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Page:Popular Science Monthly Volume 19.djvu/844

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THE POPULAR SCIENCE MONTHLY.

abstracting an individual from it. "News of the disturbance was quickly communicated to a distance of several yards to the rear, and the column at that point commenced retreating." It was also this species that the same naturalist describes as enjoying periods of leisure and recreation when they call a halt in "the sunny nooks of the forest."

On such occasions,

the main column of the army and the branch columns were in their ordinary relative positions; but, instead of pressing forward eagerly and plundering right and left, they seemed to have been all smitten with a sudden fit of laziness. Some were walking slowly about, others were brushing their antennae with their forefeet; but the drollest sight was their cleaning each other. ... It is probable that these hours of relaxation and cleansing may be indispensable to the effective performance of their harder burdens; but, while looking at them, the conclusion that they were engaged merely in play was irresistible.

E. prædator differs from the others of its genus in not hunting in columns, but "in dense phalanxes consisting of myriads of individuals."

Nothing (says Bates) 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 summit 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.

A phalanx occupies from four to six square yards of ground, and the ants composing it do not move "altogether in one straightforward direction, but in variously spreading contiguous columns, now separating a little from the general mass, now reuniting with it. The margins of the phalanx spread out at times like a cloud of skirmishers from the flanks of the main army."

Two species of Eciton are totally blind, and the habits of these differ from those above described in that they march exclusively under covered roads or tunnels. The van of the column is constantly engaged in rapidly constructing the tunnels through which the army or regiment advances as quickly as they are made. Under the protection of these covered ways the ants travel at a surprising rate, and, when they reach a rotten log or other promising hunting-ground, they pour into all the crevices, etc., iii search of prey. Bates says:

The blind Ecitons, working in numbers, build up simultaneously the sides of their convex arcades, and contrive, in a wonderful 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 labor between the two classes of neuters in these blind species. The large-headed class . . . act as soldiers,