Contributions to Cell theory

Events

Janssen invents the microscope

1590

Invented the microscope

Robert Hooke

1665

The cell was discovered by Robert Hooke in 1665.

Leeuwenhoek

1674

First to see and describe bacteria.

Schwann

1838

Stated that animals are made up of cells

Schleiden proposed that all plants are composed of cells.

1838

He stated that the different parts of the plant organism are composed of cells. 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.

Pasteur

1850

He was the first scientist to prove that cells can only form from pre-existing cells.

Virchow completes cell theory.

1855

Rudolph Virchow suggested that all cells come from pre-existing cells. He also stated that not all plants are made up of cells,which eventually lead to the creation of the cell theory.