LUMINOSITY OF FISH. 395 



'the one-thousandth of an inch in diameter. 

 Millions may be easily contained in a bucketful 

 of sea-water. On examination under the mi- 

 croscope, it appears that they possess the power 

 of squeezing out a phosphorescent fluid, which 

 leaves a line of light in the water. 



ITOCTILTTCA MILIAEIS. (MAGNIFIED.) 



In the British seas these little animalcules are 

 often found congregated together in innumerable 

 millions. Dr. Prinsr, in a paper communicated 

 to the British Association in 1849, details some 

 interesting results of experiments upon these 

 phosphorescent creatures. " Galvanism increased 

 the luminosity ; oxygen gas, and carbonic acid 

 gas, also increased the light; but the latter most 

 speedily killed the animal; sulphuretted hy- 

 drogen quickly destroyed the light; nitrogen, 

 nitrous oxide, and hydrogen, produced little 6t 



