There can be no doubt they are a serious pest, and that the Brazilian Government is well advised in offering a prize of five hundred pounds for some effectual method of extirpation.  It is certain too that since they first appeared in the hills beyond Badama, about three years ago, they have achieved extraordinary conquests.  The whole of the south bank of the Batemo River, for nearly sixty miles, they have in their effectual occupation; they have driven men out completely, occupied plantations and settlements, and boarded and captured at least one ship.  It is even said they have in some inexplicable way bridged the very considerable Capuarana arm and pushed many miles towards the Amazon itself.  There can be little doubt that they are far more reasonable and with a far better social organisation than any previously known ant species; instead of being in dispersed societies they are organised into what is in effect a single nation; but their peculiar and immediate formidableness lies not so much in this as in the intelligent use they make of poison against their larger enemies.  It would seem this poison of theirs is closely akin to snake poison, and it is highly probable they actually manufacture it, and that the larger individuals among them carry the needle-like crystals of it in their attacks upon men.

Of course it is extremely difficult to get any detailed information about these new competitors for the sovereignty of the globe.  No eye-witnesses of their activity, except for such glimpses as Holroyd’s, have survived the encounter.  The most extraordinary legends of their prowess and capacity are in circulation in the region of the Upper Amazon, and grow daily as the steady advance of the invader stimulates men’s imaginations through their fears.  These strange little creatures are credited not only with the use of implements and a knowledge of fire and metals and with organised feats of engineering that stagger our northern minds—­unused as we are to such feats as that of the Sauebas of Rio de Janeiro, who in 1841 drove a tunnel under the Parahyba where it is as wide as the Thames at London Bridge—­but with an organised and detailed method of record and communication analogous to our books.  So far their action has been a steady progressive settlement, involving the flight or slaughter of every human being in the new areas they invade.  They are increasing rapidly in numbers, and Holroyd at least is firmly convinced that they will finally dispossess man over the whole of tropical South America.

And why should they stop at tropical South America?

Well, there they are, anyhow.  By 1911 or thereabouts, if they go on as they are going, they ought to strike the Capuarana Extension Railway, and force themselves upon the attention of the European capitalist.

By 1920 they will be half-way down the Amazon.  I fix 1950 or ’60 at the latest for the discovery of Europe.

  XXXI.

  THE DOOR IN THE WALL.