THE PHOSPHOKESCENCE OF THE SEA. 345 



To these Noctilucce the sea owes much of that 

 brilliant phosphorescence which at all times has been 

 the marvel of travellers. Place your vase in a dark- 

 ened room, and strike the glass, or agitate the water, 

 and you will be delighted with the spectacle presented. 

 From every part brilliant sparks appear and disappear, 

 until at length no agitation of the water will produce 

 more ; their power is exhausted, as that of the electric 

 eel is exliausted after a few shocks. You want to 

 know the cause of this phosphorescence ? Unhappily 

 the point is still sub judice. It is only since the 

 beginning of this century that the attention of natu- 

 ralists has been fixed upon the Noctilucce as sources 

 of the phosphorescence, in all times observed, and in 

 former times attributed to the presence of decaying 

 organic substance, to electricity, to "an absorption of 

 solar light disengaged in the dark," &c.* The exten- 

 sive and minute investigations of M. Quatrefages led 

 hini to the following conclusions : 



There are two difi'erent kinds of phosphorescence 

 observed in the sea. The first is of very brilliant but 

 isolated sparks, and is due principally to Starfishes, 

 Crustaceans, and Annelids. The second is of a general 

 luminous tint, over which are strewed isolated sparks, 

 and is due to the Noctilucce. These Noctilucce have 

 no special organ which produces the phosphorescence, 

 as the other animals have ; but the light emanates 

 from the whole substance of their bodies. Every 



* For the history of these opinions, and other curious details, see 

 the Memoire of M. Quatrefages, Annales cles Sciences. 1850. 



