Slide showing microscopic diagram of 'Salivary gland chromosones of Drosophila showing banded structure and fusion of the chromosones into the chromocentre.' Slide shows microscopic diagram of 'Salivary gland chromosones of Drosophila showing banded structure and fusion of the chromosones into the chromocentre.' Title below image reads: 'Figure 3. Salivary gland chromosones of Drosophila showing banded structure and fusion of the chromosones into the chromocentre. Magnification 600.' Late 19th century to early 20th century