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XXIII. — List of Birds observed in the Zetland 
Islands, 
By Laure]^ce EdmonIjston, Esq, 
Corresponding Member of the Wern. Nat. Hist, Soc. 
(Read Idth November 1821) 
The utility of zoological topography, in enlarging oiir 
acquaintance with the habits and distinctions of animals^ 
and in displaying the nature and extent of those externa! 
circumstances, which often so powerfully change and mo» 
dify them, has been too long acknowledged to be now in» 
sisted on. Without it^ aid, anomalies, in the manners and 
appearances of different species, will often baffle the sd-ga^ 
city of the naturalist, and, perhaps in his uncertainty and 
dilemma, tempt him precipitately to take refuge in the mbst 
fallacious conclusions. Hence one fertile source of the oh^ 
^curity which so long enveloped some df the most interest^' 
ing aiid elevated provinces of zoology, — the errdnedtis 
multiplication of new species, bti the one hand,— and their 
equally unfounded abridgment, on the other. 
