584 History of Luminescence 



made by G. W. Muller (1891) and H. Watanabe (1897), but the 

 extensive biochemical investigation of these forms did not begin 

 until 1916, when the author pointed out the value of these organisms 

 for such research (see E. N. Harvey, 1952) . 



COPEPODS 



The discovery of luminescence in copepods begins with a miscon- 

 ception. One of the most striking of the group, Sapphirina, is a 

 transparent floating form whose chitinous surface structure is such 

 as to give colored interference patterns in daylight, an irridescence 

 which was mistaken for luminosity by the earlier observers. Such 

 is the interpretation by Meyen (1834) of a luminous animal called 

 Oniscus fulgens by Johann Anderson (1674-1743) in 1746, although 

 others believe that Anderson saw luminous shrimp. J. V. Thomp- 

 son, in 1829, also called Sapphirina luminous but the opal-like play 

 of colors disappears completely in total darkness. 



W. Giesbrecht, to whom so much of copepod knowledge is due, 

 believed that O. Fabricius in 1780 probably saw the modern genus, 

 Metridia, common in Davis Straight, although the record is ques- 

 tionable. Fabricius described a Cyclops brevicornis, also figured by 

 O. F. Midler. One of D. Viviani's (1805) figures looks like a 

 copepod, and there can be no doubt but that W. Baird (1830, 1831, 

 1843) in his articles on the " Luminousness of the Sea " saw lumi- 

 nous copepods called Cyclops. Many others have observed the light, 

 although the animals are so small that they would be easily over- 

 looked without a microscope. Important information on histology, 

 and some chemical studies are to be found in Giesbrecht's (1895) 

 great monograph on the pelagic copepods in the vicinity of Naples. 



AMPHIPODS 



In recent years some species of deep-sea amphipods have been 

 reported as possessing luminous organs but the light has not been 

 observed, and the luminosity awaits confirmation. Amphipods are 

 chiefly famous for infection by parasitic luminous bacteria which 

 multiply in the living animal, making it luminous for a short time, 

 but eventually killing the host. The first record of such an infection 

 was by Thulis and Bernard (1786) for the " Crevette," identified by 

 Etienne Louis Geoffroy (1800: 2: 667) as Cancer macrurus rufescens 

 and by Ehrenberg (1834) as Cancer pulex. The common fresh- 

 water amphipod of Europe is Gammarus pulex. 



The report of Thulis and Bernard was published in the Journal 

 de Physique, again indicating the interest of contemporary physicists. 



