Slide showing a table illustrating 'viability of some mutations and their combinations in Drosphila funebris, expressed in percentage of the viability of wild type'. Slide shows a table illustrating 'viability of some mutations and their combinations in Drosphila funebris, expressed in percentage of the viability of wild type'. Title of slide reads: 'Table 1 - viability of some mutations and their combinations in Drosphila funebris, expressed in percentage of the viability of wild type (after Timofeeff-Ressovsky).' Row headings: 'mutation', 'temperature', 'combination' and 'temperature' again. Listed under 'mutation' are: 'eversae', 'singed', 'abnormes', 'miniature', 'bobbed' and 'lozenge'. Late 19th to early 20th century