254 THE MIGRATION OF BIRDS. 



on our eastern seaboard until almost bewildered by 

 the steady throbbing rush, rush, of arriving birds. 

 Thrushes, Larks, Goldcrests, Finches, Starlings, 

 Crows, Rooks, and Ring Doves comprise the bulk 

 of these migrants ; but many other species arrive 

 in smaller numbers, and now and then a rare 

 straggler whose route has been abnormal. It is very 

 interesting to trace the approach and arrival of these 

 great Bird Waves, advancing from the continent 

 to our Islands. Here, for instance, is the move- 

 ment of a very important wave from east to west 

 during the night of October 15 — i6th, 1885, traced 

 from Heligoland across the North Sea to the 

 British Islands. We find Gatke at his island 

 station of Heligoland making a note, referring to 

 the morning of the 15th, that the weather was 

 favourable for an important migration — Thrushes 

 and Woodcocks especially — the wind S.E., the 

 weather clear ; but owing to the strong westerly 

 currents prevailing in the higher atmosphere, the 

 impending flight did not take place, or was not 

 visible from the island. In the evening the wind 

 rose and changed to E. by N., with clouds from 

 the S. and E., whilst in the night it backed to the 

 E. with thick clouds from the S.E. During the 

 day, however, Jackdaws and Hooded Crows, as well 

 as Thrushes, Pipits, Larks, Buntings, Jack Snipes 

 and Chaffinches were observed on passage, the 

 latter birds flying in thousands, but so high as to 

 be invisible, and only distinguished by their notes ; 

 in the night the impending bird stream passed by, 



