-
Robert Hooke
further developed the compound microscope, including the use of the iris diaphragm. Hooke kept a detailed record of his observations. -
Anton van Leeuwenhoek
Described unicellular organisms from his observations of a drop of stagnant rainwater as 'animalcules'. -
Leeuwenhoek
Discovered bacteria from his observations of salvia -
Robert Brown
Noted that the cells of orchids he was observing under the microscope contained a structure inside the cell. He called this the 'nucleus'. -
Matthias Schleiden and Theodor Schwann
Formulated the cell theory that all living matter is composed of small units called cells -
Rudolf Virchow
Stated that 'where a cell exists there must have been a pre-existing cell, just as the animal arises only from an animal and the plant only from a plant. -
Ernst Ruska
Built the first electron microscope. Transmission electron microscope. Transmission electron microscopes and scanning electtron microscopes were developed in the following decades. Details of internal cell structures were revealed.