INDIRECT BENEFITS DERIVED FROM INSECTS. 281 



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

 detached from the banks of the river several masses of 

 arth 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 number 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 forwardness. The 

 storm coming on, he was obliged to quit the amusing 

 scene; but when the rain ceased to fall he returned to it. 

 As soon as the cloth with which he had ordered the tub 

 to be covered was removed, the number of flies appeared 

 to be greatly augmented, and kept continually increasing: 

 many flew away, but more were drowned. Those al- 

 ready transformed, and continually transforming, would 

 have been sufficient of themselves to have made the tub 

 seem full ; but their number was soon very much en- 

 larged by others attracted by the light. To prevent their 

 being drowned, he 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 might have 

 been taken by handfulls from the candlestick. 



But the scene round the tub was nothing to be com- 

 pared with the wonderful spectacle exhibited on the 

 banks of the river. The exclamations of his gardener 

 drew the illustrious naturalist thither; and such a sight 



