INDIRECT BENEFITS DERIVED FROM INSECTS. 283 



when they did not begin to show themselves in numbers 

 till the 18th of August. On the 19th, having received 

 notice from liis fisherman that the flies had appeared, 

 he got into his boat about three hours before sun-set, 

 and detached from the banks of the river several masses 

 of earth filled with pupae, which he put into a large tub 

 full of water. This tub, after staying in the boat till 

 about eight o'clock without seeing any remarkable num- 

 ber of the flies, and being threatened with a storm, he 

 caused to be landed and placed in his garden, at the foot 

 of which ran the Marne. Before the people had landed 

 it, an astonishing number of Ephemerae emerged from 

 it. Every piece of earth that was above the surface of 

 the water was covered by them, some beginning to quit 

 their slough, others prepared to fly, and others already 

 on the wing; and every where under the water they 

 were to be seen in a greater or less degree of forward- 

 ness. The storm cording on, he was obliged to quit the 

 amusing scene ; but when the rain ceased to fall he re- 

 turned to it. As soon as the cloth with which he had 

 ordered the tub to be covered was removed, the num- 

 ber of flies appeared to be greatly augmented, and kept 

 continually increasing : many flew aw ay, but more wer§ 

 drowned. Those already transformed, and continually 

 transforming, would have been sufficient of themselves 

 to have made the tub seem full ; but their number was 

 soon very much enlarged by others attracted by the 

 light. To prevent their being drowned, lie caused the 

 tub to be again covered with the cloth, and over it he 

 held the light, which was soon concealed by a layer of 

 these flies, that miglit have been taken by handfulls from 

 the candlestick, 



