Robert Hooke discovered that cork was made up of many tiny boxlike compartments, which he called cells. He made this observation in 1665 with a microscope and published it in Micrographia.

What he actually saw

Hooke was looking at dead cell walls in cork , not living cells with nuclei and organelles. The tiny spaces reminded him of small rooms, so he used the word “cell”.

Why it matters

His discovery was important because it helped launch the study of cells and later became part of the foundation of cell theory.