2S2 INDIRECT BENEFITS DERIVED FROM INSECTS. 



he had never witnessed, and could scarcely find words 

 to describe. " The myriads of Ephemerae," says he, 

 " which filled die air over the current of the river, and 

 over the bank on which I stood, are neither to be ex- 

 pressed nor conceived. When the snow falls with the 

 largest flakes, and with the least interval between them, 

 the air is not so full of them as that which surrounded 

 us was of Ephemerae. Scarcely had I remained in one 

 place a few minutes, when the step on which I stood was 

 quite concealed with a layer of them from two to four 

 inches in depth. Near the lowest step a surface of wa- 

 ter of five or six feet dimensions every way was entirely 

 and thickly covered by them : and what the current car- 

 ried off was continually replaced. Many times I was 

 obliged to abandon my station, not being able to bear 

 the shower of Ephemerae, which, falling with an obliquity 

 less constant than that of an ordinary shower, struck 

 continually, and in a manner extremely uncomfortable, 

 every part of my face t — eyes, mouth and nostrils were 

 filled with them." To hold the flambeau on this occa- 

 sion was no pleasant office. The person who filled it 

 had his clothes covered in a few moments with these flies, 

 which came from all parts to overwhelm him. — Before 

 ten o'clock this interesting spectacle had vanished. It 

 was renewed for some nights afterwards, but the flies 

 were never in such prodigious numbers. The fisher- 

 men allow only three successive days for the great fall 

 of the manna: but a few flies appear both before and af- 

 ter, their number increasing in one case, in the other di- 

 minishing. Whatever be the temperature of the atmo- 

 sphere, whether it be cold or hot, these flies invariably 

 appear at the same hour in the evening, that is, between 



