Scientists – Microscopes
1. Anton van Leeuwenhoek
When: mid 1600’s
Discovery: credited with inventing light microscope
– tiny microscope with glass bead
Observations: observed “animalcules” (wee beasties)
in a drop of pond water
2. Robert Hooke
When: 1665
Discovery: Named the cell
Observations:
 Looked at cork under microscope (also spiders,
insects, flowers, etc.)
 Observed that cork was made of empty little
boxes he named cells
3. Robert Brown
When: 1800’s
Discovery: nucleus
Observation: observed objects in the center of cells
4. Matthias Schleiden*
When: 1830’s
Observations: Used microscope to study plant parts
Conclusion:
 All plants made of cells
 Nucleus plays a role in cell reproduction
(expanded on Brown’s observation)
5. Theodor Schwann*
When: 1830’s
Observations: Observed many animals under
microscope
Conclusion:
 All animals are made of cells
 All living things are made of cells
6. Rudolf Virchow*
When: 1850’s
Hypothesis: cells divide to form new cells
Conclusion: every cell comes from a cell that already
exists
* Contributed to the Cell Theory:
1. All living things are made of cells
2. Cells are the smallest units of living things
3. All cells come from preexisting cells by cell
division.