Evolution of cell theory By 830103464 1500 Creation of the microscope By Zacharias Janssen 1600 Beginning of the study of cells Robert Hooke 1839 First cell theory Matthias Schleiden, Theodor Schwan and Rodolf Virchow 1850 Changes in microscopes By Carl Zeiss 1880 Biogenic Law By August Weissman 1920 Creation of the electron microscope Hans Buch, Dennis Gabor