The chromosome number in humans: a brief history

Following the rediscovery of Mendel's work in 1900, the field of genetics advanced rapidly. Human genetics, however, lagged behind; this was especially noticeable in cytogenetics, which was already a mature discipline in experimental forms in the 1950s. We did not know the correct human chromosome number in 1955, let alone were we able to detect a chromosomal abnormality. In 1956 a discovery was reported that markedly altered human cytogenetics and genetics. The following is an analysis of that discovery.