"The chromosome is at least as powerful an icon of heredity as DNA but so far has not held a central place in the historiography of twentieth-century life sciences. [Heredity under the Microscope] sets this record straight by directing its lense on the cytogenetic study of human chromosomes and the many contexts in which chromosome images came to matter. It opens fascinating new perspectives on the 'century of the gene' that go far beyond the earlier focus on the history of classical and molecular genetics."