DIRECTION OF THE MIGRATION FLIGHT 33 



land. The autumn migration of all these birds must of necessity 

 proceed in a southerly direction. 



The flight of these migrants has thus been followed from 

 eastern Asia to the Atlantic shores of Europe. In the case of the 

 most different species, and in districts so widely separated as central 

 Germany, Heligoland, the eastern coast of Great Britain including 

 the Orkney and Shetland Islands Norway up to a latitude of 70 

 N., in Finmark, the same results as to the direction of the migratory 

 flight have been obtained. The latitudinal range of this migration 

 front covers a stretch of no less than 960 geographical miles ; and 

 we may therefore consider as established, the view previously 

 expressed, that a large, if not the largest, number of our autumn 

 migrants pass over the longest stretch of their migratory journey in 

 a direction from east to west ; that while some may for a time change 

 this course for a southerly one, the majority do not turn to the south 

 before the termination of their westerly flight, and that in these move- 

 ments they are entirely uninfluenced by the appearance and physical 

 characters of the immense surface of continent they traverse. 



In this long ' wave of migration,' however, each of the many 

 hundreds of species which compose it does not follow a migration 

 route, more or less narrowly limited, of its own, but all on setting 

 out from the breeding area take up a westerly course which, within 

 the latitude of their nesting stations, they pursue to its final goal, 

 some making temporary digressions to the south in the course of 

 the journey, others not turning south until the concluding stage of 

 their migration has been reached. 



Of course it may happen that some fraction or other of a 

 broad migration column, having got over a line of sea-shore lying 

 far below its path, may continue its flight uninterruptedly along 

 the same, but this is only because geological conditions have given 

 the shore-line a course corresponding to the direction of the migra- 

 tion movement, either from east to west or north to south, and 

 ought in no sense to be attributed to any plan or purpose on the 

 part of the wanderers. 



In order to show the fallacy of such an assumption, we need 

 only to examine afresh, and somewhat more closely, the migration 

 route of Richard's Pipit, and of the many other species from 

 eastern Asia, which visit Heligoland in such large numbers every 

 autumn. All these birds cover the immense distance from the other 

 side of Lake Baikal to the eastern extremity of Prussia without the 

 aid of any of the alleged road-marks or guide-posts : are we, there- 

 fore, to assume that when arrived at the Baltic, they suddenly become 

 utterly incapable of continuing their journey, except by following 

 the comparatively small span of coast to Holstein ? And when, 



