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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