He offered no interpretations, but simply the facts of what he had found, accompanied by exquisite drawings. He sent reports on almost everything that could be usefully examined—bread mold, a bee's stinger, blood cells, teeth, hair, his own saliva, excrement, and semen (these last with fretful apologies for their unsavory nature)—nearly all of which had never been seen microscopically before.
After he reported finding "animalcules" in a sample of pepper water in 1676, the members of the Royal Society spent a year with the best devices English technology could produce searching for the "little animals" before finally getting the magnification right. What Leeuwenhoek had found were protozoa. He calculated that there were 8,280,000 of these tiny beings in a single drop of water—more than the number of people in Holland. The world teemed with life in ways and numbers that no one had previously suspected.
Inspired by Leeuwenhoek's fantastic findings, others began to peer into microscopes with such keenness that they sometimes found things that weren't in fact there. One respected Dutch observer, Nicolaus Hartsoecker, was convinced he saw "tiny preformed men" in sperm cells. He called the little beings "homunculi" and for some time many people believed that all humans—indeed, all creatures—were simply vastly inflated versions of tiny but complete precursor beings.