History of cell theory

By Travis Bagby

Cell theory

Cell theory refers to the idea that cells are the basic unit of structure in every living thing. Development of this theory during the mid 17th century was made possible by advances in microscopy. This theory is one of the foundations of biology. The theory says that new cells are formed by other existing cells, and that the cell is a fundamental unit of structure, function and organization in all living organisms.


The cell was discovered by Robert Hooke in 1665. He examined very thin slices of cork and saw a multitude of tiny pores that he remarked looked like the walled compartments a monk would live in. Because of this association, Hooke called them cells, the name they still bear. However, Hooke did not know their real structure or function.

The Scientists That Played a Part

Matthias Schleiden and Theodore Schwann

Credit for developing cell theory is usually given to three scientists: Theodore Schwann, Matthias Jakob Schleiden and Rudolph Virchow. In 1839, Schwann and Schleiden suggested that cells were the basic unit of life. Their theory accepted the first two tenets of modern cell theory (see next section, below). However, the cell theory of Schleiden differed from modern cell theory in that it proposed a method of spontaneous crystallization that he called "free cell formation". In fact, Schleiden's theory of free cell formation was refuted in the 1850s by Robert Remark,Rudolf Virchow and Albert Kolliker. In 1855, Rudolf Virchow concluded that all cells come from pre-existing cells, thus completing the classical cell theory. (Note that the idea that all cells come from pre-existing cells had in fact already been proposed by Robert Remak; it has been suggested that Virchow plagiarized Remak.)