EPHEMERA. 
* 374 
surface, the insect digs fresh holes, when from any 
cause the waters are found to decrease. 
Ephemerae always effect their transformation in 
the evening, and the report of the multitudes which 
covered the Seine every night, excited the curiosity 
of that famous entomologist M. Reaumur, who in 
August 1738 waited for some time after sun-set on 
the banks of that river in order to observe the phae- 
nomenon. Disappointed, however, of his purpose, 
he returned home with a tub partly filled with 
their holes and larvae ; but had scarcely set it down, 
when every part of the earth that was above the 
water in the tub, was covered with ephemerae, in 
the act of emerging from their former skins. The 
quantities which flew from the tub, whose number 
seemed to increase every minute, induced this gen- 
tleman to pay another visit to the river, where he 
was greatly surprised at the quantity of ephemerae 
which filled the air, and which, according to his 
account, surrounded him like a thick fall of snow. 
This amazing fall prevailed to such a degree, that 
he had scarcely remained a few minutes in one place, 
before the step where he stood was completely 
covered with their bodies to the depth of two or 
three inches. A thick coat of these insects covered 
the water for at least six feet from the bank, and 
those which the current carried down the river 
were immediately replaced by others. M. Reaumur 
was occasionally obliged to abandon his station and 
retreat to a higher place, in order to avoid the 
