Question: Who said all living things are composed of cells?
Disambiguated questions and answers: question: Who said all living things are composed of cells, credited with the cell theory?
Who said all living things are composed of cells, contributing to the cell theory?
answer: Matthias Jakob Schleiden
Matthias Schleiden
Schwann
Theodor Schwann
Matthias Schleiden and Theodor Schwann
Schleiden
Virchow
Rudolf Ludwig Carl Virchow
Rudolf Virchow
Natural Questions answer: Matthias Schleiden
Theodor Schwann (from the Wikipedia article "Cell theory")