TftE NIGHT-SPINMING NEREIS. 54I 



sons, but particularly in summer before stormy wea- 

 ther, when they are more agitated and more lumi- 

 nous than at other times. Their numbers, and 

 wonderful agility, added to their pellucid and shin- 

 ing quality, do not a little contribute to their illumi- 

 nating the sea ; for myriads of these animalcules 

 may be contained in a small cup of sea- water. In- 

 numerable quantities of them lodge in the cavities 

 of the scales of fishes, and to them probably the fish: 

 may in some measure become luminous. " I have 

 observed with great attention (says Barbut) a fish 

 just caught out of the sea, whose body was almost 

 covered with them, and have examined them in the 

 dark : they twist and curl themselves with amazing 

 agility, but soon retire out of our contracted sight ; 

 probably on account of their glittering numbers 

 dazzling the eye, and their extreme minuteness 

 eluding our researches. It is to be observed that, 

 when the unctuous moisture which covets the 

 scales of fishes is exhausted by the air, these animals 

 are not to be seen ; nor are the fishes then nocti- 

 lucous, that matter being perhaps theiF nourishment 

 w T hen living, as they themselves afford food to many 

 marine animals. They do not shine in the day- 

 time, because the solar rays are too powerful for 

 their light, however aggregate, or however immense 

 their number*." 



Their appearance is particularly brilliant when 

 the wind is in the east and south-east points, and in 

 winter nights preceded by a warm day. If water 



Barbut's Genera Vurmium, 



