National Geographic : 1970 Jul
EKTACHROME BYNATIONALGEOGRAPHIC PHOTOGRAPHERROBERTF. SISSON Railroad worms usually turned on all their lamps when I first touched them. The glow began to diminish slowly after perhaps a minute, and eventually went out. Their ner vous system, I learned, can switch individual lights on and off. I have seen them dim and brighten their side lights, extinguishing one or a pair while others shone intensely. And I watched one that repeatedly turned on the red, but not the greenish-yellow. In captivity their behavior changed. Al though the larvae had ignored exploding fire works and stamping feet in their own world, they lit up readily in the unfamiliar environ ment of my hotel room. I could make a dozen 62 stage a veritable festival of lights by tapping my fingers on the dresser, where I kept each in a plastic jar. (I had learned that when sev eral are confined together in a small space, one sometimes attacks and even eats another -although I never saw evidence of this in their wild state.) Even the closing of a door across the room would turn their lights on. Captive larvae lit up brilliantly as they attacked the millipedes that I offered as food. Curling about the victim's body, the rail road worm would bite into the midsection. It seems to secrete or, perhaps, regurgitate a dark fluid-it may be a poison or a stomach en zyme-as it sinks its sharp, scimitar-shaped N.G.S.