RESEARCHES IN ZOOLOGY. 
ON 
THE MIGRATION OF BIRDS. 
—>— 
Aw accurate and comprehensive history of the Peri- 
odical Birds may now be considered one of the 
greatest desiderata in ornithology. Hitherto little 
has been done to elucidate the manners and economy 
of this interesting portion of the feathered tribes, as 
connected with their periodical appearance and dis- 
appearance ; for although much has been written on 
the subject, yet few facts of any considerable import- 
ance have been ascertained; and even those few lie 
scattered through the writings of such various authors, 
and are so blended with what is erroneous or merely 
conjectural, that it is no easy task to distinguish and 
collect them: consequently our knowledge of the 
circumstances which regulate the motions of the 
B 
