After Canadian anatomist Murray Llewellyn Barr, people found Barr body, also called sex chromatin, the condensed, inactive X chromosome, in the nuclei of somatic cells of most female mammals.
https://en.wikipedia.org/wiki/Murray_... After Canadian anatomist Murray Llewellyn Barr, people found Barr body, also called sex chromatin, the condensed, inactive X chromosome, in the nuclei of somatic cells of most female mammals.