Estuaries and tidal creeks, which, as we have seen, are included in the habitat of these water-bugs—at least, of the giant one—bring us gradually to the sea. That there are marine insects we know, but they do not appear to extend beyond the tidal beach, on the sands of which they expatiate, when the sea is out, and burrow into them on its return. All are small, and still smaller is the amount said about them, even in such works as are precisely those where all that is known on the subject ought to be stated—systematic works of natural history, for instance, which take “_Arthropoda_ (Insects, etc.)” in their due order, but do not so much as tell you whether marine ones exist or not. Yet the date of such works is after 1895. For these reasons, and another which has been once or twice before alluded to, I have but one remark to make about marine insects, and I will make that in the next chapter. ----- Footnote 143: Mémoires du Muséum, vols. 18-20. Footnote 144: Entomologist, vol. 14 (1881), p. 82. Footnote 145: Quoted in The Insect Book, by Leland O. Howard. ------------------------------------------------------------------------ CHAPTER XXV One remark—Phosphorescent insects—Glow-worms and fire-flies—Fiery courtship—A beetle with three lamps—Travelling by beetle-light—The great lantern-fly controversy—Is it luminous?—Madame Merian’s statement—Contradictory evidence—A Chinese edict—Suggested use of the “lantern”—Confirmation required—Luminous centipedes. NO marine insect—this is the remark—is phosphorescent—that is to say, as far as I know, which is a very saving clause indeed. This seems curious, because, as everyone knows, other sea-dwelling creatures are, producing most wonderful and beautiful effects, and, moreover, the luminous property is active in many terrestrial insects. Of these the glow-worm is a familiar and, though, perhaps, the humblest, a very beautiful example. At any rate, there are insects of the glow-worm family whose fires are far less “ineffectual,” or, to speak more truly, far outglow those of our own species. What, for instance, can be more gorgeous than the green or orange lights—for they differ in colour according to the sexes—with which the nights and the rich vegetation of the West Indies are brilliantly, yet softly, lit up? Nothing, surely, if it be not the name of the creature producing such splendour, which is _Pygolampis xanthophotis_[146]—not one syllable less.