NATURAL HISTORY. 
231 
The plying of thefe little oars is exceedingly 
carious. The larva: make their refidence by 
perforating, or making holes in the banks of 
rivers ; and, when the. water falls, or de- 
creafes, they make other holes lower, in or- 
der to have ready accefe to their favourite ele- 
ment. Flames attraft them, fo as to caufo 
them to form a thoufand circles round fuch 
a ligKt, with an amazing regularity. One 
fingle female will lay feven or eight eggs, 
which fink to the bottom of the water, 
where they are depofited. The larvae which 
they produce, cohdrucl habitations to (lielter 
them from every danger. The flies, haring 
propagated, immediately die in heaps. — 
Fifhermen confider thefe multitudes of de- 
ftroyed infefts, as manna for the fifli. We 
can, therefore, perceive, that even this in- 
feft, which cannot, for its very fliort exifl- 
ence, be of much fervice during life, is, by 
the wifdom of the creator, fo calculated, as 
to be of efleiitial fervice, even in its depart- 
ed hate. 
G ENUS 
