SENSE OF DIRECTION. 127 



Finally, there is one other point to which we should like 

 to refer. At the egg-hatching season, or just before it, 

 hermit-crabs, as we have seen, repair to the sea-shore. 

 In many cases, this may involve a migration from possibly 

 miles inland, down mountainous slopes thickly overgrown 

 with dense vegetation ; and only those who have tried to 

 find a way down such slopes when they have lost the 

 proper track, know what this entails. Thus we have the 

 migratory instinct and sense of direction exhibited in yet 

 another animal : and I mention it because it only seems 

 to show how almost hopeless it is to try and explain the 

 actual fact of bird migration, by anything more than the 

 mere vague and convenient term of instinct. We may 

 have some beautiful theories ; but in the end, we always 

 seem to have to come back to this miraculous power 

 which animals possess of " finding their way." 



