Page:Popular Science Monthly Volume 44.djvu/776

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HEN Sir John Lubbock rotated a paper disk upon which ants were moving in a given direction and the ants turned so as to maintain their course, it seemed as if they were endowed with some mysterious sense or power of direction, like that of a magnetic needle upon its pivot. When he substituted for the plain disk a circular hat-box, which, as he thought, must constitute for an ant the entire visible universe, and still the ants turned as the box was rotated, the fact seemed proved. Ants must have located within their bodies, and independent of ordinary sensory impressions from the external world, the power of going in any direction they wish. This conclusion is far reaching in its consequences. If ants possess such mysterious power, may it not exist in other, or all, animals? It must be of the nature of a special sense. Where, then, is the sense organ? How should ideas of animal sensation be modified by it?

Many writers would have ceased experimenting at this point, and gone off into chapters of ecstatic hypothesis about this fathomless mystery, this unmistakable "sense of direction" developed to such perfection in so humble a creature. Not so with Lubbock. When he covered the hat-box, then rotated it, the ants did not turn, but were turned with the box; or when he shifted the position of his candles to the opposite side, as he rotated the box, the ants did not turn. And so their action fell from the realm of exquisite mystery to take its place among such commonplaces as that of the sailor steering his course by the lighthouse or the stars, or that of a man guided home by the light of his own camp fire.

A considerable literature, pro and con, has gathered about the subject, in which we find frequent use of such expressions as "direction-sense," "sens de la direction," "sense of orientation," "faculté d'orientation" "instinct of location," "magnetic sense," "Orientierungssinne," "Gefühl der Kardinalrichtungen," and many more. By whatever terms designated, the idea is that animals possess some special sense, some occult faculty, by which, without reference to external objects, they are able to guide their movements aright. This power, it is commonly thought, is not possessed, or only in a rudimentary degree, by civilized man, is more highly developed in savages, and may be found in its perfection in certain migratory animals.