Who modified cell theory?

Cell theory:

1. Cell theory is a scientific theory, which says that living organisms are made up of cells, that they are the basic structural/organizational unit of all organisms and that all cells come from pre-existing cells.
2. The cell theory was first given by Theodore Schwann in 1839..
3. The first part states that all organisms are made of cells.
4. The second part states that cells are the basic unit of life.

Modification:

1. Rudolf Virchow modified the hypothesis of cell theory given by Schwann and Schleiden.
2. He stated that new cells arise from pre existing cells.