Development of Cell Theory

Spontaneous Generation

300

Aristotle
Aristotle said that there was no difference between living and nonliving things. This started the idea of spontaneous generation.

First Microscope Invented

Nov 6, 1595

Link to Jansen
Jansen invented the first compound microscope which allowed people to see cells.

Mice Recipe

Jan 1, 1600

[Jan Baptista van Helmont](www.britinnica.com/EBcheck/topic/101517/cell-theory)Around 1600, Jan Baptista van Helmont came up with the recipe for rice which was dirty clothes+wheat+21 days=mice. This added to the idea of Spontaneous Generation.

Cells Found

Jan 1, 1665

Robert Hooke
In 1665, Robert was the first to observe cells by looking at a piece of cork through a microscope. He also gave cells their name.

Bacteria and Protozoa

Jan 1, 1670

Anton van Leeuwenhoek
Around 1670, Leeuwenhoek observed bacteria and protozans. It showed that there are microorganisms.

All Livng Things Are Made of Cells

Jan 1, 1800

[Lorenz Oken](www.britinnica.com/EBcheck/topic/101517/cell-theory)
Around 1800, Oken suggested that all living things are made of cells.

Nuclei

Jan 1, 1831

Robert Brown
Robert Brown discovered nuclei in both animal and plant cells.

Parts of Plants Made of Cells

Jan 1, 1838

Mathias Schleiden
Mathias found that parts of plants were made of cells. He was one of the founders of the Cell Theory.

Plants Are Made of Cells

Jan 1, 1839

Theodor SchwannIn 1839, Theodor Schwann recognized nuclear structures in animal cells that he had also seen in plant cells earlier. He then added to cell theory that all plkants are made of cells.

Tissue

Jan 1, 1848

Albrecht von Roeliker
In 1848, Albert observed tissue of an organism.

All Cells Can Reproduce

Jan 1, 1850

Rudolf Virchow
He added to cell theory that all cells can reproduce.

Spontaneous Generation is Wrong

Jan 1, 1859

Louis Pasteur
Around 1859, Louis did an experiment proving spontaneous generation wrong by boiling beef broth in a snannet flask.