2^2 I N S E C T S. 



their external (heath. Along the banks of the Rhine, or the Seine 

 near Paris, about three days in the midft of fummer, their numbers and 

 affiduity are aftonifliing : the whole air fcems alive with the new-born 

 race, and the earth is covered with their remains. The aurelias beneath 

 the water wait only for evening to begin their transformation. The mod 

 early ihake off their old garments about eight o'clock j the later before 

 nine. They are fcarce lifted above the water, ere their old fbeathing 

 fkin burfts ; and through it a fly ifliies, whofe wings, the fame inftant, 

 are* unfolded, and lift it into the air. Millions thus rife to the furface ; 

 and fill every quarter with their flutcerings. But the whole foon fall to 

 the ground, and cover the earth, like a deep fnow ; every objed they 

 touch becomes fatal ; and they inftantly die, if they hit even againft each 

 other. 



The males feem only born to die: they follow not the oppofite fex j but 

 after fluttering an hour or two, they drop. But the females are fcarce rifen 

 from the water, and have dried their wings, ere they haflen to drop their eggs 

 back again. If they happen to flutter on land, they depofite their burthen 

 where they drop. We know not how thefe eggs are fecundated. The females 

 are in fuch hafte to depofite their eggs, that multitudes fall to the ground i 

 but the greatell part are laid in the water. As they flutter on the furface, 

 two clufl:ers are ken ifl!uing from the extremity of their body, each con- 

 taining about three hundred and fifty eggs. 



It would feem there was a neceflity for fuch fertility, as in its reptile fl:ate 

 it is the favorite food of every kind of frelh-water fifli. In vain thefe litde 



- animals form galleries at the bottom of the river ; many kinds of fifh break 

 in on their retreats, and thin their numbers. Thefe infeds are the mod 

 grateful bnit for fifli. The ufual date of thefe flies is two or three hours ; 

 yet fome live fcveral days; and one kind, after quitting the water, has to 

 quit another cafe or ikin, Thefe are often ktn in fields and woods, but 

 frequently in the vicinity of water. They are often found (licking on walls 



, ana trees, with the head downwards, without changing place, or fenfiblc 

 motion ; waiting for the moment when they Ihall be diverted of their laft 

 garment, which fometimes does not happen for two or three days. 



CATER 



