Hans and Zacharias Janssen

• Dutch lens grinders, father and son
• produced first compound microscope (2 lenses)

Robert Hooke (1665)

• English scientist
• looked at a thin slice of cork (oak cork) through a compound microscope
• observed tiny, hollow, roomlike structures
• called these structures 'cells' because they reminded him of the rooms that monks lived in
• only saw the outer walls (cell walls) because cork cells are not alive

Anton van Leeuwenhoek (around the same time as Hooke 1680?)

• Dutch fabric merchant and amateur scientist
• looked at blood, rainwater, scrapings from teeth through a simple microscope (1 lens)
• observed living cells; called some 'animalcules'
• some of the small 'animalcules' are now called bacteria

Matthias Schleiden (1838)

• German botanist
• viewed plant parts under a microscope
• discovered that plant parts are made of cells

Theodor Schwann (1839)

• German zoologist
• viewed animal parts under a microscope
• discovered that animal parts are made of cells

Rudolph Virchow (1855)

• German physician
• stated that all living cells come only from other living cells