Eciton praedator.--This is a small dark-reddish species, very similar to the common red stinging-ant of England.It differs from all other Ecitons in its habit of hunting, not in columns, but in dense phalanxes consisting of myriads of individuals, and was first met with at Ega, where it is very common.Nothing in insect movements is more striking than the rapid march of these large and compact bodies.Wherever they pass all the rest of the animal world is thrown into a state of alarm.They stream along the ground and climb to the summits of all the lower trees, searching every leaf to its apex, and whenever they encounter a mass of decaying vegetable matter, where booty is plentiful, they concentrate, like other Ecitons, all their forces upon it, the dense phalanx of shining and quickly-moving bodies, as it spreads over the surface, looking like a flood of dark-red liquid.They soon penetrate every part of the confused heap, and then, gathering together again in marching order, onward they move.All soft-bodied and inactive insects fall an easy prey to them, and, like other Ecitons, they tear their victims in pieces for facility of carriage.A phalanx of this species, when passing over a tract of smooth ground, occupies a space of from four to six square yards; on examining the ants closely they are seen to move, not altogether in one straightforward direction, but in variously spreading contiguous columns, now separating a little from the general mass, now re-uniting with it.The margins of the phalanx spread out at times like a cloud of skirmishers from the flanks of an army.I was never able to find the hive of this species.
Blind Ecitons.--I will now give a short account of the blind species of Eciton.None of the foregoing kinds have eyes of the facetted or compound structure such as are usual in insects, and which ordinary ants (Formica) are furnished with, but all are provided with organs of vision composed each of a single lens.
Connecting them with the utterly blind species of the genus, is a very stout-limbed Eciton, the E.crassicornis, whose eyes are sunk in rather deep sockets.This ant goes on foraging expeditions like the rest of its tribe, and attacks even the nests of other stinging species (Myrmica), but it avoids the light, moving always in concealment under leaves and fallen branches.When its columns have to cross a cleared space, the ants construct a temporary covered way with granules of earth, arched over, and holding together mechanically; under this, the procession passes in secret, the indefatigable creatures repairing their arcade as fast as breaches are made in it.
Next in order comes the Eciton vastator, which has no eyes, although the collapsed sockets are plainly visible; and, lastly, the Eciton erratica, in which both sockets and eyes have disappeared, leaving only a faint ring to mark the place where they are usually situated.The armies of E.vastator and E.
erratica move, as far as I could learn, wholly under covered roads-- the ants constructing them gradually but rapidly as they advance.The column of foragers pushes forward step by step under the protection of these covered passages, through the thickets, and upon reaching a rotting log, or other promising hunting-ground, pour into the crevices in search of booty.I have traced their arcades, occasionally, for a distance of one or two hundred yards; the grains of earth are taken from the soil over which the column is passing, and are fitted together without cement.It is this last-mentioned feature that distinguishes them from the similar covered roads made by Termites, who use their glutinous saliva to cement the grains together.The blind Ecitons, working in numbers, build up simultaneously the sides of their convex arcades, and contrive, in a surprising manner, to approximate them and fit in the key-stones without letting the loose uncemented structure fall to pieces.There was a very clear division of labour between the two classes of neuters in these blind species.The large-headed class, although not possessing monstrously-lengthened jaws like the worker-majors in E.hamata and E.drepanophora, are rigidly defined in structure from the small-headed class, and act as soldiers, defending the working community (like soldier Termites) against all comers.Whenever Imade a breach in one of their covered ways, all the ants underneath were set in commotion, but the worker-minors remained behind to repair the damage, while the large-heads issued forth in a most menacing manner, rearing their heads and snapping their jaws with an expression of the fiercest rage and defiance.
