54 THE PYROSOMA. 



There is another source ■ of this phosphorescent light 

 remaining to be noticed ; this appears to be certain 

 animal matters in a state of decomposition. Fishes, 

 lobsters, etc. when putrescence has commenced, are, as 

 is well known, luminous in the dark. 



Now, in the water of the ocean, there is no lack of 

 animal matter, every drop has its inhabitants : of the 

 myriads of fishes, articulata, mollusca, etc. imagination 

 cannot conceive an adequate idea ; and death reigns in the 

 waters, as well as on the land. But is it to the decom- 

 position of its animal substances that the sea in all cases 

 owes its luminous appearance ? Certainly not ; but this 

 is probably the most extensive and prevailing cause. 

 However, it is doubtless also to be often attributed to 

 the presence of dense shoals of luminous marine animals 

 spreading over a greater or less extent of surface. Of these 

 animals the pyrosoma seems to be that most usually pro- 

 ductive of the phenomenon in question. Collected in 

 shoals, often covering miles of the ocean, and conse- 

 quently in number beyond human calculation, these 

 animals illuminate the gloomy deep with beaming radi- 

 ance. Some idea of their numbers, however, may be 

 formed from the following account, in Mr. G. Bennett's 

 narrative of his " Wanderings." 



" On June 8, being then in 00'^ 30' south, and Ion- 



