Zacharias Jansen created the first microscope, which led to the development and continuation of microscopes. He combined two convex lenses within a tube. His invention started the journey to the makings of the cell theory.
Robert Hooke discovered the cell in 1665 when he viewed a thin cork cutting and saw pores. He figured out how many cells were in a cubic inch, and studied pants and ideas about cells. Without Hooke, cells may not have been discovered for hundreds of years. He wrote a book called Micrographia, which held the first documented information on microscopes. His contributions helped scientists learn more about how cells work.
Anton van Leeuwenhoek built and improved microscopes. In 1674, he first discovered bacteria which was an amazing discovery. He discovered what he called, "animalcules", in a pond water sample. He made sketches of his findings, which included pond organisms, bacteria, and blood cells. Once he discovered bacteria, scientists knew much more about the concept of cells.
Theodor Schwann found out that all animals were composed of cells, and started the beginnings of the cell theory. He believed that all living things are composed of cells and cell products. He also said that the cell was the most basic unit of a living organism.
Schleiden found out that all plants were made of cells. He realized the importance of the nucleus and knew its connection to cell division. He also proposed the cell theory with Schwann. In addition, he believed that all living things are composed of cells.
Rudolph Virchow suggested that all cells come from previous cells, and that not all plants were composed of cells. He showed how the cell theory also applied to bodily functions and diseases, and summarized the cell theory with the Latin phrase, "Omnis cellula a cellula".