accomplish in the field of Ornithophaenology, brought me face to 

 face with the three questions above mentioned and I determined to 

 ,,take the bull by the horns" and to settle the question of method, 

 at least in its general outlines. 



It is quite natural that I could not even think of working 

 out the whole of the enormous material known, but it occurred to 

 me that the material relating to Hungary could be sifted and that 

 thus there was a possibility of getting this latter at least in order. 



Assuming that the Congress held in 1891 was, for Hungary, 

 a turning-point, I called all data gathered previous to 1891 his- 

 torical data, while those which were methodically collected for 

 the Congress, I assumed as recent data which could be treated 

 side by side with the historical ones. 



The other points of view were the following : I assumed the 

 migration of birds to be a true phaenological phenomenon, orga- 

 nically connected with Meteorology, so that in Ornithophaenology, 

 too, the geographical coordinates afford a firm ground; that further 

 the hypsometrical conditions - height above the level of the sea 

 - and the orographical features as a whole must be taken into 

 account; that in observation the chief stress must be laid upon 

 the most salient palpable moments, viz. earliest arrival, latest 

 arrival, earliest departure, latest departure; that the time difference 

 between the two must be considered as fluctuation ; and that the 

 mean figures established by this method will throw light upon 

 the whole area under observation and the mutual relation existing 

 between the different points of observation. 



It at once occurred to me that the relative differences of various 

 areas would be perceptible also and would be more pronounced 

 according to the relative distances of the same, a fact which is proved 

 by the migration of birds as a phenomenon of movement; that 

 also the relations between different areas will be recognizable in 

 such a way and that the difference would be the more apparent, the 

 farther they are one from the other. 



I had no doubt that the conditions in Hungary would come 

 out plainly, because the country is excellently articulated, it being 

 split up into one vast plain, one vast hilly portion (Transdanubian 

 district), one large plateau (Transylvania) and an extensive Alpine 

 district (Northern Hungary), thus a whole consisting of clearly 

 defined parts. 



