Discovery of the Cell
It was not until the mid-1600s that scientists began to use microscopes to observe living things. In 1665, Englishman Robert Hooke used an early compound microscope to look at a thin slice of cork, a plant material. Under the microscope, cork seemed to be made of thousands of tiny, empty chambers which he called "cells" because they reminded him of a monastery's tiny rooms which were at the time called cells.
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Using a microscope similar to the one shown to the right, Hooke made this drawing of cork cells. In Hooke's drawings, the cell look like empty chambers because he was looking at dead plant matter. Today, we know that living cells are made up of many structures. |
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Around the same time in Holland, Anton van Leeuwenhoek, who is considered the "father of microscopy," used a single-lens microscope to observe pond water and other things. To his amazement, the microscope revealed a fantastic world of tiny living organisms that seemed to be everywhere, even in the water he drank.
United Streaming Video Clip: Anton van Leeuwenhoek
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The Cell Theory
Following Hooke and van Leeuwenhoek's discoveries of cells, numerous observations made it clear that cells were the basic units of life:
- 1838 - Matthias Schleiden concludes that all plants were made of cells.
- 1839 - Theodor Schwann concludes that all animals are made of cells.
- 1855 - Rudolph Virchow proposes that all cells come from existing cells.
These discoveries, confirmed by other biologists, are summarized in the cell theory, a fundamental concept of biology. The cell theory states:
- All living things are composed of cells.
- Cells are the basic units of structure and function in living things.
- New cells are produced from existing cells.
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This site was last updated on Saturday, November 22, 2008.
