History of Cell Theory

Spontaneous Generation

• For 2000 years: life happens (maggots, mice in rags, snow geese).
• Redi (Italy 1668): maggots are fly larvae.
• Spallanzani (Italy 18^th century): sealed flask of broth doesn't grow microbes.
• Pasteur (France 1862): swan-necked flask doesn't grow microbes.

What Technology Hast Wrought

• Robert Hooke (England 1665): describes and names cells.
• Anton van Leeuwenhoek (Netherlands 17^th century): discovers microbes.
• Matthais Schleiden and Theodor Schwann (Germany 1839): all organisms made of cells.
• Rudolf Virchow (Germany 1858): all cells come from cells.

Modern Cell theory

1. Cells are basic unit of life.
2. All organisms are made of cells.
3. Cells come from cells.