6 THE MIGRATION OF BIRDS 



few years ago, pointing out the ingenious dogmas 

 ' void of every firm foundation/' says that " really 

 it is a field in which every thinking ornithologist 

 may create new theses to any extent and more or 

 less incredible" (31). 



Herr Herman's system of " ornithophsenology," 

 the accumulation of substantiated observations and 

 facts, will not prove everything, but his work in 

 Hungary, that of Dr Merriam and Mr Cooke in 

 America, and of Mr W. Eagle Clarke in Britain, 

 each aided by a numerous band of careful workers, 

 are striking examples of what can be accomplished. 

 Whatever errors future enlightenment may show 

 in their conclusions their ascertained facts will 

 remain positive knowledge ; theirs is not what 

 Herr Herman himself described as " pretended 

 authority." 



In order to grasp the problems of migration it is 

 necessary to get rid of the puerile and insular aspect 

 of the subject, namely that migrants are merely 

 those birds which come to us, like the swallow 

 and cuckoo in the spring, and those, like the field- 

 fare and brambling, which visit us in winter but 

 are not with us in summer. The complication 

 of the subject may be demonstrated by a rough 

 classification of the migrants to be observed in 

 the British Islands. 



Arbitrary grouping of the members of an avifauna 



