ANNOTATIONS AND ADDITIONS. 263 



Akad. der Wiss. zu Berlin aus dem J. 1833, s. 307; 1834, s. 537- 

 575 ; 1838, s. 45 and 258.) This acute observer has found in the 

 organs of the Photocaris, which emits flashes of light either at plea- 

 sure 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 flickering of separate sparks, 

 which gradually increase in intensity until the whole cirrus is illumi- 

 nated; 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 (Thau- 

 mantias) hemisphserica the number and situation of the sparks cor- 

 respond 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." (Ehren- 

 berg liber das Leuchten des Meeres, 1836, s. 110, 158, 160, and 

 163.) 



According to these suppositions, the luminous creatures of the 

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

 cess 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 ex- 

 ample, in Lampyrides and Elaterides, in the German and Italian 

 glowworms, and in the South American Cucuyo, which lives on 

 the sugar-cane), only a consequence of the first electric discharge, 

 or is it simply dependent on chemical mixture? The shining of 

 insects surrounded by air has doubtless other physiological causes 

 than those which occasion the luminosity of inhabitants of the water, 

 fishes, MedusaB, and Infusoria. The small Infusoria of the ocean, 

 being surrounded by strata of salt water, which is a good conducting 

 fluid, must be capable of an enormous electric tension of their light- 

 flashing organs, to enable them to shine so intensely in the water. 

 They strike like Torpedos, Gymnoti, and the Tremola of the Nile, 



