CELL THEORY : 1. Matthias Schleiden, a German botanist observed that all plants are composed of different kinds of cells which form the tissues of the plant. 2. Theodore Schwann (1839), a British Zoologist, studied different types of animal cells and reported that cells had a thin outer layer (‘plasma membrane’). 3. Theodore Schwann also concluded that the presence of cell wall is a unique character of the plant cells. 4. Schwann proposed the hypothesis that the bodies of animals and plants are composed of cells and products of cells. Regarding 1,2,3 and 4:
