Cell-tastic Cell Theory Timeline

Hans and Zacharias Janssen

1590

Zacharias Janssen along with his father, Hans Janssen, created a compound microscope. However, Zacharias Janssen was the main contributor to the microscope. This microscope gave many scientists the opportunity to observe organisms under large magnification amounts. Using this microscope, they can discover new facts about cells and living things.

Robert Hooke

1665

Robert Hooke created a more advanced model of a compound microscope to use. By using slices of cork, he observed tiny compartments in the cork that were honeycomb shaped. Robert Hooke called these pores “cells” because they looked like small rooms, or cells, for monks in monasteries. Although he did observe where cells were, they weren’t living because cork isn’t living bark. However, he still contributed to the cell theory by discovering that cells exist in living things.

Francesco Redi

1668

This scientist performed an experiment with meat and flies. After observing the flies’ interactions with meat, he found that they actually laid eggs on it. This disproved spontaneous generation, because it showed that organisms actually do come from something other than the earth, like eggs. This also supports that all cells come from only preexisting cells.

Anton van Leeuwenhoek

1674

Anton van Leeuwenhoek was the first scientist to observe active and living cells through bacteria and Protozoa. He observed these cells through the collection of pond water and other types of water. Anton van Leeuwenhoek named these findings ‘animalcules’ because they looked like very tiny animals. In 1677, this scientists became the first person to look at spermatozoa, or sperm cells as well.

Robert Brown

1831

This Scottish botanist observed many moving pieces in plant cells which are now known as organelles. Also, after observing orchids Robert Brown discovered that plant cells have nuclei. This helped discover more about cell structure.

Matthias Schleiden

1838

This German botanist observed plant cells under microscopes to learn more about their structure. Through many of his observations, Matthias Schleiden concluded that all plants and their many parts are made up of cells or their derivatives. This helped to confirm part of the cell theory that says every organism is made up of one or more cells.

Theodor Schwann

1839

This German physiologist constantly examined animal tissue. From these examinations, he concluded that all animals are built from cells. This supports the cell theory by validating that all organisms are made up of one or more cells.

Alexander Carl Heinrich Braun

1845

Alexander Carl Heinrich Braun added to the cell theory by concluding that cells are the basic unit of all life. This supports the second tenet of the cell theory, stating that cells are the basic unit of structure and function in all living things.

Rudolph Virchow

1855

Rudolph Virchow published the famous statement of his, “omnis cellula e cellula.” This means that all cells come from preexisting cells, which is one of the tenets of the cell theory. Without Rudolph Virchow’s aphorism, the cell theory wouldn’t be complete.

Walther Flemming

1879

This German anatomist used various dyes to examine cells. During this experiment, he discovered that the cells began to divide. He then created slides from this experiment that showed the nucleus at different points through the process of cell division. Walther Flemming called this process mitosis, and showed that all cells come from preexisting cells.