14 LIVING LIGHTS. 



upon the weed, remaining, as the water left it suspended, a 

 blaze of light, until the next wave broke. My companion, 

 an old fisherman, had also been deceived by the lights ; and 

 we drifted there for some time watching these strange 

 spectres appear and disappear. 



The medusce differ in their methods of illumination. The 

 Obelia, as a free-swimming disk, is non-luminous ; but the 

 stem, or trophosome, out of which it is developed, has a fluc- 

 tuating light extending up and down its surface. In many 

 medusce the light appears to be confined to the upper portion 

 of the umbrella, to the tentacles, and to the margin of the 

 disk ; but if an oar is thrust through it, or a freshly stranded 

 jelly is torn and cut upon the sand, every portion seems to 

 become more or less luminous. 8 



The little jelly-like creatures called "comb-bearers," or 

 Ctenophores, are nearly all wonderfully phosphorescent. In- 

 stead of moving as do the ordinary jelly-fishes, they have 

 rows of comb-like paddles which move up and down in regu- 

 lar measure as they float along. In the daytime the little 

 fins gleam with gorgeous iridescent hues; while at night 

 they are brilliantly luminous, even the eggs and embryos of 

 some emitting light. 



The Beroe (Plate IV., Fig. 1) is the most familiar, but the 

 Pleurobrachia is the most graceful. Drummond refers to 

 these forms in the following lines, 



" Shaped as bard's fancy shapes the small balloon, 

 To bear some sylph or fay beyond the moon. 

 From all her bands see lurid fringes play, 

 That glance and sparkle in the solar ray 

 With iridescent hues. Now round and round 

 She whirls and twirls ; now mounts, then sinks profound." 



