LIFE IN THE GREAT DEPTHS 107 



doubt prove very useful, for while the sea it- 

 self is never penetrated by the light of day yet 

 innumerable species of the creatures which 

 inhabit it carry their own light about with 

 them. 



Nearly all the lower forms of life, and many 

 of the fishes, which inhabit the deep-sea are 

 furnished with phosphorescent, light-produc- 

 ing organs. Some are provided with regular 

 search lights, others have rows of small lights 

 along their sides, others have luminous fins or 

 light-giving organs on the head, while some 

 have long, movable appendages bearing bril- 

 liant lights at their extremities. These 

 strange creatures not only illuminate their 

 own way with these natural lamps as they 

 swim about, but no doubt locate and dazzle 

 their prey as well, or attract other creatures 

 within their reach, just as a lamp or candle 

 attracts moths. 



For all we know the natural impenetrable 

 blackness of the depths of the sea may be bril- 

 liantly lit up by its countless myriads of phos- 

 phorescent inhabitants. Even the tiniest mi- 

 croscopic creatures are phosphorescent and 



