70 Charles Darwin. 



was carried away. During the passage south num- 

 bers of interesting marine animals were added to the 

 collections, among which were singular crabs with 

 suckers for clinging to other animals. The phospho- 

 rescent forms were particularly numerous, of which 

 he writes : 



" While sailing a little south of the Plata on one 

 very dark night the sea presented a most wonderful 

 and 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 

 phosphorus, 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 hori- 

 zon, from the reflected glare of these livid flames, 

 was not so utterly obscure as over the vault of the 

 heavens. 



" As we proceed further southward the sea is sel- 

 dom phosphorescent ; and off Cape Horn I do not 

 recollect more than once having seen it so, and then 

 it was far from being brilliant. This circumstance 

 probably has a close connexion with the scarcity ofj 

 organic beings in that part of the ocean. After the 

 elaborate paper by Ehrenberg on the phospho- 

 rescence 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 Ehren- 

 berg, seem, in the southern as well as in the northern 

 hemisphere, to be the common cause of this phe- 

 nomenon. The particles were so minute as easily to 



