ANNOTATIONS AND ADDITIONS. 57 



Lampyrides and Elaterides, in the German and Italian glow- 

 worms, and in the South American Cucuyo which lives on 

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

 charge, 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, Medusae, 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, through the stratum of water ; while electric fishes, in 

 connexion with the galvanic circuit, decompose water and 

 impart magnetism to steel bars, as I showed more than half 

 a century ago (Versuche iiber die gereizte Muskel- und 

 Nervenfaser, Bd. i. S. 438-441, and see also Obs. de Zoo- 

 logie et d' Anatomic comparee, vol. i. p. 84) ; and as John 

 Davy has since confirmed (Phil. Trans, for 1834, Part ii. p. 

 545-547), do not pass a flash through the smallest inter- 

 vening stratum. 



The considerations which have been developed make it 

 probable that it is one and the same process which operates 

 in the smallest living organic creatures, so minute that 

 they are not perceived by the naked eye, in the com- 

 bats of the serpent-like gymnoti, in flashing luminous 

 infusoria which raise the phosphorescence of the sea to 

 such a degree of brilliancy; as well as in the thunder- 

 cloud, and in the auroral terrestrial, or polar light (silent 



