80 LIVING LIGHTS. 



CHAPTER XL 



SEAS OF FLAME. 



IN the summer months in tropical and semi-tropical waters, 

 often during several days in succession, the ocean pre- 

 sents a surface almost unruffled. The fin of some roving 

 shark, the splash of the flying-fish, or, if near shore, the 

 plunge of the pelican or gull, are the only objects that dis- 

 turb the sea of glass. At such times, after the sun had gone 

 down, we have lain in our boat, with faces as near the surface 

 as possible, and watched the wondrous panorama of the sub- 

 marine world. Here great globes of light seemed to shoot 

 through the watery space : every fish left a train of light ; 

 while the dolphin, or other great forms, gliding by, appeared 

 converted into fiery monsters ; and, as they rose to the sur- 

 face, fountains of phosphorescence burst from the sea. 



The forms which tend to produce this remarkable appear- 

 ance in the ocean depths are many ; but, in the warm waters 

 of the tropics, the most noticeable are those belonging to the 

 class known scientifically as Tunicata. Aside from their 

 luminous properties, the Tunicates are extremely interesting, 

 from the fact that they are now supposed to represent, with 

 perhaps one exception, the lowest form of backboned life, 

 being what are called degenerate forms. In the larval stage 

 of some species a noto-cord is present, which is supposed to 



