| Zacharias Janssen | first compound microscope |
| Antonie van Leevwenhoek | made a simple microscope with a glass bead |
| Robert Hooke | discovered box-like structures in cork, called them cells |
| Matthias Schleiden | said that all plants are made of cells |
| Theodor Schwann | said that all animals are made of cells |
| Rudolph Virchow | said every cell comes from a cell that already existed |