NATURAL FOOD. 41 



which swarmed over the water can neither be conceived 

 nor expressed. When snow falls thickest and in the 

 largest flakes, the air is never so full of them as that 

 which we witnessed filled with ephemerae. I had 

 scarcely remained a few minutes in one place, when the 

 step on which I stood was covered in every part with 

 their bodies, from two to four inches deep. Near the 

 lowest step, a surface of water, of five or six dimen- 

 sions every way, was entirely covered with a thick 

 layer of them, and those which the stream swept away 

 were more than replaced by the multitudes that were 

 continually falling. I was compelled to abandon my 

 station from not being able to bear the shower of insects, 

 which, not falling perpendicularly like rain, struck me 

 incessantly, and in a manner extremely uncomfortable, 

 pelting against every part of my face, and filling my 

 eyes, nose, and mouth almost to suffocation. On this 

 occasion it was no pleasant post to hold the light, for 

 our torch-bearer had his clothes covered with the in- 

 sects in a few"* moments, which rushed in from all 

 quarters to overwhelm him." 



I am not aware that we ever have such numbers of 

 those flies in any part of Britain, but I have seen them 

 on the Rhine in immense swarms; and I once observed 

 the great square at Wiesbaden, in Nassau, strewed 

 with their dead bodies, and their white wings spread 

 out, as if a shower of snow had fallen during the night. 



Besides these there are many hundred species of 

 flies, both with four wings and two wings, that fre- 

 quent water, or the banks near water, all of which 

 become, more or less, the prey of fishes, being either 



