NATURE'S FIREWORKS 49 



of the surface which during the day is seen as foam 

 now glowed with a pale light. The vessel drove 

 before her bows two billows of liquid phosphorus, 

 and in her wake she was followed by a milky train. 

 I am inclined to consider that the phosphorescence 

 is the result of the decomposition of the organic par- 

 ticles, by which process (one is tempted almost to call 

 it a kind of respiration) the ocean becomes purified.' 



In many creatures this power to emit light is a 

 means of defence, while in some it acts as a lamp of 

 attraction. The poison threads of the jelly-fish would 

 prove to be very disagreeable food for fishes, hence 

 Mr. Chisholm conjectures, and with very good reason, 

 that in being luminous they act as a danger signal 

 to others, while the luminosity affords security to 

 themselves. Several of our great biologists are 

 agreed that while this luminosity of marine creatures 

 serves a grand purpose in beautifying the ocean 

 surface at night, it renders a more serviceable duty 

 in that it illumines the deep abysmal waters away 

 down where the rays of the sun can never penetrate ; 

 but for this the vast ocean depths would remain 

 in utter darkness. 



Whether photographs can be taken with this 

 light remains to be proved, but with the strides 

 photography is making, we may expect to see 

 the floors of oceans and the denizens of the deep 

 photographed in all their natural conditions. These 

 are not times in which to say such achievements 

 are an impossibility. 



D 



