LUMINOUS ACALEPILE. 209 



to it, from its resemblance to a comet with its 

 streaming tail, which the old Greek astronomers 

 distinguished by that title. 



The acalephae, as already mentioned, have the 

 power of emitting light. In the seas of warmer 

 latitudes this power produces an effect so striking 

 that the most eloquent description is insufficient 

 to do justice to it. So innumerable are these 

 medusae in tropical waters, that the points of light 

 they emit illuminate the whole surface of the 

 midnight deep. Under such circumstances the 

 scene from on board ship has a magical effect. 

 As the vessel urges her way through the waters 

 where these sea lamps hang suspended, the con- 

 sequent agitation of the waters excites their illu- 

 minating powers into greater activity, and she is 

 surrounded not only with innumerable sparks of 

 phosphorescent fire, but broad flashes of light run 

 along the top of every surge that strikes her sides, 

 while globes of fire are seen just below the sur- 

 face, produced by the larger jelly-fish. If during 

 a dark night one could descend a few fathoms 

 below the surface, the appearance on looking 

 upwards would be beautiful in the extreme, pre- 

 senting, in the orbs of greater or lesser mag- 

 nitude scintillating in countless galaxies overhead, 

 much the aspect of the heavens on a starry night, 

 fretted with golden fires. 



In our own seas similar phenomena occur, though 

 much less brilliant in character. And few occu- 

 pations are more delightful to the naturalist in 

 rowing along some romantic shore, than to watch 

 p 



