218 LUMINOSITY OF THE SEA. 



But this luminosity is not entirely confined to 

 the minute creatures of the sea. Some fish have 

 the power of emitting light. Some species of the 

 shark emit a greenish light ; and the sun-fish is 

 said, when seen down in the sea on a dark night, 

 to glow like a white-hot cannon-ball. Fish when 

 dead and putrid frequently glow in the dark with 

 a truly magnificent light, as can be proved by every 

 one who will take the trouble to procure several 

 kinds of fish, and keep them, for the purpose of 

 proving the fact, in a dark closet. 



Of all the minute inhabitants of the deep, that 

 which is to our mind the most curious, both as 

 to its nature and its stupendous works, is the 

 coral insect. This creature is much too important 

 to be dragged in at the tail of a chapter. We will, 

 therefore, commence its history in a new one. 



