1. Robert Hooke was the first person to discover the existence of cells with the help of a microscope in 1665.
2. Leeuwenhoek, in 1674, with the improved microscope, discovered free-living cells in pond water for the first time.
3. Robert Hooke, when joined as a scientist in Royal society for scientists was given a project to invent the microscope and study the insects.
4. Hooke constructed a microscope for himself and studied all the materials like blood, urine, trees, leaves, glass etc. He discovered small spaces while cutting a cork. He called them as cells. Cell meaning ' a little room'. He found these cells in a dead cork.
5. Later Leeuwenhoek in 1674 discovered so many organisms in a drop of water. He observed them under a microscope constructed by himself. This led to the discovery of living cells.