Hermann Henking

Hermann Paul August Otto Henking (16 June 1858 – 28 April 1942) was a cytologist who discovered the X chromosome in 1890 or 1891. The work was the result of a study in Leipzig of the testicles of the firebug (Pyrrhocoris) during which Henking noticed that one chromosome did not take part in meiosis. He named this X element because its strange behaviour made him unsure whether it was genuinely a chromosome. It later became X chromosome after it was established that it was indeed a chromosome.