ever, hesitate to set out on their journey, guided only by the organ of distant orientation. The sense of direction, a subjective organ, gave them the direction to be followed, pointed out the reverse of the path of the preceding season. Sight, an objective organ, would have put them on guard against obstacles; in the present instance it was of no use to them. This is why the birds on the church and on the roofs took up their way through the air without difficulty, while their companions, lost in a labyrinth of trees, walls, and houses, did not succeed in freeing themselves from these obstacles.
VI.
We have shown that an animal is restricted to a domain where he finds everything that is demanded for the preservation of himself and of his species. This domain, more or less extensive for the wild beast, is restricted for the pigeon, for example, to the four walls of his cote. In truth does he not find there, to use the apt expression of the fabulist, "good food, a good bed, and everything else?" On the other hand, if it is true that a knowledge of his locality is not absolutely indispensable to insure his return home, and the sense of distant orientation suffices to guide the animal, it will without doubt be admitted that it is possible to make a pigeon house movable and to teach its inhabitants to lead a wandering life.
Let us suppose that a cote is transported into entirely new surroundings without the least disturbance being made in the life of its inhabitants. They, set at liberty on their arrival, will perhaps wander away, but the law of retracement will insure their return. We have remarked above that a lost pigeon knows how to return to the point of his release which he has hardly noticed in the morning and to which apparently no pleasant memory, no interest, attracts him. For still greater reason the dweller in a movable pigeon house would attempt to retrace his journey. If he is taken to some distance and then released, he will go to find his home just where he left it. The movable pigeon house which comes into a new region will therefore render, to some extent, almost immediate service in the locality.
This new way of using the carrier pigeon, impracticable according to the ideas which have hitherto been held with respect to orientation, is only the strict application of our theory.
Interesting experiments have proved conclusively that faithfulness to his native cote can be reconciled with wandering life. A certain number of pigeons were born and raised in a wagon used as a pigeon house. They had no other home than this moving house. It was of little consequence to one of these pigeons whether its house stopped to-day in the bottom of a valley, to-morrow sought shelter in a forest, or stopped for a little while in the maze of houses forming a large city. If it were taken away from its cote to be released, it would not be guided on its return by the necessarily slight knowledge of the region
