Researching on how Hans Jenssen, Zacharias Hooke, Anton Leeuwenhoek, Mathias Schleiden, Theodor Schwann, Rudolf Virchow, and August Weismann contributed to cell theory and the invention of the microscope
Weismann was a theorist and experimentalist and came up with a theory of "germ plasm" which is similar to the theory of evolution. He is said to be the cofounder with Darwin of the theory of natural selection. He had issues with his church in his earlier years so was a great critic of creationism. This is what drove him to pursue to create theories such as natural selection.
Virchow was the founder of pathological processes. Through this, he created a theory in which diseases affect the organs of the body. His theory was that the diseases didn't simply come from the organs themselves but simply in specific cells of the organs.
Through his research, he constructed many theories on botany and wrote a book named Microscopic Investigations on the Accordance in the Structure and Growth of Plants and Animals. Soon his theories became constituted and are the founders of modern day histology.
Leeuwenhoek was the first man to see protozoa, bacteria, and yeast. His microscopes were basically powerful lenses (magnifying glasses) instead of compound microscopes. His microscope was the most state of the art at the time. He made over 500 microscopes but fewer than 10 are used in modern day times.
Robert Hooke was the founder of the Hooke's Microscope. He cut up a sliver of a cork and put it through the microscope. He noticed the cork had pores, "noble juices", and "fibrilous threads". These were mostly only found in living plant organisms which indicated to the cork's origin of being part of a living organism.
Hans and Zacharias Janssen were credited for making the "first microscope" called the optical/refracteoring telescope. Many microscope designed following it were based on or very similar to the design of the Janssen's. http://www.amazines.com/Hans_Lippershey