Human civilization had a good understanding of how sex and reproduction worked long before the microscope was invented. But it wasn't until the 17th century that anyone knew what sperm actually were, or were aware of their strange appearance. And when sperm finally were formally discovered, by Antonie Philips van Leeuwenhoek, the father of microbiology, he was so uncomfortable he wished he could unsee what he'd just observed.
When Royal Society Secretary Henry Oldenburg asked Leeuwenhoek to look at semen, the Dutch draper initially did not reply "because he felt it was 'unseemly.'"
