Bacteria |G to F extending| |Barnard, | Photographic. | toward D for | | 1902 | | long exposure | | | Bacteria |Somewhat beyond | |Fisher, |Eye observation. | G to D | | 1888 | Bacteria | .58 - .43 | |Förster, |Eye observation | | | 1887 | Zeiss. Abbe | | | | microspectral | | | | ocular. Bacteria | >.500 to .350 | Bright |Forsyth, |Photographic, | | band | 1910 | quartz | | at .4 | | spectroscope. Agarious | 0.56-0.48 | |Ludwig, |Eye observation, melleus | (approximately)| | 1884 | Sorby Brown | | | | microspectroscope. Xylaria | .54 - .46 | |Ludwig, |Eye observation, hypoxylon | (approximately)| | 1884 | Sorby Brown | | | | microspectroscope. Micrococcus |b into the | |Ludwig, |Eye observation, Pflugeri | violet | | 1884 | Sorby Brown | | | | microspectroscope. Mycelium X | .570 - .480 | |Molish, |Eye observation, | | | 1904, | Zeiss comparison | | | book | spectroscope. Bacterium | .570 - .450 | |Molish, |Eye observation, phosphoreum | | | 1904, | Zeiss comparison | | | book | spectroscope. Bacterium | .570 - .450 | |Molish, |Eye observation, phosphorescens| | | 1904, | Zeiss comparison | | | book | spectroscope. Bacillus | .570 - .450 | |Molish, |Eye observation, photogenes | | | 1904, | Zeiss comparison | | | book | spectroscope. Pseudomonas | .570 - .450 | |Molish, |Eye observation, lucifera | | | 1904, | Zeiss comparison | | | book | spectroscope. ----------------+----------------+---------+-----------+-------------------- As first shown by Dubois (1886) for _Pyrophorus_, and confirmed by myself for _Cypridina_, the light is not polarized in any way. I may add that the _Cypridina_ light like any other light may be polarized by passing through a Nicol prism.