Cell Theory Timeline

  • Jan 1, 1538

    Andreas Vesalius

    Andreas Vesalius
    He created detailed illustrations of anatomy for students in the form of six large woodcut anatomical posters. In 1539 he also published his Venesection letter, on bloodletting.
  • Hans and Zacharias Janssen

    Hans and Zacharias Janssen
    Zacharias and Hans Janssen contributed to the modern cell theory by inventing the first telescope. They invented the single-lens microscope in 1595 by placing several lenses in a tube. They were trying to find a way to make magnification even greater so as to help people with seriously poor eyesight.
  • Nnton Van Leeuwenhoek

    Nnton Van Leeuwenhoek
    Leeuwenhoek main discoveries:
    the infusoria in 1674
    the bacteria in 1676.
    the vacuole of the cell.
    the spermatozoa in 1677.
    the banded pattern of muscular fibers, in 1682.
  • Robert Hooke

    Robert Hooke
    In 1665 Hooke published Micrographia, a book describing observations made with microscopes and telescopes, as well as some original work in biology. Hooke coined the term cell for describing biological organisms, the term being suggested by the resemblance of plant cells to monks' cells. The hand-crafted, leather and gold-tooled microscope he used to make the observations for Micrographia, originally constructed by Christopher White in London.
  • Francesco Redi

    Francesco Redi
    Redi is most well known for his series of experiments, published in 1668 as Esperienze Intorno alla Generazione degl'Insetti (Experiments on the Generation of Insects), which is regarded as his masterpiece and a milestone in the history of modern science. The book is one of the first steps in refuting "spontaneous generation" - a theory also known as Aristotelian abiogenesis. At the time, prevailing wisdom was that maggots arose spontaneously from rotting meat.
  • John Needham

    John Needham
    He was first exposed to natural philosophy while in seminary school and later published a paper which, while the subject was mostly about geology, described the mechanics of pollen and won recognition in the botany community.
  • Lazzaro Spallanzani

    Lazzaro Spallanzani
    Spallanzani was a Catholic who researched in 1768 the theory of the spontaneous generation of microbes. At the time, the microscope was already available to researchers, and using it, the proponents of the theory, Buffon and Needham, came to the conclusion that there is a life-generating force inherent to certain kinds of inorganic matter that causes living microbes to create themselves.
  • Lorenz Oken

    Lorenz Oken
    In the Grundriss der Naturphilosophie of 1802 Oken sketched the outlines of the scheme he afterwards devoted himself to perfecting. The position advanced in that work, to which he continued to adhere, is that "the animal classes are virtually nothing else than a representation of the sense-organs, and that they must be arranged in accordance with them." Consequently, Oken contended that there are only five animal classes
    1.Dermatozoa 2.Glossozoa 3.Rhinozoa 4.Otozoa 5.Ophthalmozoa
  • Jean-Baptiste Lamarck

    Jean-Baptiste Lamarck
    Lamarck referred to a tendency for organisms to become more complex, moving 'up' a ladder of progress. He referred to this phenomenon as Le pouvoir de la vie or la force qui tend sans cesse à composer l'organisation (The force that perpetually tends to make order).
    The second component of Lamarck's theory of evolution was the adaptation of organisms to their environment. This could move organisms upward from the ladder of progress into new and distinct forms with local adaptations.
  • Robert Brown

    Robert Brown
    In 1827, while examining grains of pollen of the plant Clarkia pulchella suspended in water under a microscope, Brown observed minute particles, now known to be amyloplasts (starch organelles) and spherosomes (lipid organelles), ejected from the pollen grains, executing a continuous jittery motion. He then observed the same motion in particles of inorganic matter, enabling him to rule out the hypothesis that the effect was life-related.
  • Theodor Schwann

    Theodor Schwann
    In 1837, Matthias Jakob Schleiden found that all plants are composed of cells, and communicated the finding to Schwann, who had found similar structures in the cells of the notochord, as shown earlier by Müller. Other researchers confirmed the similarity, as explained in Schwann's Microscopic Investigations on the Accordance in the Structure and Growth of Plants and Animals, where he concluded, "All living things are composed of cells and cell products"
  • Matthias Jakob Schleiden

    Matthias Jakob Schleiden
    He stated that the different parts of the plant organism are composed of cells. Thus, Schleiden and Schwann became the first to formulate what was then an informal belief as a principle of biology equal in importance to the atomic theory of chemistry. He also recognized the importance of the cell nucleus, discovered in 1831 by the Scottish botanist Robert Brown, and sensed its connection with cell division.
  • Louis Pasteur

    Louis Pasteur
    In Pasteur's early work as a chemist, he resolved a problem concerning the nature of tartaric acid (1848). A solution of this compound derived from living things (specifically, wine lees) rotated the plane of polarization of light passing through it. The mystery was that tartaric acid derived by chemical synthesis had no such effect, even though its chemical reactions were identical and its elemental composition was the same.
  • Rudolf Carl Virchow

    Rudolf Carl Virchow
    His most widely known scientific contribution is his cell theory, which built on the work of Theodor Schwann. He is cited as the first to recognize leukemia cells. He was one of the first to accept the work of Robert Remak, who showed the origins of cells was the division of pre-existing cells. He did not initially accept the evidence for cell division, believing it only occurs in certain types of cells.
  • Santiago Ramón y Cajal

    Santiago Ramón y Cajal
    This provided definitive evidence for what would later be known as "neuron doctrine", now widely considered the foundation of modern neuroscience. In debating neural network theories. Ramón y Cajal was a fierce defender of the neuron theory.
    He provided detailed descriptions of cell types associated with neural structures, and produced excellent depictions of structures and their connectivity.
    He discovered a new type of cell, to be named after him: the interstitial cell of Cajal.
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