310 NATURAL HISTORY OF AQUATIC INSECTS CH. 



19th I received warning from my angler, and the 

 same day, three hours before sunset, I took his boat 

 to examine the banks of the Marne and Seine. Where 

 the shore was level and sheltered from the wind, 

 heaps of dead Ephemerae could be seen. During this 

 excursion by water I removed some clods of earth 

 which were riddled with holes, and placed them in a 

 large bucket of water as near as possible in their 

 original position. The sides of the clods exhibited 

 larvae partly or completely exposed. At length the 

 sun set. At that time Ephemerae were to be seen 

 flying here and there over the Seine, but at half past 

 seven the number showed no important increase. I 

 crossed over into the Marne, where there seemed to 

 be still fewer. At about eight o'clock the coming on 

 of evening and the flashes of an approaching thunder- 

 storm caused me to return into an arm of the Marne, 

 which washes the stairs leading from my own garden. 

 I had the bucket containing the Ephemera-larvae 

 carried into the garden, but as soon as the men had 

 reached the top step they cried out that a prodigious 

 number of Ephemerae were emerging. I seized one 

 of the lanterns with which they had come to meet 

 me, and ran to see what was going on. All those 

 clods which stood out of the water were covered with 

 the flies, some beginning to cast their skin, others 

 nearly free, others ready to take flight, while in the 

 water beneath were larvae whose transformation was 

 less advanced. While I was examining the contents 

 of the bucket the storm broke, and forced me to take 

 refuge in the house. Before leaving the bucket I 

 threw over it a cloth, to prevent the Ephemerae from 



