MOTIONS OF INSECTS. 373 



A more extraordinary display of insect dancing, 

 and which in some instances seems better entitled to 

 the name of a ball, than our own dancing parties, 

 occurs amongst the day-flies {Ephemeridce) , whose 

 short-lived existence renders it necessary for them to 

 make the most of the few hours at their disposal. 

 The narrative of the observations made by Reaumur 

 upon this subject is too interesting to admit of much 

 abridgment. It is not a little singular, he remarks, 

 that moths, which fly only in the night, and shun the 

 day, should be precisely those that come to seek the 

 light in our apartments ; but it is still more wonderful 

 that the ephemerae- — which, appearing after sunset 

 and dying before sunrise, are destined never to be- 

 hold the dawn of day, — should have so strong an in- 

 clination for any luminous object. 



It is usually about the middle of August that 

 the ephemerae of the Seine and Marne are expected 

 by the fishermen, and when their season is come 

 they talk of the manna beginning to appear, calling 

 the insects by this term on account of the quantity 

 of food for the fish, which falls as the manna is re- 

 corded to have done in the desert. On the 19th 

 of August, Reaumur, having received notice that the 

 flies had begun to appear, and that millions of them 

 were coming out of the water, got into his boat about 

 three hours before sunset; but after staying in the 

 boat till eight o'clock without seeing any, he resolved, 

 as a storm was foreboding, to return. He had pre- 

 viously detached from the banks of the river several 

 masses of earth filled with pupae, which he put into 

 a large tub full of water. His servants, who were 

 carrying the tub home, had scarcely set it upon one 

 of the steps of the stairs leading from his garden 

 to the Marne, when he heard them exclaim, " What 

 a prodigious number of ephemerae are here I " He 

 immediately seized one of the torches and ran to the 



