MIGRATION OF THE YELLOW WAGTAIL. 391 



that that country had already become separated from the main- 

 land. Eastward, however, their range could have no restriction, 

 and doubtless covered all those great lost fenlands and low 

 country formerly uniting England with the continent, including 

 lands also now parts of Belgium and Holland, which we may 

 reasonably suppose were then, as at the present day, locally 

 frequented by them in summer. 



During and subsequent to the invasion of the intruding waters 

 from the north, Yellow Wagtails, in the vernal migration, would 

 pass by the east coast of Spain and along the valleys of the Khone 

 and Seine to the shores of the newly-formed sea, the main body 

 crossing to England, and a narrow stream also following the 

 western shores of the continent to the limit of their range. In 

 the autumn the English Yellow Wagtails, then as now, passed 

 directly south to Africa by the west coast of Europe, and 

 those of the species nesting on the continent may have used the 

 same route — an ancient bird-path which their ancestors had 

 followed for ages — and to reach which they now had to cross a 

 great sea covering no inconsiderable portion of their former 

 summer quarters — an a land passage now turned into f a water 

 passage. A route most circuitous when compared with the 

 obviously more direct and shorter migratory lines followed by 

 M . flava. 



It seems, then, highly probable that this apparently devious 

 and erratic course now followed by M. rail to the east coast of 

 England in the autumn, may be the survival of some very ancient 

 bird-line, still persisted in, although perhaps the necessities, or 

 special causes, which first induced its use may be in abeyance 

 or altogether become obsolete. Undoubtedly these bright little 

 autumn wanderers are, in their own way, telling some very old 

 story, and it remains to ornithologists to try and interpret it. 



In conclusion, we think there is sufficient evidence that large 

 numbers of our English Yellow Wagtails cross from the Con- 

 tinent in the autumn to migrate across England and following 

 a south-westerly line. 



