Cell Discovery By cutefroggy Jan 1, 1590 Microscope Invention Jan 1, 1665 Robert Hooke sees cells the first time Jan 1, 1673 Leeuwenhoke found bacteria Jan 1, 1831 Robert Brown found that nucleus was important Jan 1, 1838 Mathhias Schleinden concluded that all plants have cells Jan 1, 1889 Theodor Schwann concluded that all animals have cells