When Antonie van Leeuwenhoek read Robert Hooke's book about cells he was interested and built his own microscope, going on to grind far more advanced lenses. He also discovered Bacteria while examining the teeth of old men who had never brushed their teeth.
In 1665 Robert Hooke published a book called "Microphagia" he had drawings of what he saw in a microscope while observing slices of cork.
He was inspired by Schleiden's work and he looked at animal tissue, proving that animals are made up of cells as well. He also discovered that each cell has a nucleus.
He conducted experiments that showed that cells reproduce. These findings are take the place of the old theory that cells are created through "spontaneous generation"
He looked at plant tissue and found that cells are what make up plants and that plants grow by making new cells.