1833.] PHOSPHOKESOEXCE OF THE SEA. 155 



circumstance probably has a close connection with the scarcity of 

 organic beings in that part of the ocean. After the elaborate 

 paper,* by Ehrenberg, on the phosphorescence of the sea, it is 

 almost superfluous on my part to make any observations on the 

 subject. I may however add, that the same torn and irregular 

 particles of gelatinous matter, described -by Ehrenberg, seem in 

 the southern as well as in the northern hemisphere, to be the 

 common cause of this phenomenon. The particles were so minute 

 as easily to pass through fine gauze; yet many were distinctly 

 visible by the naked eye. The water when placed in a tumbler 

 and agitated, gave out sparks, but a small portion in a watch-glass 

 scarcely ever was luminous. Ehrenberg states that these particles 

 all retain a certain degree of irritability. My observations, some 

 of which were made directly after taking up the water, gave a 

 different result. I may also mention, that having used the net 

 during one night, I allowed it to become partially dry, and having 

 occasion twelve hours afterwards to employ it again, I found the 

 whole surface sparkled as brightly as when first taken out of the 

 water. It does not appear probable in this case, that the particles 

 could have remained so long alive. On one occasion having kept 

 a jelly-fish of the genus Diansea till it was dead, the water in which 

 it was placed became luminous. When the waves scintillate with 

 bright green sparks, I believe it is generally owing to minute 

 Crustacea. But there can be no doubt that very many other 

 pelagic animals, when alive, are phosphorescent. 



On two occasions I have observed the sea luminous at consider- 

 able depths beneath the surface. Near the mouth of the Plata 

 some circular and oval patches, from two to four yards in 

 diameter, and with defined outlines, shone with a steady but pale 

 light ; while the surrounding water only gave out a few sparks. 

 The appearance resembled the reflection of the moon, or some 

 luminous body ; for the edges were sinuous from the undulations 

 of the surface. The ship, which drew thirteen feet water, passed 

 over, without disturbing these patches. Therefore we must 

 suppose that some animals were congregated together at a greater 

 depth than the bottom of the vessel. 



Near Fernando Noronha the sea gave out light in flashes. The 

 appearance was very similar to that which might be expected from 



* An abstract is given in No. IV. of the Magazine of Zoology and 

 Botanv. 



