278 WHITE-TAILED HAWK. 
For, even admitting several centres of creation, we cannot 
believe that Nature,* who, notwithstanding her luxuriant abun- 
dance, evidently accomplishes all her ends with the greatest 
economy of means, has ever placed, aboriginally, in different 
parts of the globe, individuals of the same species, but has 
always given to each the power of extending its range accord- 
ing to volition, in any direction where it should find climate, 
food, or other circumstances most appropriate. 
The white-tailed hawk is one of those anomalous species 
which connect the generally received divisions of the great 
genus Falco. It participates in the form and habits of the 
kites (AZilvus), while in its other relations it approaches the 
true falcons (Falco), and at the same time presents traits 
peculiar to itself. Savigny has, therefore, very properly con- 
sidered its near relative, the black-winged, as the type of a 
peculiar group, which he elevates to the rank of a genus, but 
which we for the present shall adopt as a subgenus only. 
Subsequent observations have confirmed Le Vaillant’s opinion 
that the swallow-tailed hawk (Falco jfurcatus) is closely 
related to it; and associated with a few other recently dis- 
covered species, they have been considered as a distinct group, 
under Savigny’s name of Hlanus. Vieillot adopted the group 
as a genus, but, for what reason we know not, has since 
changed the name to Hlanoides. The hawks of this group 
are readily distinguished from all others by the superior 
length of the second primary of their elongated wings ; by 
their bill, rounded above, curved from the base, and not 
toothed ; their hirsute cere, thick, short, and wholly reticulated 
tarsi, half-feathered before; toes entirely separated, and 
powerful nails. ‘The head is flattened above, the gape wide, 
and the eyes large, deep sunk, and with the orbits greatly 
projecting above. ‘The colours are also similar in the different 
* The word nature being taken in so many different acceptations, we 
think proper to state, that, with Ranzani, we mean by it “ the aggregate 
ot all created beings, and of the laws imposed on them by the Supreme 
Creator.” 

