THE LAWS OF ORIENTATION AMONG ANIMALS. 487 



sulliciently proven aiicl let us make use of it to explain certain facts, 

 inexplicable by any other means. Let us imagine that we are present 

 at a release of pigeons. Many hundreds of birds coming from cotes in 

 the same region are set at liberty at the same time. They set out 

 together, separate to travel in two or three groups. Then as soon as 

 they reach the horizon to which they are accustomed each flies straight 

 to its own home. 



A certain number of pigeons do not return, others come in on the 

 following days. The owner merely registers the losses and notes the 

 tardy ones without trying to discover the cause of the failure in instinct. 

 In truth, how can we ask for the secret of a bird which, with one stroke 

 of its wing disappears from our view. Its instinct is at fault; the bird 

 must then wander at will, counting on chance to find its way home. 



We can not agree to this proposition for the following reasons: The 

 bird that has gone astray through a defect of instinct is still, neverthe- 

 less, not beyond the control of that general law of self-preservation 

 which guides all its actions. On the contrary, it feels strongly the call 

 of instinct which incites it to return to its own cote. It sees clearly 

 the end, but the means of attaining it are for the moment at fault. It 

 displays then all the voluntary activity of which it is capable, trying 

 path after path successively. The law of retracement will permit us to 

 follow it in its wandering course and to retrace its journey. When we 

 have found out the secret of the lost pigeon we shall realize again that 

 chance plays a very small part in the decisions of animals. 



In 1896 we were present at Orleans when a number of pigeons from 

 the cotes at Mons and Charleroi were released. The two bands of pig- 

 eons having by chance been set free at the same time, at two different 

 points in the freight station, joined each other in the air and formed at 

 their departure a single group. The weather was extremely unfavor- 

 able. Fog, rain, and contrary wind contributed to delay the return of 

 the winged voyagers. One first mistake in instinct, easy to explain, 

 was made at the outset. Two pigeons from Mons were taken in at 

 Charleroi and three from Charleroi were received at Mons. Besides 

 about forty pigeons did not return home on the evening of their release. 

 They had, however, left Orleans together. The birds which first returned 

 had pointed out to their companions the proper road and some of the 

 latter had followed their guides blindly, even so far as to enter strange 

 cotes. 



But in Orleans an observer remarked that between 3 o'clock in the 

 afternoon and 7 in the evening about thirty pigeons flew up and rested 

 on the roof of the station. When night came we succeeded in captur- 

 ing niue; five were from Charleroi and four from Mons. They were 

 again set at liberty. This observation leads us to suppose that the 

 thirty-two pigeons that returned to Orleans had all gone astray from 

 the group released that morning. The next morning between 5 and 7 

 o'clock they all disappeared one after another toward the north; about 



