-
384 BCE
Aristotle
He articulated principles of generation to account for the theory that developing organisms go through a series of stages before acquiring their final form. -
Zacharias Jansen
Known for inventing the compound optical microscope. It made the cell theory easier and more practical while observing cells. Many would say he is credited for making the first truly compound microscope. -
Jan Baptist van Helmont
Was a Flemish physician, philosopher, music, and chemist who recognized the existence of discrete gasses and identified carbon dioxide. -
Robert Hooke
Discovered saw tiny boxlike cavities, which he illustrated and described as cells. He had discovered plant cells. Hooke's discovery led to the understanding of cells as the smallest units of life, the foundation of cell theory. -
Anton van Leeuwenhoek
Became one of the first scientists to refer to living cells when he observed an abundant number of single-celled organisms, which he called animalcules. He had also observed protozoans through a microscope. -
Lorenz Oken
He asserted that there are fundamental units of life, which he named ‘’infusoria.’’ They were general ideas about the elemental structures of living organisms, anticipated the subsequent identification of the cell and development of it. -
Robert Brown
He discovered the nucleus which helped and contributed to the cell theory. His theory helped confirm the second half of the cell theory. -
Theodor Schwann
He proposed the cell theory according to which all plant and animal tissues recomposed of cells, and within an individual organism all the cells are identical. -
Matthias Schleiden
He defined the cell as the basic unit of plant structure, and a year later Schwann defined the cell as the basic unit of animal structure. -
Albrecht von Roelliker
Discovered that sperm cells and egg cells are also cells. And Humans are born from cells beginning to end. -
Rudolf Virchow
Used the theory that all cells arise from pre-existing cells to lay the groundwork for cellular pathology, or the study of disease at the cellular level. His work made it more clear that diseases occur at this level. His work led to scientists being able to diagnose diseases more accurately. -
Louis Pasteur Jan
He disproved spontaneous generation. He was the first scientist to prove that cells can only form from pre-existing cells. He did this by creating an experiment that showed cells would only grow in broth if air was exposed.
