MIGRATION OF BIRDS 5 



' lumpers/' will eventually solve many of the 

 problems of to-day. 



The ancients a usefully ambiguous term 

 realised that birds migrated ; our immediate fore- 

 fathers of two or three centuries ago realised that 

 certain birds vanished in winter and wondered how ; 

 and within modern times the phenomena of migra- 

 tion, the ' mystery of mysteries/' has been the 

 subject of much study, speculation, and literary 

 exposition. Indeed a full bibliography of migration 

 would be a considerable volume. Even workers 

 within the last few years have declared that certain 

 phenomena were beyond human understanding, 

 only to be explained by instinct, a word capable of 

 most varied interpretation. In truth there is much 

 to learn, much to which we must still answer we 

 do not know ; but the speculative theory of yester- 

 day is now either myth or fact, and the theory of 

 to-day may be proved true and add something to 

 the data of which knowledge is built. The wildest 

 speculations, based on slender locally ascertained 

 facts or on no foundation whatever except the 

 fertility of the brain, have been offered as solutions 

 of the mysteries ; the literature of migration is a 

 jumble of contradictions. John Legg, in 1780, 

 said ' ' In relating so many instances of unparalleled 

 credulity, I confess I cannot suppress the irascible 

 passion' (33), and Herr Otto Herman, only a 



