THE METEORS OF THE SEA. 17 



observed on one of his collecting-tours. He says, " While 

 sailing a little south of the Plata on one very dark night, 

 the sea presented a wonderful and most beautiful spectacle. 

 There was a fresh breeze, and every part of the surface which 

 during the day is seen as foam now glowed with a pale light. 

 The vessel drove before her bows two billows of liquid phos- 

 phorus, and in her wake she was followed by a milky train. 

 As far as the eye reached, the crest of every wave was bright ; 

 and the sky above the horizon, from the reflected glare of 

 these livid flames, was not so utterly obscure as over the 

 vault of the heavens. . . . Having used the net during one 

 night, I allowed it to become partially dry; and having occa- 

 sion, twelve hours afterward, to employ it again, I found the 

 whole surface sparkling 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 sea-jelly of the genus Diancea till it 

 was dead, the water in which it was placed became luminous. 

 . . . Near Fernando Do Norhona, the sea gave out light in 

 flashes. The appearance was very similar to that which 

 might be expected from a large fish moving rapidly through 

 a luminous fluid. To this cause the sailors attributed it ; at 

 the time, however, I entertained some doubts, on account 

 of the frequency and rapidity of the flashes." 



To Spallanzani is due the credit of first calling attention to 

 the phosphorescence of the jelly-fishes or sea-jellies ; he having 

 observed it in the Mediterranean jelly, Pelagia phosphorea, 

 which is luminous over its entire surface. He subsequently 

 made some interesting experiments with Aurelia pliosphorea, 

 a jelly-fish similar to one on our coast, and came to the conclu- 

 sion that the Uyht-emitting organs lay in the arms, tentacles, 



