PYROSOMA. 459 



They are, however, not all of them of such sedentary 

 habits ; in one remarkable genus, sometimes, though 

 rarely, met with upon our coasts, the Pyrosoma 

 (PL VIII. fig. 3), or, as the word is literally traiis- 

 lateable, the "body of flame," each seeming indi- 

 vidual is, in fact, a little colony of Ascidians, every 

 one lodged in its own cell, distinct, and yet in- 

 separably connected with its fellows. Collected into 

 the figure of a gelatinous cylinder, open at one 

 extremity and closed at the other, these strangely 

 compound beings float in the seas like meteors of 

 this lower world, shedding around them a halo of 

 light, brilliant indeed, but surpassed in beauty by the 

 gorgeous colours which it serves to disclose ; colours 

 that come and go at pleasure, glorying, as it were, 

 in their subtle changes, passing rapidly from a lively 

 red to aurora, to orange, to green, and to azure-blue ; 

 a magic scene, compelling more than the admira- 

 tion of every beholder : 



M the fair star, 



That gems the glittering coronet of morn, 

 Sheds not a light so mild, so powerful." 



"Only imagine," says Humboldt, "the superb 

 spectacle which we enjoyed some days ago, when, in 

 the evening, from seven to eleven o' clock, a con- 

 tinuous band of those living globes of fire passed near 

 our vessel, some of them giving out, while swimming 

 beneath the surface of the sea, a circle of light of a 

 foot and a half in diameter, by which we could 

 distinguish, at a depth of fifteen feet, tunnies and 

 other fishes, which have followed us for several 



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