Leeuwenhoek, Antony van (änˈtōnē vän lāˈvənhōkˌ) [key], 1632–1723, Dutch student of natural history and maker of microscopes, b. Delft. His use of lenses in examining cloth as a draper's apprentice probably led to his interest in lens making. He assembled over 247 microscopes, some of which magnified objects 270 times. In the course of his examination of innumerable microorganisms and tissue samples, he gave the first complete descriptions of the bacteria, the protozoans (which he called animalcules), spermatozoa, and striped muscle. He also observed the red blood cells in his detailed study of capillary circulation. He was elected to the Royal Society of England in recognition of his work.
See his collected letters (Vol. I–VI, 1939–61).