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1582
Zacharias Janssen
Zacharias Janssen is credited to have made one of the earliest compound microscopes. It could magnify up to 20-30x the normal size. -
Robert Hooke
Robert Hooke published a book filled with drawings and descriptions of the organisms he had viewed under the microscope. He had discovered that there were small structures that made up a cork when looking at it under a microscope. These box-like structures reminded him of rooms in monasteries and he, therefore, called them cells. -
Anthony Van Leeuwenhoek
Anthony Van Leeuwenhoek was most likely the first person to observe blood cells and sperm cells. He also made observations on single-cell organisms which he called “little animalcules”. -
Anthony Van Leeuwenhoek
Leeuwenhoek observed protozoa, the first single celled organism. He also created his own lenses for the microscope. -
Henri Milne-Edwards
Henri Milne-Edwards determined that all animal tissues were formed from globules -
Robert Brown
Robert Brown recognised the presence of a nucleus in plant cells through his research. Brown published his research findings and gave speeches. His discovery of the nucleus and its role helped to put together the cell theory, which states that all living organisms are composed of cells, and cells come from pre-existing cells. -
Matthias Schleiden
Matthias Schleiden defined that the basic unit of the plant structure was the cell. The first part of the cell theory states that all organisms are made of cells. The second part states that cells are the basic units of life. These parts were based on a conclusion made by Schwann and Matthias Schleiden in 1838, after comparing their observations of plant and animal cells. -
Theodor Schwann
Theodor Schwann and Matthias Schleiden articulated the cell theory using their observations. -
Rudolph Virchow
In 1855 Virchow published a statement based on his observations Omnis cellula e cellula, which means that all cells arise from pre-existing cells. -
Louis Pasteur
Louis Pasteur contributed to the cell theory in 1859 when he provided evidence against the idea of spontaneous generation (i.e., living matters can spontaneously arise out of non-living matters). In this case, the spontaneous generation proposed that air could cause the existence of living organisms