History of the formulation of cell theory

History of the formulation of cell theory In the history of biology, ancient Greeks were the first who organized the data of natural world. Aristotle presented the idea that all animals and plants are somehow related. Later this idea gave to questions like “is there a fundamental unit of structure shared by all organism?”. But before microscope s were first used in 17th century, no one knew with certainly that living organisms do share a fundamental unit i.e.cell. Cells were first described by a British scientist, Robert Hooke in 1665. He used his self-made light microscope to examine a thin slice of cork. Hooke observed a “honeycomb” of tiny empty compartments. He called the compartments in cork as cellulae. The first living cells were observed a few year later by Dutch naturalist Antonie Van Leeuwenhoek. He observed tiny organism under his microscope and called them as “animalcules”. Robert Hooke For any other century and a half, the general importance of cells was not appreciated by biologists. In 1809, Jean Baptist De-Lamarck proposed that “no body can have life if its parts are not cellular tissues or are not formed by cellular tissues. In 1831, a British botanist Robert Brown discovered nucleus in the cell. In 1838, a German botanist Matthias Schleiden studied plant tissues and made the first statement of cell theory. He stated that all plants are aggregates of individual cells which are fully independent. One year later, a German Zoologist, Theodor Schwann reported that all animal tissues are also composed of individual cells.. Schleiden and Schwann proposed cell theory in its initial form. In 1855 Rudolf Virchow, a German Physician, proposed an important extension of cell theory. He proposed that all living cells arise from pre-existing cells. In 1862, Louis Pasteur provided experimental proof of this idea.