Walther Flemming (born April 211843 in Sachsenberg, Germany; died August 41905 in Kiel) was a founder of the study of cytogenetics.
Flemming trained in medicine at the University of Rostock, graduating in 1868. Making use of aniline dyes he was able to find threadlike structures in the cell nucleus— the chromosomes. Flemming investigated the process of cell division and the splitting of chromosomes into identical halves. He called this process mitosis from the Greek word for thread. These results were published in 1882.