to his home by all five senses working together. Always, in every species, one of the senses is more developed than the rest, and therefore plays a more prominent part in the act of orientation—sight for the bird, scent for the dog, etc.
If orientation within restricted limits is easily explained by the combined play of the five senses, it is not so as regards orientation in an unknown and distant territory. Let us cite an examine: In order to lose a cat you put him in a bag and carry him by railroad a distance of 80 kilometers. Set at liberty he returns to his home. Though his sight and his local knowledge guided him constantly back to his home after his daily wanderings, he yet will not know how to make the same use of them on this occasion. His sight, were it excellent, could not be a great help to him, as the slightest obstacle, the most insignificant rise in the ground, would be sufficient to hide the familiar landscape. Is it, then, his sense of smell that guides him? In this case precautions seem to have been carefully taken to put this sense at fault. One fact, however, remains—we are going to try to explain it—the cat has easily returned to his home.
Let us take another example: The pigeon fanciers of Brussels every year let loose pigeons at Bordeaux. In preparation for this they make three successive releases, at increasing distances, between Brussels and Orleans, consequently towards Bordeaux, then after the release effected at Orleans, without further preparation, the pigeons are set at liberty at Bordeaux and they return to Brussels. Can we attribute their return to a memory of the locality, to a piercing vision? Let us admit that in the three preparatory flights the pigeons may have remarked certain prominent landmarks between Brussels and Orleans. At the time when they were let loose at Bordeaux, the elevation of the land, the rotundity of the earth, set limits to their vision, however piercing it might be. To see Orleans from Bordeaux the pigeon would have to rise several kilometers above the earth, which would be physically impossible.[1]
Let us cite another case: Some pigeons belonging to a pigeon fancier in Orleans had traveled in the direction of Reims. Some one conceived the idea of releasing them 500 kilometers out to sea beyond Nantes, without any preparation, and they almost all returned. In this example, as in those preceding, the return can not be explained by the working of any one of the five senses. It is therefore necessary to acknowledge the intervention of a distinct organ serving for orientation from a distance. Since the function exists, we are not illogical in supposing that there is, corresponding to that function, an organ which we will call the sense of direction.
We therefore admit that orientation near at hand is easily explained as the use of the five senses, and that orientation from a distance rests solely on the working of a sixth sense.
- ↑ Pigeons rarely fly at more than 300 meters above the ground. Set at liberty from a balloon more than 2,000 meters high, they descend with a dizzy rapidity, letting themselves fall, and not resuming their flight until near the earth.
