

O O O O 



egarding the criticism, in my opinion there is still one gap 

 left which i purpose to fill up with the map accompanying 

 this paper It shows the Routes of Mi^^ration compiled 

 from various authors, not only from their cartographi- 

 cal publications, but in some cases also according to their 

 written directions, it is only natural that the map is not exhaustive, 

 for two reasons: firstly, because the widely scattered material was not 

 all at my disposal ; secondly, because to draw in all that is noted down, 

 even the local Migration-routes and directions, would have been a Gor- 

 dian Knot, to unravel which the span of life still left to me would 

 be inadequate; and modesty forbade me to employ the method of 

 Alexander the Great, 



The sources for this map are as follows : 



1. *BORGOREVE: „Die Vogelfauna von Norddeutschland". 18Q6.* 



2. *Brehm, Ch. L. : „Der Zug der Vogel". Isis. 1 828., Naumannia 1 855. 



3. DlXON: „The Migration of British Birds". 18Q5. 



* The books marked witli an asterisk coiil.iin ii<> maps. 



(Zl 13 !3J 



