532 PHOSPHORESCENCE OF THE SEA. 



line of brightness. And amidst this general splendour, varied 

 forms of more glowing lustre are seen to move some like 

 ribands of flame, some like globes of living fire some gently 

 gliding through the still ocean, others more rapidly moving just 

 beneath its surface. Now, although other marine animals such 

 as the Pennatula (Fig. 717) and other Polypifera, the Pyrosoma 

 ( 1065) and other Tunicata contribute to produce this daz- 

 zling effect, it is principally due to the various species belonging 

 to the group we are now considering. 



1185. The diffused luminosity is given by minute species; 

 and on our own coasts it seems to be principally due to the 

 Noctiluca, a little animal much resembling a grain of boiled sago 

 in size and appearance, which was formerly placed amongst the 

 Acalephae, but is now generally regarded as a member of the 

 lowest section of the Animal Kingdom, the Protozoa. The 

 luminous secretion appears in all instances to become more vivid, 

 when the animal is alarmed or stimulated in any way. Hence 

 the disturbance of the water, by the gentle curling of the waves 

 over each other, or by their ripple on the shore, is marked by 

 lines of increased brilliancy. The movement of a boat, and the 

 stroke of the oars, will have the same effect. If the animals be 

 washed over the sands, they continue to display their luminosity 

 in a fainter degree for some time ; but every footstep of a per- 

 son who walks over them is studded with brilliant points. 

 And if the hands be dipped in the water thus phosphorescent, 

 and then rubbed together, they will be covered with luminous 

 spots ; which, when examined, are found to be occasioned by 

 the phosphorescent glow of these delicately formed little animals. 

 There are few parts of the British coasts where this phenome- 

 non is not occasionally witnessed. It generally follows a con- 

 tinuance* of some particular wind; but the direction required 

 varies in different parts of our island. It is thus that we obtain 

 a more accurate idea of the vast amount of animals composing 

 this tribe, than we derive from any observations that can be made 

 during the day. Their bodies are often so transparent, that they 

 can scarcely be distinguished from the water through which they 

 are diffused, except when displaying their phosphorescence. But 



