MOTIONS OF INSECTS. 



297 



hold the light of that orb — should have so strong an inclin- 

 ation for any luminous object. To hold a flambeau when 

 they appeared was no very pleasant office ; for he who filled 

 it, in a few seconds had his dress covered with the insects, 

 which rushed from all quarters to him. The light of the 

 flambeau exhibited a spectacle which enchanted every one 

 that beheld it. All that were present, even the most ignorant 

 and stupid of his domestics, were never satisfied with looking 

 at it. Never had any armillary sphere so many zones, as 

 there were here circles, which had the light for their centre. 

 There was an infinity of them — crossing each other in all di- 

 rections, and of every imaginable inclination — all of which 

 were more or less eccentric. Each zone was composed of an 

 unbroken string of Ephemerae, resembling a piece of silver 

 lace formed into a circle deeply notched, and consisting of 

 equal triangles placed end to end (so that one of the angles of 

 that which followed touched the middle of the base of that 

 which preceded), and moving with astonishing rapidity. The 

 wings of the flies, which was all of them that could then be 

 distinguished, formed this appearance. Each of these crea- 

 tures, after having described one or two orbits, fell upon the 

 earth or into the water, but not in consequence of being 

 burned. 1 Reaumur was one of the most accurate of observers ; 

 and yet I suspect that the appearance he describes was a 

 visual deception, and for the following reason. I was once 

 walking in the day-time with a friend 2 , when our attention 

 was caught by myriads of small flies, which were dancing 

 under every tree ; — viewed in a certain light they appeared 

 a concatenated series of insects (as Reaumur has here described 

 his Ephemerae) moving in a spiral direction upwards; — but 

 each series, upon close examination, we found was produced 

 by the astonishingly rapid movement of a single fly. Indeed, 

 when we consider the space that a fly will pass through in a 

 second, it is not wonderful that the eye should be unable to 

 trace its gradual progress, or that it should appear present in 

 the whole space at the same instant. The fly we saw was a 

 small male Ichneumon. 



1 Reaum. vi. 484. t. xlv. f. 7. 



2 The persons observing the appearance here related were the authors of this 

 work. 



