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 sun-set 

 and dying before sun-rise, are destined never to 

 behold the dawn of day, should have so strong an 

 inclination for any luminous object. 



It is usually about the middle of August that 

 the ephemerae of the Seine and Marne are ex- 

 pected 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 recorded 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 stay- 

 ing in the boat till eight o'clock without seeing any, 

 he resolved, as a storm was foreboded, to return. 

 He had previously 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 ephemeras are here !' 

 He immediately seized one of the torches and ran to 



VOL. vi. 32 



