““Morgan had discovered an important modification to Mendel's laws. Genes did not travel separately; instead, they moved in packs. Packets of information were themselves packaged-into chromosomes, and ultimately in cells. But the discovery had a more important consequence: conceptually, Morgan had not just linked genes; he had linked two disciplines-cell biology and genetics. The gene was not a "purely theoretical unit." It was a material thing that lived in a particular location, and a particular form, within a cell.””
