Theodor schwann and matthias schleiden were major contributors to the cell theory as we know it. in 1839 schwann published a book including a summary of his observations into three conclusions about cells: 1. the cell is the unit of structure, physiology, and organization in living things. 2. the cell retains a dual existence as a distinct entity and a building block in the construction of organisms. 3. cells form by free-cell formation, similar to the formation of crystals (spontaneous generation). which one of schwann's statements is no longer accepted as truth? a) cells are found in both living and nonliving entities. b) cells are distinct identities, not just building blocks. c) cells form via free cell formation from existing cells only. d) cells come from pre-existing cells, not from free cell formation.