Rudolf Virchow did not directly contribute to the original formulation of the cell theory. The cell theory, as we know it today, was primarily developed by Matthias Schleiden and Theodor Schwann in the 1830s.

However, Virchow's major contribution to cell theory was his famous dictum, "Omnis cellula e cellula," which means "all cells arise from pre-existing cells." This was a revolutionary idea that built upon the existing cell theory and ultimately expanded it.

Here's how Virchow's work contributed:

* Challenged spontaneous generation: Before Virchow, many believed that living organisms could spontaneously arise from non-living matter. Virchow's discovery disproved this theory by stating that all cells originate from other cells, thereby establishing a continuous lineage of life.

* Foundation for modern biology: Virchow's discovery laid the foundation for modern biology and cell biology. It helped us understand how life is organized and how cells play a fundamental role in the structure and function of living organisms.

* Importance of cell division: His statement emphasized the importance of cell division as the mechanism for growth, development, and reproduction in all living organisms.

While Virchow did not contribute to the initial formulation of the cell theory, his work fundamentally expanded it by clarifying the origin of cells and establishing a crucial principle in cell biology.