The most wonderful of all the fire-beetles is the large one of near two inches long—quite, or more, if we count the antennæ—that inhabits Mexico, where in ancient times it was used as a lantern by the Aztecs in their night-journeys, as it still is by their modern descendants. It is wonderful, not by reason of its size merely, or, in any special degree, of the light it emits—though this is brilliant in proportion to it—but because it carries three separate lamps: two above, situated on either side of the thorax, and one on the under side, just in front of the abdomen. Thus, as it turns or varies in its flight, one flash of the most intense brilliancy follows another, like the revolving light of a lighthouse. The colour of the light is described as a rich green—richest, however, or at least brightest, on the under surface.[151] The beauty and dazzling effect of this upon a dark night can be imagined, and is thus described by Dr. Kidder: “Before retracing my steps I stood for a few moments looking down into the Cimmerian blackness of the gulf before me; and while thus gazing a luminous mass seemed to start from the very centre. I watched it as it floated up, revealing in its slow flight the long leaves of the palm _Euterpe edulis_, and the minuter foliage of other trees. It came directly towards me, lighting up the gloom around with its three luminosities, which I could distinctly see.”[151] There is something wonderfully poetical in the thought of winged beings like this pursuing each other through the night, by the light of these glorious flashes—the “light of their own loveliness,” it may well be called, since it is, indeed, their beauty. If seems curious and a waste that where there is the greatest capacity of poetic imagination we should find the least, or almost the least, realisation of it in habit and structure. We know from Oviedo that the Mexican Indians, when they travelled at night, were accustomed to fasten these great refulgent beetles on their hands and feet, and thus pass flaming through the country. They danced, too, by their light, and even wove or painted by it. Why, therefore, could not lamps of great power, as well as beauty, be evolved from such insects by bringing the selective agency of man to bear upon them? The phosphorescent principle in living nature has not perhaps been made the most of by us. Was more made of it by the Aztecs? and did they turn their attention to the systematic rearing of these living lamps?—for, from hearing so little about them one would not think that these insects were so useful now, as, from the above account and what other contemporary Spanish writers tell us, it would seem that they were, at the time of this old and cruelly destroyed civilisation.