56 PHYSIOGNOMY OF PLANTS. 



( Abhandlungen der AkaJ. der Wiss. zu Berlin aus dem 

 J. 1833,8.307; 1834,8.537-575; 1838, 8.45 and 258.) 

 This acute observer has found in the organs of the Photo- 

 caris, which emits flashes of light either at pleasure or when 

 irritated or stimulated, a cellular structure with large cells 

 and gelatinous interior resembling the electric organs of the 

 Gymnotus and the Torpedo. "When the Photocaris is 

 irritated, one sees in each cirrus a kindling and nickering of 

 separate sparks, which gradually increase in intensity until 

 the whole cirrus is illuminated ; until at last the living fire 

 runs also over the back of the small Nereis-like animal, so 

 that it appears in the microscope like a thread of sulphur 

 burning with a greenish-yellow light. It is a circumstance 

 very deserving of attention, that in the Oceania (Thaumantias) 

 hemisphserica the number and situation of the sparks corre- 

 spond exactly with the thickened base of the larger cirri or 

 organs which alternate with them. The exhibition of this 

 wreath of fire is a vital act, and the whole development of 

 light is an organic vital process which in the Infusoria shows 

 itself as an instantaneous spark of light, and is repeated after 

 short intervals of repose." (Ehrenberg liber das Leuchten 

 des Meeres, 1836, 8. 110, 158, 160, and 163.) 



According to these suppositions, the luminous creatures 

 of the ocean show the existence of a magneto -electric light- 

 evolving process in other classes of animals than fishes, 

 insects, Mollusca, and Acalephse. Is the secretion of the 

 luminous fluid which is effused in some luminous creatures, 

 and which continues to shine for some time without any 

 farther influence of the living animal (for example, in 



