Anton Van Leeuwenhoek’s invention of the microscope in 1675 provided scientists with an instrument, which opened up a whole new world for them. While examining pieces of cork under the newly developed microscope, Robert Hooke, an English scientist, observed very distinct empty spaces. He named these little box like structures “cells” and even though Hooke was observing a non-living structure, the term evolved to describe living things. Leeuwenhoek continued to observe everything he possibly could - blood, rainwater, and even scrapings form his teeth. “He called the living things ‘animalcules’. Today they are known as bacteria”(1). The discovery of these single celled organisms fascinated Leeuwenhoek and eventually led to the development of more specialized microscopes.
Observations of microorganisms continued. In 1824 Dutrochet, a Frenchman, observed many different plants and animals and suggested, ”various parts of organisms are composed of cells”(2). This work was followed by Robert Brown, a Scottish scientist who in 1831 announced the central part of the cell is called the nucleus and by Dujardin, another Frenchman, whose discovery in 1835 enlightened scientists to the fact that cells are not hollow but are in fact filled with a thick, jellylike fluid.
Research continued by Matthew Schleiden in 1838 and Theodor Schwann in 1839. After observing plant and animal cells they concluded all plants and animals are composed of cells which are alive and which contribute to the total operation of the organism of which it is a part of. Rudolph Virchow confirmed their findings and in 1858 “he stated that all cells come from other living cells. The works of these scientists led to the formation of the cell theory which states that all living things are made of cells; cells are the basic units of structure and function and living cells come from other living cells” (3). This persistence, curiosity and observations laid the groundwork for future cellular research.