Francesco Redi demonstrated that the presence of maggots in putrefying meat does not result from spontaneous generation but from eggs laid on the meat by flies.
Antoine van Leeuwenhoek was the first to observe bacteria and protozoa
Abraham Trembley was the first to witness regeneration by cell division in algae
Caspar Wolff demonstrated that organs are formed in differentiated layers from undifferentiated cells
Henri Dutrochet discovered osmosis and the importance of green pigment in the use of carbon dioxide by plant cells; also came to the conclusion all living things are made of cells