Some curious facts are then given in regard to the uniform direction—varying according to the country—in which these wingless locusts march. The account will be remembered of how a flying host came to the banks of a river which they refrained from crossing. One might almost think that a mistake had here been made, and that the locusts were really _voetgangers_, but had they been so, the river, unless a large one, need not have deterred them—at least, they will pass streams, though doubtless great numbers are sacrificed in doing so. If, however, the stream had run parallel to the direction in which the swarm was advancing, we can understand, in the light of what seems to be now established, their not crossing it. ----- Footnote 18: Dr. Æneas Munro, The Locust Plague and its Suppression. Footnote 19: E. Selous, Bird Watching, pp. 213-15, 271, etc. Footnote 20: Dr. Æneas Munro, The Locust Plague and its Suppression. ------------------------------------------------------------------------ CHAPTER VII The sense of direction—How locusts look flying—Follow no leader—Unanimity of movement—Flight by moonlight—Roosting at night—Extirpated in Cyprus—The “Chinese Wall” system—Not adapted to Australia—Deference to aboriginal feeling—Locusts in Australia—Strange ceremony of egg-laying—Inadequate explanation. IN regard to the faculty of direction with which locusts seem endowed, Dr. Munro says: “The flying locusts in the Argentine come from a northerly direction, and the hoppers or creepers march towards the south, although it might be, so far as abundance of suitable food goes, to their manifest advantage to go in an opposite direction. In certain countries the direction may be known. In this country (South Africa) it will be found that they march towards the south, and not towards the north, east, or west, though either of these directions might have been better for them. The direction may not be true south; it may incline at one time to the south-east, at another to the south-west; but, taken as a whole, it will be southwards.” And he adds: “If proof be needed that the ‘_saltonas_,’ another name—perhaps the Portuguese one—for these wingless armies, march in one direction, it is abundantly found in the experience of the screen and trap, or Cypriote system of destroying locusts, which is based on this fact, and on this alone. This is conclusive demonstration.”[21]