Red blood cells

Red blood cells first seen in blood w/ microscope. Due to improvements in microscopes in 1650s, Swammerdam studied insects. Father of modern entomology (study of insects).
 Jan Swammerdam Netherlands 1658 Red blood cells

Red blood cells first seen in blood w/ microscope. Due to improvements in microscopes in 1650s, Swammerdam studied insects. Father of modern entomology (study of insects).