Why our British fireflies are designated "glow-worms" is difficult to understand. _Lampyris noctiluca_ has nothing worm-like about it. It is a true insect. The popular misconception has probably arisen in this wise. The female glow-worm, the light-giver, is wingless; the male is winged. The latter, however, has but little of the light emitting power possessed by the female. Only the light-givers are collected, and being destitute of the first attribute of an insect, wings, are set down in popular parlance as worms. Old mossy banks, damp hedgerows, and shaded woods are the loved haunts of the fireflies, and the warm nights of the soft summer months most induce them to burn their soft lustre. Some widowed worm or firefly flirt may shed her luminous self in the darkness even on into dying summer or autumn. But this is unusual. It is not definitely known what purpose is served by the emission of the soft green light, but it has long been suspected that the lustre was to attract the male. Gilbert White found that glow-worms were attracted by the light of candles, and many of them came into his parlour. Another naturalist by the same process captured as many as forty male glow-worms in an evening. Still another suggestion is that the phosphorescence serves for a protection or means of defence to the creatures possessing it, and an incident which seems to support this view has been actually witnessed. This was in the case of a carabeus which was observed running round and round a phosphorescent centipede, evidently wishing but not daring to attack it. A third explanation of the phenomenon is that it serves to afford light for the creature to see by. A somewhat curious confirmation of this is the fact that in the insect genus to which our British fireflies belong, the _Lampyridæ_, the degree of luminosity is exactly in inverse proportion to the development of the vision. Fireflies glow with greatest brilliancy at midnight. Their luminosity is first seen soon after dark: "The glow-worm shows the matin to be near, And 'gins to pale his ineffectual fire."