132 ■ THE UNIVEESE. 



females; the bees themselves know this perfectly, as we 

 shall see. 



To all these marvels of insect life we mnst yet add the 

 inexplicable phenomenon of the dazzling light which they 

 project into the midst of darkness, and which sometimes 

 in their flight fmTows the air Avith long streams of fire, 

 sometimes peacefully illuminates the foliage on which 

 they repose. 



Every person knows the Lampyris, a glowworm which 



7B. Glowworm male and female — Lampiiris noctiluca. 



in tlie autumn gives our green turf the appearance of a 

 starry heaven. But in tropical America there are phos- 

 phorescent insects of far superior splendour. The great 

 lantern-fly can supj^ly the place of a lamp with the bright 

 light witli which its monstrous head gleams. Sybille de 

 Merian relates that at Surinam she sometimes read the 

 newspapers by the aid of a single one of these Hemiptera.^ 

 In the Antilles the phosphorescence of these insects is 

 even made daily use of; they employ there a luminous 



^ As is the case with so many vital ]ilienomeiia, tlie phos|)horescence of insects 

 is still far from being explained. Sir Humphrey Davjr and Treviraims attributed 

 it to a substance containing phosphorus, wliicli is secreted from the fluids of the 

 animal, and beams like this substance by means of the oxygen c>f the air. This 

 wouhl be a true combustion. The presence of phosjjhoric acid in tlie atmosphere 

 seems to give a certain amount of authority to tliis hypothesis. A German 

 anatomist, the celebrated Carus, discovered that the eggs of these animals are 

 themselves luminous — a very curious fact, and of a nature to throw some light 

 upon the question. 



