136 PHOSPHORIC INSECTS. 



examine them in the daytime, these insects, as 

 every one knows, are not characterized by any 

 extraordinary feature, nor do they astonish us by 

 their beauty. 



Lampyris noctiluca (fig. 25) is the species most 

 abundant in England, Belgium, Germany, and the 



north of France. We all know it well. We have 

 all admired it silently shining on the fresh green 

 sward of the country, and we all value this insect 

 for the agreeable souvenirs which it calls forth as 

 we contemplate its soft light. These little shining 

 beings remind us of our younger days. They 

 were shown to us in our early childhood, and we 

 have been taught to look upon them as something 

 mysterious. ' f Those sparks in the grass, what are 

 they ? Insects ! But the light ! " How often 

 have we not heard such questions. Or this, again : 

 " Tell me, then, you, a philosopher, what is it, 

 definitely, that produces the light of the glow- 

 worm ? " To which we can only reply, " Those 

 sparks, in the grass have excited the inquisitive- 



