AMERICAN ORNITHOLOGY. 
COOPER’S HAWK. 
FJ1LC0 COOPERII. 
Plate X. Fig. 1. 
Philadelphia Museum , No. 403. 
My Collection. 
Buffon complained of the difficulty of writing a history of Birds, 
because he already knew eight hundred species, and supposed 
that there might actually exist fifteen hundred; or even, said he, 
venturing as he thought to the limit of probability, two thou¬ 
sand ! What then would be his embarrassment at present, when 
nearly six thousand species are known, and fresh discoveries 
are daily augmenting the number? 
The difficulties attending a general work on this subject are 
not perhaps experienced in an equal degree by one who confines 
himself to the history of a particular group, or of the species inha¬ 
biting a single district. Nevertheless, in a work like the present, 
which is not a monography limited to one genus or family, but 
embraces within its scope species belonging to all the different 
tribes, it is requisite, in order to explain their various relations 
VOL. II.—A 
