It seems difficult to understand how it comes that these galls are systematically placed among the seeds, for it was evidently no chance occurrence, and I can only conjecture that the worker ants may have brought them in and stored them under the impression that they were really seeds! Even ants make mistakes, and of this I have given an example above (p. 19). Though I have frequently found colonies of several distinct species of ants inhabiting nests made in the earth traversed by the widespread galleries of Atta structor and barbara, I have never detected any inter-*mixture of species in the chambers of a nest,[1] and but rarely found even the galleries and entrance used in common by more than one species. On one occasion when opening a nest of structor I cut through a colony of the tiny, large-headed, yellow ant Pheidole megacephala, lying in the midst of, though distinct from, the former. When, however, it chanced that one of the structors fell from the crumbling earth into the midst of the Pheidoles, it was curious to see how fiercely it would be attacked, and with what terrified speed it would scamper off, without attempting any resistance, and often carrying two or three Pheidoles hanging on to its legs.
Accidentally in this way battles do sometimes take place between ants of different species; but by far the most savage and prolonged contests which I have witnessed were those in which the combatants belong to two different colonies of the same species.
- ↑ Except in a few cases where I have seen one or two structors in nests of barbara and vice versâ, and in the curious instance to be mentioned below, where one colony consisted of nearly equal parts of structor, barbara, and the red-headed variety of barbara.
