Now, high as it may rise to obtain a better view, this questioning staff is surrounded by a narrow and obscure horizon, which future investigations will replace by other horizons more remote and no less obscure. Beyond all these horizons, laboriously torn asunder, one by one, by the progress of knowledge, beyond all this obscurity, what is there? Assuredly, the broad light of day, the wherefore of the why, the reason of reasons, in short the great x of the world’s equation. So says our questioning instinct, ever dissatisfied, never weary; and instinct, which is infallible in the animal domain, should be no less so in the domain of the mind. So far as lies in my power, I have sought to discern the essential motives of the insect’s anomalies. By no means always has the answer brought a firm conviction. And so, to end this chapter, in which so many glimpses remain shrouded in doubt, I set here, plain to see, in the middle of the page, the augur’s lituus, the note of interrogation: ? CHAPTER XIII THE GOLD BEETLES: THEIR FOOD As I write the first lines of this chapter, I think of the Chicago slaughter-yards. Those horrible meat-factories where, in the course of the year, men cut up over a million Bullocks and nearly two million Pigs, which, entering the factory alive, come out at the other end changed into tins of preserved meat, lard, sausages and rolled hams. I think of them because the Carabus, or Ground-beetle, is about to show us a similar swiftness in butchery. I have twenty-five Gold-beetles (Carabus auratus, Lin.) in a large glass vivarium. At present they are motionless, cowering under a bit of board which I gave them as a shelter. With their bellies cooled by the sand and their backs warmed by the board, which is visited by the searching rays of the sun, they slumber and digest their food. By good luck I chance upon a procession of Pine-caterpillars [89] descending from their tree in search of a favourable spot for burial, the prelude to the underground cocoon. Here is an excellent herd for the slaughter-house of the Carabi. I collect them and place them in the vivarium. The procession soon forms again; the caterpillars, about a hundred and fifty in number, move in an undulating line. They pass near the piece of board, in single file, like the Pigs at Chicago. This is the propitious moment. I let slip my wild animals, that is to say, I remove their shelter.