Jan Swammerdam

Jan Swammerdam
A 19th-century fantasy portrait, based on the face of Hartman Hartmanzoon from Rembrandt's The Anatomy Lesson of Dr. Nicolaes Tulp. No genuine portrait is known.
Born	(1637-02-12)February 12, 1637 Amsterdam, Dutch Republic
Died	February 17, 1680(1680-02-17) (aged 43) Amsterdam, Dutch Republic
Nationality	Dutch
Alma mater	University of Leiden
Known for	Describing erythrocytes, work on entomology
Scientific career
Fields	Entomology

Jan or Johannes Swammerdam (February 12, 1637 – February 17, 1680) was a Dutch biologist and microscopist. His work on insects demonstrated that the various phases during the life of an insect—egg, larva, pupa, and adult—are different forms of the same animal. As part of his anatomical research, he carried out experiments on muscle contraction. In 1658, he was the first to observe and describe red blood cells. He was one of the first people to use the microscope in dissections, and his techniques remained useful for hundreds of years.