-
330 BCE
Aristotle
Aristotle developed the theory that organisms go through a series or stages before acquiring their final form, later called epigenesis. -
Zacharias Jansen
Zacharias Janssen Is known for inventing the compound optical microscope, made in the 1590s. This contributed to Cell theory by making it easier and more efficient while observing cells. He declared that the cell was the building block of all pant matter. His invention helped lead to the rejection of spontaneous generation because his device helped scientists look at the cells of different organisms. -
Jan Baptist van Helmont
In the 1600s Jan Baptist Van Helmont contributed to cell theory by making an important contributed to photosynthesis, that plants get food from soil to be proven wrong. He accepted the ideas of spontaneous generation but insisted that knowledge of the natural world could only be obtained by experiment. -
Robert Hooke
While observing cork thorough a microscope, Hooke saw tiny boxlike cavities, which later came to be plant cells. Hooke's discovery led to the understanding of cells as the smallest units of life. Spontaneous generation was rejected because he could see that the microorganisms were made up from cells, and they didn't come from human flesh or dirt like some people believed. -
Anton van Leeuwenhoek
Anton Van Leeuwenhoek discovered plant anatomy and became an expert on animal reproduction. He also discovered blood cells and microscopic nematodes. Leeuwenhoek’s research on the growth of fleas, mussels, and eels helped disprove the theory of spontaneous generation. -
Lorenz Oken
In 1805, Lorenz Oken stated that "All living organisms originate from and consist of cells" and that “World and organisms are one in kind, and do not stand merely in harmony with each other.” -
Robert Brown
Robert Brown discovered the nucleus and its role helped put together cell theory, that all living organisms are composed of cells, and cells come from pre-existing cells. Browns discovery helped confirm the second half of cell theory -
Matthias Schledien
In 1838, Matthias Jacob Schledien discovered the cell as the basic unit of plant structure and a year later the basic unit of animal structure. Spontaneous generation was later disproved because All organisms are made up of one or more cells. Cells arise from other cells through cellular division. -
Theodor Schwann
In 1839 Schwann discovered that all tissues are made up of cells, which laid the foundations for the cell theory. He also worked on fermentation and discovered the enzyme pepsin. Schwann's cells are named after him. His experiment led to the rejection of spontaneous generation because he discovered that maggots did not appear in the meat unless flies were present. -
Rudolf Virchow
Rudolf Virchow used the theory that all cells arise from pre-existing cells to create groundwork for cellular pathology, or the study of disease at the cellular level. His work led to the scientist being able to diagnose the disease more accurately. The idea of spontaneous generation was rejected in pathology. -
Louis Pasteur
Louis Pasteur invented the swan neck flask to create an environment known not to grow microorganisms. He did this by creating an experiment that showed the cell would only grow in broth if air was exposed. Microorganisms grew only in the controls, refuting spontaneous generation.
