozoa

Date: October 9, 1676 • Location: London, United Kingdom

Antonie van Leeuwenhoek wrote a letter to the Royal Society describing "animalcules" – the first known description of protozoa (pictured).

Antonie Philips van Leeuwenhoek was a Dutch microbiologist and microscopist in the Golden Age of Dutch art, science and technology. A largely self-taught man in science, he is commonly known as "the Father of Microbiology", and one of the first microscopists and microbiologists. Van Leeuwenhoek is best known for his pioneering work in microscopy and for his contributions toward the establishment of microbiology as a scientific discipline.