spermatozoa. In 1841 the Swiss anatomist Albert von Kölliker wrote about spermatozoon in his work Untersuchungen über die Bedeutung der Samenfäden (Studies on the importance of spermatozoa). See also Aneuploidy Non-disjunction References External links Slower conception 'leads to boys' Human Sperm Under a Microscope Germ cells Semen Human cells Fertility Men's health Microscopic discoveries by Antonie van Leeuwenhoek