When pigeons were to be sent back and forth, it has been usual to keep two sets, with their respective homes at either end of the course; and when they have reached their home, to carry them back to the places from which they are to be dispatched. An ingenious process has been devised to overcome this difficulty and cause the birds to fly with equal certainty in both directions. Pigeons, for example, whose home is in Paris are confined for several days at St. Denis, and fed there at a stated hour every day with some favorite food which is not given them at their real home. They become in the course of time familiar with their new home and its choice dishes. When set at liberty, they start off at once for Paris, without forgetting the good things they enjoyed at St. Denis. When they are to be sent back, they are made to fast a little while, and are then let loose at about feeding time at St. Denis. They go thither, and, when they have their own way, time their going so as to be there at the exact moment of feeding. Birds have thus been taught to fly back and forth regularly between places thirty miles apart.
When a carrier pigeon is set at liberty at a distance from its home, it rises in the air, describing a spiral, higher and still higher, then takes a start. In about a quarter of an hour it will be seen again directly above the point at which it was freed. It starts thence anew, and takes the right direction without hesitation. Compare this quickness of decision with the embarrassment experienced in a strange region by an intelligent man who has read up about the country and is fortified with all the knowledge concerning it that science can give him!
The sense that guides the pigeon in its direct return to its home is as much a mystery as it ever was. It is not sight, for the bird at its highest flight can not command the vision of a single familiar object or place. Theories of electric currents have been imagined and other methods of analyzing and explaining the instinct have been devised, but they are all alike conjectural and insufficient. But while we do not know the cause or the method of the faculty, we have it in our power to modify and direct it in a certain degree. To the wild pigeon, which goes far in search of food, the power to find its way back to its nest is a necessary condition to its existence. The domestic pigeon does not have to go long journeys for food, but its return home is nevertheless determined by this question. The best fliers are those which are least competent to pick up anything to eat on the road. The sense of orientation—the homing sense—has been cultivated and bred in them at the expense of other faculties which have become less useful to them. While very poorly armed to contend with the conditions of a wild state, the carrier pigeon is perfectly equipped for its present conditions of existence and for the services that
