Many species of stranger ants were killed and carried off as food, but now and then I noted a most significant exception. In three different parts of the glade I saw good-sized, pale, flesh-colored ants which walked unharmed in the very ranks of the terrible host. Unharmed they were, but not wholly above suspicion, and their progress was not an easy one. For every unburdened ant which passed leaped at the pale one, antennaed it fiercely for a moment and reluctantly released it. One could read their indecision as they slowly loosened their hold, turning again and again and waving their antennæ as if to make sure that it was not better to act on their suspicion and slay at once. Finally, they always passed on. The pale ones had some strange inaudible password, some sensory parole which protected them. And their total lack of fear showed their knowledge of their immunity. Even with the added sense of sight which they possessed, they chose voluntarily to accept this dubious, reluctantly accorded friendship. But it was probable that, even if they lived in the very community or nest of the army ants, theirs was the hard-earned dependence of neutrals who were liable to be knocked down at a moment's notice, and searched for any strange, inimical scent which would spell instant death. In one place the army column made a slight détour round a hillock of sandgrains upon which a host of tiny brown ants was laboring. I thought it remarkable that such immunity should be accorded these dwarfs, and I sought the reason. It was forthcoming at once when I gingerly lifted a big soldier with the forceps and dropped him on the ant-hill. What occurred was a replica of the usual army ant scene, but enacted as if viewed through the large end of an opera-glass. Scores of the minute brown chaps rushed forth and for a moment fairly overbore the white-headed giant. Indeed, before he could recover he was dragged partly down a sandy hole. His jaws brandished and champed, but his assailants were so small that they slipped through them unharmed. Many actually seized the jaws themselves and were hurled through the air as they snapped together. Regaining his feet, the great army ant staggered off and, fortunately for him, rolled down a slope into another column of his own kind. Here he freed himself little by little, scraping off the minute fighting browns with the help of two very small workers, whose jaws, being much less in size, were better able to grip the diminutive furies. Their assistance was half-hearted, and the odor of the dead and dying pygmies was distinctly disliked by them. They were apparently well aware of the capabilities of these small cousins, and held them in high respect. This outburst of successful defense on the part of the small ants was unexpected. I glanced back at their hill and saw them unconcernedly piling up grains as if nothing had occurred to disturb them. I wondered if, with senses perfectly attuned, with an