Contributions to Cell Theory
He contributed to cell theory. He made microscopes and was the first to study single celled organisms. He called them animalcules.
He also discovered bacteria, free-living, parasites, microscopic protests, sperm cells, blood cells, microscopic nematodes, rotifers, and much more.
Date of Contributions
He did this in 1674, over a span of 50 years till 1724.
He was an unlikely scientist; he had no fortune and received no high education. He knew no languages other then Dutch.