LUMINESCENCE 



547 



Intracellular Luminescence 



Intracellular luminescence is also widespread and is usually associated 

 with the development of special photophores. These may attain great com- 

 plexity and possess reflectors, lenses and screens, as well as photogenic 



Fig. 13.8. Luminescent Teleost Fishes 

 (a) Silvery hatchet-fish, Argyropelecus olfersii ( x 1-4) (after Clemens and Wilby, 1 946) ; 

 (b) midshipman Porichthys notatus (x §) (after Greene, 1899); (c) Angler-fish Ceratias 

 couesi ( x %). 



cells. The simplest form of intracellular luminescence is found in Protozoa. 

 In Noctiluca the light appears from small granules scattered about the 

 periphery of the cell and along protoplasmic strands in the cell interior. 

 Quatrefages observed that lighting often begins in two spots near the oral 



