Cell Theory Timeline By Kingdedad10 1590 The first microscope was invented 1663 Robert Hooke discovered cells 1674 Leeuwenhoek discovered animalcules 1838 Schleiden concluded that all plants have cells 1839 Schwann concluded the same conclusion about animals 1855 Virchow concluded that all cells come from other cells 1930 Scientists developed several types of electron microscopes
