CHAPTER XII 



THE MIGRATION OF BIRDS 



The Lighthouse on Heligoland (after Seebohm). 



Scanty knowledge of the subject Summary of observations by 

 Mr. W. Eagle Clarke Gatke's observations in Heligoland 

 Migration in the Mississippi Valley Migration in the North Sea 

 Mr. Abel Chapman's remarks on the flight of birds. 



THERE is no subject in the ornithological world about 

 which people speak and write so glibly as on the " Migration 

 of Birds," and yet there is no branch of Natural History of 

 which less is really understood. Those who have laboured 

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