422 LUMINOSITY OF THE OCEAN. 



vessel containing sea water, ceased altogether to 

 emit light, or emitted it but sparingly while they 

 remained at rest. On the water, however, being 

 agitated, or when one of the masses of animals 

 was taken into the hand, the whole became 

 instantly illuminated by myriads of bright dots, 

 much resembling in hue the points on the elytra 

 of a diamond beetle {Curculio imperialls, Fab.) 



The Pyrosoma, thus enveloped throughout its 

 whole extent in a flame of bright phosphorescent 

 light gleaming with its peculiar hue, presented 

 a most splendid spectacle ; the light shed by it 

 was sufficient to render objects distinctly visible 

 in every part of an otherwise dark room. If long 

 retained in the hand, or returned to a quiescent 

 state in the water, the luminous spots gradually 

 faded, and no light was visible until the animal 

 was again disturbed, when the illumination in- 

 stantly returned with all its vivid splendour. 

 After death it emitted no light. 



The mass of Pyrosoma, of the usual cylin- 

 drical form and gelatinous substance, was about 

 four inches in length and one and a half in 

 circumference. The tube, passing along its 

 middle, is described as being open at both ends; 

 the orifice at the broader extremity being much 

 better defined in its circular form, larger, and 

 more distinct than that of the opposite end. 



