10 



GLIMPSES OF NATURE. 



Fig. 4. Noctiluca. 



there it seems to exhibit spaces and gaps in its sub- 

 stance, and you may discover traces or beginnings of 

 definite tissues in the soft mass whereof it consists. 



This, then, is the 

 Noctiluca, which 

 emphatically con- 

 stitutes the 

 " night-light" of 

 the sea. 



Swarming in 

 myriads in the 

 waters of the 

 ocean, these ani- 

 malcules, under 

 favourable con- 

 ditions of heat 

 and other phases 

 relating to their vital activity, give forth the strange 

 weird gleam you see shooting along the crest of the 

 waves. You can recall Coleridge's lines with apt 

 force, when on this quiet night you sit and watch the 

 play of phosphorescence on the sea : 



Beyond the shadow of the ship, I watched the water-snakes ; 



They moved in tracks of shining white, 



And when they neared the elfish light 

 Fell off in hoary flakes. 



Beyond the shadow of the ship, I watched their rich attire ; 



Blue, glossy green, and velvet black, 



They coiled and swam, and every track 

 Was a flash of golden fire. 



How and why these and other animals exhibit a 

 phosphorescent light is a problem towards the solution 

 of which science has, at least, advanced within reason- 

 able distance. The Noctiluca is undoubtedly the cause 



