100 THE MIGRATION OF BIRDS 



migration would be accelerated through Spain and 

 France towards Britain. 



Mr Stubbs points out that the pathways of several 

 birds, or parties of birds, which started at different 

 hours, would be divergent, for they would come 

 within the influence of winds blowing in various 

 directions according to the position of the system ; 

 this he argues is contrary to the accepted idea of 

 routes. This, however, entirely depends upon what 

 we mean by a route, as I endeavoured to show in an 

 earlier chapter. The journey from point to point 

 is a route, although the bird may be drifted many 

 miles in one direction or another on the way ; it is 

 only when the bird fails to reach its objective, a 

 suitable breeding place or winter station, that the 

 route is a failure. 



The frequent occurrence of rare birds, some of 

 them almost or quite unknown elsewhere in Britain, 

 on out-of-the-way islands, has led to strange theories. 

 One is that there are regular fly-lines over Fair 

 Island, the Flannens, St Kilda and elsewhere, similar 

 to the one which is said to pass over Heligoland. 

 Mr Eagle Clarke's long expected book will contain 

 the ideas of the man who is best able to theorise on 

 this point ; I write, now, with the feeling that his 

 knowledge may lead me to alter my ideas. The 

 suggestion I can offer at present is that there are 

 ornithologists directing their attention to these spots 



