MARINE PHOSPHORESCENCE. 325 



than one occasion, I have taken from the ocean a small 

 amorphous, transparent, and gelatinous medusa, which 

 when irritated, emitted a vivid rich-green light, and at 

 the same time a very strong odour, which resembled 

 that produced by the fumes of muriatic acid. 



There can be no doubt that many interesting and 

 important facts, relative to the history of luminous ma- 

 rine animals, are lost to zoology, from the circumstance 

 of illustrative specimens being captured in broad day- 

 light, (when their characteristic gleam is invisible,) and 

 when the test of a darkened apartment has not been 

 employed in their examination; and this the more 

 particularly, as there is seldom any other external sign 

 than their refulgence, to denote what living creatures 

 possess the peculiar property of emitting phosphores- 

 cent light. 



It is difficult to say in what manner this luminous 

 quality may be of use to marine animals ; or rather, 

 so many uses may be assigned, that it is hard to fix 

 upon the one which is most satisfactory. I cannot 

 believe with Mr. Kirby, that it serves as a mode of 

 defence ; because, from what we know of the nature of 

 fishes, this refulgence would be one of the surest 

 means of bringing their probable enemies upon them ; 

 and if we are to regard the economy in a destructive 

 point of view, we might rather suppose that it is in- 

 tended to direct the nocturnal predaceous fishes more 

 surely to their food ; for it is well known that they are 

 easily attracted by strong lights, and that there is no 

 better bait for capturing oceanic cuttle-fish than a cir- 

 cular piece of glittering tin, armed with hooks, and 

 lowered into the sea at midnight. But it would be 

 unjust to accuse Nature of thus wantonly investing her 

 creatures with a charm that can only tend to their 



