570 History of Luminescence 



animal's body." One of Macartney's medusae, M. pellucens, also 

 found by Sir Joseph Banks, is shown in figure 47. 



Among later workers interested in histology, physiology, and 

 chemistry of the light production, the names of Edward Forbes 

 (1848) , G. Busk (1852) , and P. Panceri (1872) must be mentioned 

 as pioneers. 



Ctenophores or Comb jellies 



These transparent jelly-like organisms have often been mistaken 

 for medusae and in early descriptions it is somewhat difficult to tell 

 what organism was referred to. According to Carl Chun (1880) , 

 Friedrich Martens, a ship's surgeon, saw ctenophores in the neigh- 

 borhood of Spitzbergen in 1671, and Patrick Brown near Jamaica 

 in 1756, but neither mentioned luminescence. Linnaeus included 

 two species in the tenth edition of Systema Naturae, Volvox beroe 

 and Volvox bicaudatus. Again there is no mention of luminescence. 

 The discovery of luminescence is undoubtedly connected with early 

 explorers and the general study of sea phosphorescence. 



The Abbe Dicquemare (1733-1789) in 1775 placed a drawing of 

 a ctenophore on the same plate on which he figured Noctiluca 

 miliaris for his article on sea phosphorescence. He called it a " porte- 

 iris " but made no definite statement that the animal was luminous. 

 P. Forskal described Medusa beroe in 1775 and it is quite certain 

 that luminous ctenophores were observed in 1800 by Louis Bosc 

 (1759-1828), and in 1801 by S. L. Mitchill (1764-1831), professor 

 of chemistry, natural history, and philosophy at Columbia Univer- 

 sity, and a member of the American Philosophical Society. Many 

 other students of marine forms since that time have described lumi- 

 nous comb jellies. 



The most important contribution of ctenophores to biolumines- 

 cence knowledge comes from the discovery in 1862 of G. J. Allman 

 (1812-1898) that daylight inhibits the luminescence, but if the ani- 

 mals are placed in the dark for twenty minutes or so, they can again 

 emit light on stimulation. Allman (1862) also noted that the de- 

 veloping eggs and embryoes of ctenophores are luminescent. The 

 histology was first studied by P. Panceri (1872) and A. Agassiz 

 (1874) . Finally it should be mentioned that the ctenophores belong 

 among the relatively few luminous forms which do not need dis- 

 solved oxygen for light production, a discovery of the author in 

 1926. 



