Nature's Night Lights. 1 73 



place are simultaneously affected in the same way, 

 and at sucli times they mass themselves together in 

 myriads, as if for migration, or for some other great 

 purpose. Mr. Bigg-Wither, in South Brazil, and 

 D'Albertis, in New Guinea, noticed these firefly 

 gatherings ; I also once had the rare good fortune 

 to witness a phenomenon of the kind on a very grand 

 scale. Riding on the pampas one dark evening an 

 hour after sunset, and passing from high ground 

 overgrown with giant thistles to a low plain covered 

 with long grass, bordering a stream of water, I 

 found it; all ablaze with myriads of fireflies. I 

 noticed that all the insects gave out an exceptionally 

 large, brilliant light, which shone almost steadily. 

 The long grass was thickly studded with them, 

 while they literally swarmed in the air, all moving 

 up the valley with a singularly slow and languid 

 flight. When I galloped down into this river of 

 phosphorescent fire, my horse plunged and snorted 

 with alarm. I succeeded at length in quieting him, 

 and then rode slowly through, compelled to keep 

 my mouth and eyes closed, so thickly did the insects 

 rain on to my face. The air was laden with the 

 sickening phosphorous smell they emit, but when I 

 had once got free of the broad fiery zone, stretching 

 away on either hand for miles along the moist valley, 

 I stood still and gazed back for some time on a scene 

 the most wonderful and enchanting I have ever 

 witnessed. 



The fascinating and confusing effect which the 

 appearance of fire at night has on animals is a most 



