It was when the hunting-ants discovered the nests of other species of ants that warfare, true to its name, was waged. One could watch as from a balloon, mimic Waterloos and Gettysburgs, and sad to relate, in the case of inoffensive species, plunder, murder, and abduction by the wholesale. After studying the ways of these merciless creatures, we could seldom walk through the quiet, sunlit jungle, with blossoming orchids everywhere overhead and the songs of birds and pleasant hum of insects in our ears, without thinking of the tragedies without number ever going on around us. Used as we were only to the small lightning bugs of our northern summer nights, the big luminous elater beetles (_Pyrophorus_ sp.) were ever of interest. The two thoracic lights are placed on the outer posterior edges and give out a pale greenish glow of great intensity. We could easily see to read and write by their light, and by placing a half dozen of these insects in a glass we could use them instead of our electric flash. When we examined them carefully we were surprised to find that there was another area of illumination on the abdomen, below and just behind the insertion of the third pair of legs. When fully illuminated this area was brilliant and of a figure ∞ shape. The light however was radically different from that of the thorax, being yellowish, and candle-like, giving an illusory impression of an opening from the incandescent interior of the insect. When the insect settles to rest the only visible illumination is from the pair of thoracic lights, but in flight the abdominal searchlight comes into play, burning brightly with a strong yellowish glare quite different from the green thoracic lights. As we lay at night half asleep we would sometimes be awakened by the droning of one or two big elaters, whose intermittent flashes would illumine the whole room. More than once we had to capture the intruders with the butterfly net and banish them before we could get any sleep. We chloroformed two of these luminous beetles and pinned them in an insect box. Two evenings afterward when we had occasion to add more insects, the box was opened and to our surprise the little lanterns were still aglow and hardly less brilliant than when the insects were alive. They had been dead forty-eight hours and yet their light still shone ghostly white, lighting up the other insects in the box. One evening we found a tiny wire worm, the larva of some small species of elater, which was highly phosphorescent. Although only about one-half of an inch in length, the whole head, the posterior segment and a spot on the side of each of the others was bright. Watched as it moved smoothly and rapidly along, it reminded us of a ship passing at a distance at night with the lights streaming from the port-holes.