On a warm August evening, stretched out in wicker chairs across a porch, everybody is trying to remember which stars belong to the Little Dipper, way up there, when suddently out of the blackness another sort of constellation appears: those first-magnitude stars on earth -- fireflies. No memory of childhood remains more vivid.
Is there any summertime sight more mysterious, and more heart-stirring, than the pulsing glow of photinus pyralis?m Entomologists -- for the firefly is, in fact, a beetle -- tell us the light gets triggered in the lower abdomen. The firefly's signal has as much as one-fiftieth the power of a candle, yet the ratio of heat is one to 80,000. There are more spectacular illuminators in nature than the firefly. For instance, the South American glowworm boasts a red light on its head and row of greenish lights on its sides, earning it the nickname of "railroad worm." But no light in this world is cooler than the light of the firefly, and this cool fire -- this nonconsuming fire -- fascinates us children of Prometheus.
Scientists at Johns Hopkins and elsewhere have been trying to understand how the fireflies do it, blinking like tiny synchronized lighthouses in the night. The process can be partially described in terms of oxygen and enzymes, but the why escapes.
What does it all mean, this deviceful attention-getting of the firefly? -- played out to rhythms as precise as a string sector under Arturo Toscanini. In the first place, we do know that when, say, a two-second interval occurs between flash and flashback, then a courting through light-language is taking place -- a sort of wooing by firefly's Morse code.